UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Some dyes and intermediates from vanillin Cochrane, James Alton 1947

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1947_A7 C6 S6.pdf [ 1.34MB ]
Metadata
JSON: 831-1.0062320.json
JSON-LD: 831-1.0062320-ld.json
RDF/XML (Pretty): 831-1.0062320-rdf.xml
RDF/JSON: 831-1.0062320-rdf.json
Turtle: 831-1.0062320-turtle.txt
N-Triples: 831-1.0062320-rdf-ntriples.txt
Original Record: 831-1.0062320-source.json
Full Text
831-1.0062320-fulltext.txt
Citation
831-1.0062320.ris

Full Text

.1 SOME DYES AND INTERMEDIATES FROM VANILLIN JAMES ALTON COCHRANE A t h e s i s submitted i n p a r t i a l f u l f i l m e n t of the requirements f o r the degree of MASTER OF APPLIED SCIENCE i n the DEPARTMENT OF CHEMISTRY THE UNIVERSITY OF BRITISH COLUMBIA June 1947. by ABSTRACT An attempt was made to synthe s i z e dyes of the triphenylmethane s e r i e s , w i t h v a n i l l i n as a s t a r t i n g m a t e r i a l * Using conventional methods of dye p r e p a r a t i o n , s e v e r a l b r i l l i a n t dyes were obtained, but only one of these was f i n a l l y c r y s t a l l i z e d . A new method of triphenylmethane p r e p a r a t i o n was p a r t i a l l y i n v e s t i g a t e d . T h i s c o n s i s t e d of condensing 3 methoxy 4 benzoyl benzal c h l o r i d e , a new d e r i v a t i v e of v a n i l l i n , w i t h a r y l compounds c o n t a i n i n g auxoohrome groups. PREFACE The work described, i n the f o l l o w i n g pages i s p a r t of a study of v a n i l l i n which i s being o a r r i e d out at t h i s U n i v e r s i t y * I wish to acknowledge the generous a s s i s t a n c e of the Powell R i v e r Company L i m i t e d , whose s c h o l a r s h i p made t h i s research p o s s i b l e . I would l i k e t o acknowledge the guidance of Dr. R. H. C l a r k , under whose d i r e c t i o n t h i s work was done* A l s o I would l i k e t o thank Dr. R. F. P a t t e r s o n , of the Powell R i v e r Company, f o r h i s advice, and my c o l l a b o r a t o r of the past year, Mr* G. H a r r i s , f o r h i s help and advioe. J* A. Cochrane, June 1947. . TABLE OF CONTENTS In t r o d u c t i o n T h e o r e t i c a l D i s c u s s i o n -v C h a r a c t e r i s t i c s of D y e - s t u f f s C o n s t i t u t i o n and Depth of Colour The Quinonoid Theory Liebig»s Theory C h a r a c t e r i s t i c s of Triphenylmethane Method of Synthesis Experimental Conclusion SOME DYES AND INTERMEDIATES FROM VANILLIN INTRODUCTION The object of t h i s i n v e s t i g a t i o n was t o determine the p o s s i b i l i t y of condensing v a n i l l i n w i t h v a r i o u s compounds to form dyes of the triphenylmethane s e r i e s . V a n i l l i n . 3-methoxy 4-hydroxy benzaldehyde i s a by-product of the pulp and paper i n d u s t r y . I t has as yet very l i t t l e commercial use, compared to i t s huge p o t e n t i a l produc-t i o n , and du r i n g recent years many attempts have been made to f i n d p r o f i t a b l e uses f o r t h i s compound. Benzaldehyde and i t s analogs have l o n g been used i n the d y e s t u f f i n d u s t r y , but i t was not known i f v a n i l l i n , w i t h i t s a t y p i c a l r e a c t i o n s , would form triphenylmethanes. A search of the l i t e r a t u r e revealed t h a t a few suoh dyes had been synt h e s i z e d . I n 1884, 0. F i s c h e r ^ 1 ) , i n the course of p r e p a r i n g triphenylmethanes from a r y l aldehydes, condensed v a n i l l i n w i t h d i m e t h y l a n i l i n e t o g i v e a deep blue dye. 2. I n 19J9, some triphenylmethane dyes which are of the r a p e u t i c value were re p o r t e d by D o m i n i k i e w i o z ^ 2 ) . S e v e r a l condensations of v a n i l l i n and bourbonal ( e t h y l analog o f v a n i l l i n ) w i t h g u a i a c o l and g u e t o l ( e t h y l analog of gu a i a c o l ) are d e s c r i b e d . The d y e s t u f f from v a n i l l i n and g u a i a c o l CH«0 C has been intr o d u c e d r e c e n t l y , under the trade name Rubo-frene as a remedy f o r s k i n and bone t u b e r c u l o s i s . THEORETICAL DISCUSSION C h a r a c t e r i s t i c s of d y e - s t u f f s w / A l l substances possess a b s o r p t i o n bands* but only those which absorb.in the v i s i b l e r e g i o n of the spectrum w i l l appear coloured. The r e l a t i o n between c o l o u r and chemical s t r u c t u r e was f i r s t developed by 0. N. W i t t ^ 4 ^ i n I876. He po i n t e d out t h a t the d y e s t u f f molecule must possess a c e r t a i n group t o giv e i t the p o t e n t i a l i t y f o r c o l o u r , and i t must a l s o possess a s a l t - f o r m i n g r a d i c a l to b r i n g out the c o l o u r and dyeing p r o p e r t i e s . Croups which produce ab s o r p t i o n bands i n the v i s i b l e spectrum he c a l l e d ohromophores, and molecules c o n t a i n i n g them were c a l l e d chromogens. The more common ohromophore groups are: Such ehromogens as nitrobenzene and p~benzoquinone are coloured, but they do not have dyeing p r o p e r t i e s * - The colour i s developed or strengthened by the i n t r o d u c t i o n o f s a l t - f o r m i n g r a d i c a l s i n t o the ehromogens* These r a d i c a l s were t h e r e f o r e c a l l e d auxoehromes* Hydroxyl, amino, and s u b s t i t u t e d amino groups are the p r i n c i p a l auxoehromes* C o n s t i t u t i o n and Depth of Colour In I879 H i e t z k i ^ ) formulated a r u l e on the r e l a t i o n between c o n s t i t u t i o n and depth of c o l o u r * Colour chemists use the term "depth" i n a l i m i t e d way* The change of c o l o u r from y e l l o w to orange to red to v i o l e t t o blue to green i s known as a deepening of colour* H l e t z k i s t a t e d that the c o l o u r of a dye oan be deepened by adding groups to inorease i t s molecular weight and t h a t the deepening of c o l o u r produced i s more or l e s s p r o p o r t i o n a l to the i n c r e a s e of molecular weight* This r u l e holds w e l l i n the triphenylmethanes but o n l y p a r t i a l l y on other d y e - s t u f f s e r i e s . I n g e n e r a l , however, i t may be s a i d t h a t c e r t a i n groups produce a deepening of colour* Such, r a d i c a l s are c a l l e d bathoehrome groups, and i f they have the opposite e f f e c t are termed hypsochrome groups* Auxochrome r a d i c a l s , although not possessing any chromophorio p r o p e r t i e s , are e s p e c i a l l y e f f e c t i v e i n producing a deepening of c o l o u r * Methyl, e t h y l , and phenyl groups are a l s o u s u a l l y bathochromic, w h i l e the a c e t y l r a d i c a l e x e r t s a hypsochromic e f f e c t . 4. The Quinonoid Theory I n 1888, H, E. Armstrong^) formulated the quinonoid theory to e x p l a i n the r e l a t i o n between c o l o u r and c o n s t i t u t i o n . He p o i n t e d out t h a t the formulae of most dyes e i t h e r contained the quinonoid grouping or could be m o d i f i e d s l i g h t l y t o con-t a i n t h i s grouping. The quinonoid s t r u c t u r e i s d e f i n e d as a benzene nucleus to which other atoms o r groups are attached by double bonds i n the para or ortho p o s i t i o n As an example i t was q u i t e c o n s i s t e n t w i t h e x p e r i -mental f a c t to suppose t h a t p, - r o s a n i l i n e , on conversion of the base i n t o s a l t s , l o s t a molecule of water and formed a substance w i t h a quinonoid s t r u c t u r e Armstrong's quinonoid theory l e d t o much experimental work, the r e s u l t s of which have shown th a t the theory i s untenable. On one hand substances have been prepared which have a quinonoid s t r u c t u r e but are c o l o u r l e s s , and on the other hand coloured substances are known to whioh a quinonoid s t r u c t u r e cannot be assigned, A m o d i f i c a t i o n of the quinonoid theory was suggested by A t v, B a e y e r ^ , and a l s o by W i l l s t a t t e r ^ , Baeyer showed t h a t fuschoninime i s c o l o u r l e s s but that the i n t r o d u c t i o n of a p-amino group i n t o one of the phenyl groups cause the develop-ment of colo u r . N H * ° " c - o » H * ° " " c x - > c o l o u r l e s s coloured This and s i m i l a r f a c t s l e d Baeyer to suggest t h a t the cause of c o l o u r i s an o s c i l l a t i o n of the quinonoid con-d i t i o n between two or more benzene n u c l e i . Baeyer and W i l l s t a t t e r c o u l d not have meant t h a t suoh an o s c i l l a t i o n was the only oause of c o l o u r , as there are many coloured compounds which c o n t a i n only one benzene nucleus. L l e b l g s Theory The f a c t t h a t the fu l v e n e s are coloured, although (9) they do not c o n t a i n the quinonoid s t r u c t u r e l e d H. v. L i e b i g v / / t o suggest t h a t the e s s e n t i a l ohromophore i s the l i n k a g e i t n tt - A - A - A which i s possessed .by both quinonoid compounds and the f u l v e n e s . C Qcn+)x / / ~ V / cv C = <"">=NH-rt<U. H C - C H — dimethyl fulv.ene p - r o s a n i l l n e h y d r o c h l o r i d e As w i t h the quinonoid theory, however, L i e b i g s theory does not e x p l a i n the many coloured compounds which do not » » » contain the A - A - A l i n k a g e , nor the c o l o u r l e s s compounds which do co n t a i n t h i s l i n k a g e . Although the e a r l y t h e o r i e s of W i t t , Armstrong and L i e b i g have been shown to be ho longer tenable, and Hiet2&e*s r u l e i s only p a r t i a l l y t r u e , n e v e r t h e l e s s , i t i s these t h e o r i e s and r u l e s whioh.were r e s p o n s i b l e f o r the d i s c o v e r y of most of the important dyes, and they are s t i l l e x c e l l e n t guides t o a colo u r chemist i n h i s search f o r new c o l o u r i n g matters* C h a r a c t e r i s t i c s of Triphenylmethanes The members of t h i s c l a s s o f dyes have the most b r i l l i a n t shades and the g r e a t e s t t i n c t o r i a l power of any c l a s s of c o l o u r i n g matters* On the other hand, they are not very f a s t t o l i g h t , but they do f i n d c onsiderable use where the l i f e of the dyed m a t e r i a l i s short* Gomberg^ 1 0) d i d considerable work on the s t r u c t u r e of the triphenylmethanes. I t was n o t i c e d , when the mo d i f i e d quinonoid theory was formulated, t h a t t h i s theory c o u l d apply very n i c e l y to the triphenylmethane dyes* Comberg, however, was the f i r s t to o b t a i n any d i r e c t evidence f o r the c o r r e c t -ness of the tautomeric view by preparing the two desmotropic forms of a t r i p h e n y l o a r b i n o l * He found t h a t para-hydroxy-t r i p h e n y l c a r b i n o l e x i s t e d i n both the coloured and c o l o u r l e s s m o d i f i c a t i o n * The two forms were i s o l a t e d i n the c r y s t a l l i n e s t a t e and were assigned the s t r u c t u r e s : -Since then* many t r i p h e n y l c a r b i n o l s have been i s o -l a t e d i n two d i s t i n c t forms, the c o l o u r l e s s benzenoid, and the coloured quinonoid* The type obtained depends on the s o l v e n t used f o r c r y s t a l l i z a t i o n * A l s o , the white m o d i f i c a t i o n w i l l change t o the coloured by the a p p l i c a t i o n o f heat* METHODS OF SYNTHESIS One of the most general methods o f sy n t h e s i s o f triphenylmethane dyes i s the condensation of an a r y l aldehyde w i t h two molecules of an aromatic base, i n the presence of ' some condensing agent* m 1884, 0* F i s c h e r ^ condensed v a n i l l i n w i t h d i -m e t h y l a n i l i n e , and i t was f e l t t h a t some s i m i l a r compounds oould be synthesized* Not only i s v a n i l l i n an a r y l aldehyde, but the auxoohromic hydroxy group would apparently make i t appear as an a t t r a c t i v e s t a r t i n g m a t e r i a l f o r d y e s t u f f s * F i s h e r s s y n t h e s i s was repeated i n our l a b o r a t o r y , and a dye was obtained w i t h the same c h a r a c t e r i s t i c s as h i s compound* The leuco base was prepared by d i s s o l v i n g v a n i l l i n i n a s l i g h t molecular excess of d i m e t h y l a n i l i n e , and w i t h con-stant s t i r r i n g a t 100°C, adding the condensing agent, powdered anhydrous z i n c c h l o r i d e ; The r e a c t i o n mixture became coloured almost immediately, changing from red t o purpl e as the r e a c t i o n progressed* The equation f o r the r e a c t i o n i s : Y i e l d s f o r t h i s r e a c t i o n were d i f f i c u l t t o o b t a i n , i n that the crude leuco- base was an amorphous, s t i c k y m a t e r i a l An approximate e v a l u a t i o n was obtained from the amount o f a i m e t h y l a n i l i n e recovered, i n d i c a t i n g a y i e l d of 30 - 40f o. A dark red s o l u t i o n was obtained on d i s s o l v i n g the red c r y s t a l s of leuco- base i n d i l u t e h y d r o c h l o r i c a c i d * A f t e r o x i d a t i o n , the s o l u t i o n turned dark blu e . The s a l t i s q u i t e s o l u b l e i n water, and dyes paper and c l o t h dark blue* The l e u c o - base, 3 methoxy, 4 hydroxy 4 f, 4" t e t r a -e t h y l diamine triphenylmethane was prepared i n an e n t i r e l y s i m i l a r way to the t e t r a m e t h y l compound* The l e u c o - base oould not be c r y s t a l l i z e d * A r e s i n o u s sludge, probably a polymer, and having about the same s o l u b i l i t y as the dye, i n t e r f e r e d i n every c r y s t a l l i z a t i o n * Upon o x i d a t i o n i n a c i d s o l u t i o n , however, the dye changed from dark f e d t o green, and was p r e c i p i t a t e d n i c e l y as a double z i n c c h l o r i d e i n saturated brine*. The s a l t i s s o l u b l e i n water and dyes paper and o l o t h emerald green* Another standard method of producing triphenylmethane dyes i s the condensation of a r y l aldehydes w i t h o- hydroxy benzoic a c i d d e r i v a t i v e s having the para p o s i t i o n t o the hydroxy! group f r e e * Eriochrome Cyanine R (CI 1ZZ)0-^ i s obtained from benzaldehyde o- sulphoaio a c i d and o- o r e s o t i o a c i d w i t h subsequent o x i d a t i o n . p f - ' . M M The condensation of v a n i l l i n w i t h s a l i c y l i c ' a c i d , and w i t h o- o r e s o t i c a c i d was attempted. I f we expect v a n i l l i n t o behave as a normal a r y l aldehyde the r e a c t i o n w i t h s a l i -c y l i c a c i d should be The v a n i l l i n was heated w i t h an excess of s a l i c y l i c a c i d , u s i n g z i n c c h l o r i d e as condensing agent. The product was a b r i t t l e amorphous s o l i d , which gave an inte n s e p u r p l e colour when d i s s o l v e d i n d i l u t e a l k a l i . I t would not c r y s t a l l i z e from about t e n o r d i n a r y s o l v e n t s . A mixed s o l v e n t , of l i g r o i n and e t h y l a c e t a t e , p r e c i p i t a t e d a red o i l on f r e e z i n g , which d i d not c r y s t a l l i z e even a f t e r l o n g standing* V a n i l l i n and o r e s o t i c a c i d behaved i n much the same manner* When these two reagents were melted together no change was n o t i c e d u n t i l a l i t t l e powdered z i n c c h l o r i d e was added* The melt immediately turned red, darkening as the r e a c t i o n progressed* The product was a n o n - c r y s t a l l i n e purple s o l i d whioh gave an intense purple dye s o l u t i o n when d i s s o l v e d i n d i l u t e a l k a l i * As w i t h the s a l i c y l i c a c i d dye, a c o l o u r change from purple t o r e d was n o t i c e d when the s o l u t i o n was a c i d i f i e d . During the course of these experiments i t was n o t i c e d that v a n i l l i n would gi v e a dark red c o l o u r a t i o n when heated w i t h s e v e r a l compounds, but only a f t e r a l i t t l e z i n c c h l o r i d e was added. V a n i l l i n , i t s e l f , when heated w i t h z i n c c h l o r i d e , formed a red s o l i d which d i d not d i s s o l v e i n hot ether, and had no m e l t i n g p o i n t up t o ?00°G* A f t e r d i s s o l v i n g t h i s s o l i d i n - 10. d i l u t e sodium hydroxide and n e u t r a l i z i n g , the c o l o u r l e s s v a n i l l i n was recovered. I t appears that v a n i l l i n forms some unstable polymer. Since i t was probable t h a t the s t r a i g h t condensation of v a n i l l i n w i t h other compounds produces polymers under the a c t i o n o f z i n c c h l o r i d e , and since the y i e l d of d y e s t u f f i n any case was poor, i t was decided t o t r y a d i f f e r e n t method of s y n t h e s i z i n g triphenylmethanes. MacKenzie^ 1 2^ had made 4, 4 h y -droxy triphenylmethane by h e a t i n g benzal c h l o r i d e w i t h phenol. A d e r i v a t i v e of v a n i l l i n , 3 methoxy, 4 benzoyloxy benzal c h l o r i d e was prepared i n t h i s l a b o r a t o r y f o r the f i r s t time by r e a c t i n g benzoyl v a n i l l i n w i t h e i t h e r t h i o n y l c h l o r i d e or phosphorus pe n t a o h l o r i d e . The r e a c t i v e para- hydroxy group was blocked by b e n z o y l a t i n g . E x c e l l e n t y i e l d s were obtained by both methods. The compound has a m e l t i n g p o i n t o f 98.0 - 98.j>°C and was analyzed f o r c h l o r i n e content, the r e s u l t s of which were: percent c h l o r i n e , c a l c u l a t e d 22.8$£; found 22.74%. I t was shown that the c h l o r i n e r e p l a c e d the carbonyl oxygen i n -stead o f e n t e r i n g the r i n g , because an a l c o h o l i c s o l u t i o n of s i l v e r n i t r a t e gave a q u a n t i t a t i v e p r e c i p i t a t i o n of s i l v e r c h l o r -i d e . Somewhat l a t e r , a short reference was found to the cor-responding 3 methoxy, 4 benzoyloxy benzal bromide, which had been prepared I n 1934 °y R a i f o r d and M i l b e r y ^ 1 ^ ) , In the method o u t l i n e d by MaoKenzie the benzal c h l o r i d e reacted w i t h phenol according to the equation:-O c " a ^ a- Q - " — Q - c - ( O * K + 2 H a ' i t was thought t h a t , u s i n g the same type r e a c t i o n , the 3 methoxy, 4 benzoyl benzal c h l o r i d e could be condensed w i t h s e v e r a l compounds c o n t a i n i n g auxochrome groups* I n the f i r s t of these attempts, 3 methoxy 4 benzoyl benzal c h l o r i d e was heated w i t h phenol, as i n MacKenzie's experiment* The excess phenol was d i s t i l l e d o f f under vacuum, l e a v i n g a dark red amorphous s o l i d j which r e f u s e d t o c r y s t a l l i z e from s e v e r a l s o l v e n t s * This product, u n l i k e the former ones, d i d not possess any dyeing p r o p e r t i e s , and was probably polymerized m a t e r i a l * The next sy n t h e s i s t r i e d o o n s i s t e d of d i s s o l v i n g 3 methoxy 4 benzoyl benzal c h l o r i d e i n dimethyl a n i l i n e and h e a t i n g f o r s e v e r a l hours* The product was a green s o l i d , somewhat c r y s t a l l i n e , w i t h a m e l t i n g p o i n t of 135 * 143°C* R e p r e o i p i t a t i o n from s e v e r a l solvents gave green or white o i l s , - which refused to c r y s t a l l i z e even a f t e r standing* The expected r e a c t i o n was:-The same r e a c t i o n was repeated, u s i n g p y r i d i n e as a s o l v e n t * P y r i d i n e was used, sinoe i t would form p y r i d i n e -h y d r o c h l o r i d e , removing the hydrogen c h l o r i d e formed d u r i n g the r e a c t i o n * The c r y s t a l s of p y r i d i n e h y d r o c h l o r i d e were f i l -t e r e d o f f , and the excess d i m e t h y l a n i l i n e and p y r i d i n e was removed w i t h steam* The product oo n s i s t e d of dark green c r y s t a l s w i t h an i n d i s t i n c t m e l t i n g p o i n t of 130° - 140°. Upon d i s s o l v i n g t h i s product i n d i l u t e h y d r o c h l o r i c a c i d , and 12. reducing w i t h z i n c dust x, a white s o l i d p r e c i p i t a t e was obtained, whioh softened and turned green a t 13£°C* and f i n a l l y melted t o a green l i q u i d a t 190°C. A l l m e l t i n g p o i n t s during t h i s research were made i n the F i s h e r e l e c t r i c m e l t i n g - p o i n t appar-atus i n whioh the compound i s h e l d between two g l a s s s l i d e s . Thus some a i r c o u l d come i n t o contact w i t h the compound and cause o x i d a t i o n at hig h e r temperatures. I t was found t h a t r a t h e r d r a s t i c treatment was necessary t o hydrolyze the benzoyl group which had been used t o b l o c k the ph e n o l i c hydroxy r a d i c a l . B o i l i n g the dye w i t h a c i d not only r e l e a s e d benzoic a c i d , but i t a l s o destroyed the dye i t s e l f . . Because a c e t y l groups hydrolyze more e a s i l y i t was decided to t r y the sy n t h e s i s of 3 methoxy 4 - a c e t y l benzal c h l o r i d e as a.dye inte r m e d i a t e . A c e t y l v a n i l l i n was made by the method of P i s o v s e h i ^ 4 A d d i t i o n of phosphorus pentaohloride to t h i s compound produced a c l e a r o i l which was probably the expected compound, but whioh was so unstable t h a t i t decomposed, i n a few hours. R e c r y s t a l -l i z a t i o n from s e v e r a l s o l v e n t s was t r i e d , but the compound's i n s t a b i l i t y prevented any a n a l y s i s . I n any case, i t was of no use as a triphenylme thane i n t e r m e d i a t e . One f u r t h e r compound was made during the course of t h i s r e s e a r c h . By a method of K h o e v e n a g e l ^ ) , 3 methoxy 4-benzoyl-benzal -diacetate was synthesized from benzoyl v a n i l l i n and a c e t i c anhydride, u s i n g z i n c c h l o r i d e as c a t a l y s t . The white c r y s t a l s melted at 107°C. As 7 e t the new compound has not been analyzed. 13. EXPERIMENT AL 3 methoxy, 4 hydroxy. 4*, 4" t e t r a m e t h y l diamino triphenylmethane. O " ^ « > ^ V a n i l l i n (14 g) was d i s s o l v e d i n 23 g (10% excess) of r e d i s t i l l e d d i m e t h y l a n i l i n e , the mixture was heated w i t h s t i r r i n g on a water-hath, and 10 g of dry powdered z i n c c h l o r -ide was slowly added. The temperature was kept at 100°C f o r 20 hours, then r a i s e d to 110°C f o r 2 hours. The t h i c k blue melt was b o i l e d up w i t h water and steam d i s t i l l e d , to remove the excess d i m e t h y l a n i l i n e . A f t e r decanting, the z i n c c h l o r i d e l i q u o r , the residue was taken up i n e ther. On slow evaporation of the s o l v e n t , dark r e d c r y s t a l s p r e c i p i t a t e d . The dye was r e c r y s t a l l ! z e d from absolute ether, and had a m e l t i n g p o i n t of 132 - 133°• Oxi d a t i o n o f the Leuoo - base The leuoo-base (10 g) was d i s s o l v e d i n 70 co of hot 2N h y d r o c h l o r i c a o i d and d i l u t e d t o 800 cc w i t h water. To the d i l u t e d s o l u t i o n , kept c o o l i n i c e , and w e l l shaken, was added 8 g of f r e s h l y prepared l e a d d i o x i d e ^ ) i n suspension. The s o l u t i o n immediately changed from a dark wine to a green blue c o l o u r . The z i n c c h l o r i d e double s a l t was formed by adding t o the dye s o l u t i o n a concentrated s o l u t i o n of z i n c c h l o r i d e (10 g) and was p r e c i p i t a t e d by the a d d i t i o n o f saturated b r i n e . 14. 3 methoxy, 4 hydroxy t 4*. 4 W t e t r a e t h y l diamlno triphenylmethane. V a n i l l i n (14 g) was d i s s o l v e d i n 31 g (10% exoess) of r e d i s t i l l e d d i e t h y l a n i l i n e , the mixture was heated w i t h s t i r r i n g on a water hath, and 10 g of dry powdered z l n e c h l o r -ide was s l o w l y added. The temperature was kept at 100°C f o r 18 hours and f i n a l l y r a i s e d t o 110° f o r 3 hours. The dark red melt was b o i l e d up w i t h water and steam d i s t i l l e d , 16 g o f d i e t h y l a n l l i n e b eing recovered. The unre-acted v a n i l l i n was removed w i t h hot water. O x i d a t i o n of the l e u c o - base. The crude leuco base (12 g) was d i s s o l v e d i n 8 0 c e of hot 23ST h y d r o c h l o r i o a c i d and was d i l u t e d to 800 co. To the d i l u t e d s o l u t i o n , kept c o o l i n i c e , and w e l l shaken, was added 8 g of l e a d d i o x i d e i n suspension. To the r e s u l t i n g green s o l u t i o n was added z i n c c h l o r i d e (10 g) and the double s a l t was p r e c i p i t a t e d w i t h s a t u r a t e d b r i n e . 3 methoxy, 4 hydroxy, 3T» 3 n djoarboxy, 4*. 4" dlhydroxy t riphenylmethane. > Off-V a n i l l i n (20 g) and s a l i c y l i c , a c i d (42 g) were heated together i n a round-bottomed f l a s k , and powdered anhydrous z i n c 13. c h l o r i d e (10 g) was s l o w l y added w i t h constant s t i r r i n g . She r e a c t i o n mixture turned b r i g h t red on the a d d i t i o n of the z i n c c h l o r i d e * The temperature was h e l d at 130°C f o r 5 hours* vents even a f t e r c onsiderable standing* Sulphonation was t r i e d t o make the dye water s o l u b l e . The crude product (1 g) was s t i r r e d w i t h 60 cc fuming s u l p h u r i c a c i d * and kept c o o l i n i c e , u n t i l s o l u t i o n was e f f e c t e d * The a c i d s o l u t i o n was then dripped s l o w l y i n t o c o l d s a t u r a t e d b r i n e from a dropping f u n n e l * The p r e o l p i t a t e was a n o n c r y s t a l l i n e m a t e r i a l which s i n t e r e d i n the m e l t i n g - p o i n t apparatus* The product d i s s o l v e d i n d i l u t e sodium hydroxide t o g i v e a deep purp l e dye s o l u t i o n * 3 methoxy, 4 hydroxy, 3 1 * 3* dloarboxy, 4*. 4* dlhydroxy,  5*. 5" dimethyl triphenylmethane melted together i n a round-bottomed f l a s k , powdered anhydrous z i n c c h l o r i d e (10 g) was added w i t h s t i r r i n g , and the whole was heated at 130° f o r 4 hours* The r e s u l t i n g dark r e d amor-phous s o l i d was powdered and e x t r a c t e d w i t h chloroform t o remove the unreacted v a n i l l i n and c r e s o t i o a c i d * The r e s i d u e would not c r y s t a l l i z e from a number of s o l v e n t s * The crude product would not c r y s t a l l i z e from s o l -V a n i l l i n (13 g) and o~ c r e s o t i o a c i d (30 g) were 16. Benzoyloxy v a n i l l i n V a n i l l i n (30. g) was d i s s o l v e d i n p y r i d i n e (40 g) and 40 g of benzoyl c h l o r i d e was s l o w l y added w i t h constant s t i r r i n g . A f t e r 13 minutes, the r e a c t i o n mixture was poured i n t o 300 co. of water, and the white p r e c i p i t a t e was washed w i t h c o l d water. The product was r e e r y s t a l l ! z e d twice from a l c o h o l , t o give white c r y s t a l s w i t h a m e l t i n g p o i n t of 74.3°C. The y i e l d was 70% of t h e o r e t i c a l . 3 methoxy. 4 benzoyloxy, benzal c h l o r i d e - Method 1. Benzoyl v a n i l l i n (20 g) was r e f l u x e d w i t h t h i o n y l c h l o r i d e (13 g) f o r 1& hours. A f t e r the e v o l u t i o n of sulphur d i o x i d e ceased, l i g r o i n was added through the r e f l u x condenser, h e a t i n g was continued f o r 10 minutes more, and f i n a l l y the product was allowed t o c r y s t a l l i z e out from the hot l i g r o i n . A f t e r two r e o r y s t a l l i z a t i o n s from l i g r o i n , the c r y s t a l s melted at 96 .3 - ?7«0°« The y i e l d was 93% t h e o r e t i c a l . 3 methoxy, 4 benzoyloxy benzal c h l o r i d e - Method 2. Benzoyl v a n i l l i n (20 g) and phosphorus pentaohloride (16 g) were mixed i n a s m a l l round-bottomed f l a s k ; the f l a s k was sealed w i t h a calcium c h l o r i d e tube, and was heated on a - - -- - - - - - 17. water bath, f o r hour. The melt was poured i n t o water, and the product, a f t e r t r i t u r a t i o n w i t h water, was f i l t e r e d and. washed. H e o r y s t a l l i z a t i o n from a l c o h o l gave white c r y s t a l s m e l t i n g p o i n t 96° - 97°C The y i e l d was 95%. A n a l y s i s of 3 methoxy 4 benzoyloxy benzal c h l o r i d e . The product was r e o r y s t a l l L z e d three times from a l c o h o l , and d r i e d i n a d r y i n g - p i s t o l f o r 4 hours. The c r y s t a l s were s m a l l shiny needles w i t h a m e l t i n g p o i n t of 98.0 - ? 8 . 3°C The method of Drogin and Rosanoff was f i r s t used t o f i n d the percentage c h l o r i n e . Weighed samples of the compound were d i s s o l v e d i n absolute a l o o h o l , and an excess of m e t a l l i c - sodium was added. A f t e r a l l the sodium had d i s s o l v e d , the mixture was d i l u t e d w i t h water, a c i d i f i e d w i t h n i t r i c a c i d and the c h l o r i d e present measured by Volhard*s method. The r e s u l t s were as f o l l o w s r e -c a l c u l a t e d % 01 22.85$ Found % CI 23.1, 23-2% A g r a v i m e t r i c method was next used f o r the de t e r -m i n a t i o n of the c h l o r i n e present, c o n s i s t i n g of the p r e c i p i -t a t i o n , of s i l v e r c h l o r i d e w i t h a l c o h o l i c s i l v e r n i t r a t e , and subsequent weighing o f t h e . s a l t . The s i l v e r n i t r a t e was d i s s o l v e d i n 80% a l o o h o l , which had been p r e v i o u s l y d i s t i l l e d and d i l u t e d w i t h d i s t i l l e d water* The compound was d i s s o l v e d i n 80% a l c o h o l * a s l i g h t excess of s i l v e r n i t r a t e s o l u t i o n was added, and the whole was dig e s t e d f o r two hours a t 6»0°C* The p r e c i p i t a t e was weighed i n a Gooch c r u c i b l e * The r e s u l t s were as f o l l o w s : -C a l c u l a t e d % CI 22.8.5 Pound % CI 22.77, 22.70 3 methoxy. 4 acetoxy benzal c h l o r i d e . One mole o f a c e t y l v a n i l l i n (20 g) was mixed w i t h 1.23 moles of phosphorus pentaehloride i n a f l a s k c l o s e d w i t h a d r y i n g tube. The f l a s k was heated on a water^bath; the reaotants melted r a p i d l y j and a b r i s k r e a c t i o n was observed. On pouring the melt i n t o water, a c l e a r o i l was formed. How-ever; the compound decomposed r a p i d l y , and a m e l t i n g - p o i n t was not obtained. The r e a c t i o n was repeated s e v e r a l times, u s i n g d i f f e r e n t s o l v e n t s f o r r e c r y s t a l l i z a t i o n , but i n each case decomposition occurred w i t h i n one or two hours. 5 methoxy, 4 benzoyl, 4*» 4" dioxy triphenylmethane.. ° J — \ y —/ t A l a r g e excess of phenol (33 s) w a s heated w i t h 3 methoxy, 4 benzoyl b e n z a l c h l o r i d e (14 g) f o r 14 hours a t 120°C. The excess phenol was d i s t i l l e d o f f under vacuum (l6mm p r e s s u r e ) , l e a v i n g very l i t t l e of a dark r e d amorphous m a t e r i a l . Ro c r y s t a l s were obtained, even a f t e r b o i l i n g up w i t h decolour-i z i n g c h a r c o a l i n s e v e r a l s o l v e n t s . 3 methoxy 4 benzoyl, 4', 4" t e t r a m e t h y l , d l amino triphenylmethane. t 1?. A 30% excess of d i m e t h y l a n i l i n e (12 g) was heated w i t h 3 methoxy 4 benzoyl benz a l c h l o r i d e (10 g) f o r 18 hours at 120°C. The mixture g r a d u a l l y turned green. Upon adding hot water t o the f l a s k a strong s m e l l of hydrogen c h l o r i d e was n o t i c e d . The excess d i m e t h y l a n i l i n e was steam d i s t i l l e d . On evaporating the water s o l u t i o n a green s o l i d was obtained w i t h a m e l t i n g p o i n t of 140 - 130°. The r e a c t i o n was repeated, u s i n g p y r i d i n e as a s o l v e n t . D i m e t h y l a n i l i n e (12 g ) , and 3 methoxy 4 benzoyl benzal c h l o r i d e ClO g) were d i s s o l v e d i n 40 co of p y r i d i n e . The s o l u t i o n was r e f l u x e d f o r 14 h r s at 110°C. The c r y s t a l s o f p y r i d i n e hydro-c h l o r i d e were f i l t e r e d o f f , the s o l u t i o n was adjusted to a pH of 7 . 3 , and the excess d i m e t h y l a n i l i n e and p y r i d i n e were r e -moved w i t h steam. Green c r y s t a l s were obtained on evaporation, w i t h a m e l t i n g p o i n t of 130 - 140°C. Some of the product was reduced w i t h z i n c i n h y d r o c h l o r i c a o i d , g i v i n g ' a white p r e c i p i -t a t e which turned green a t 133° and melted at 190°0. 3 methoxy. 4 benzoyl, benzal d i a o e t a t e Benzoyl v a n i l l i n (13 g ) , a 20% excess of a c e t i c anhydride (7 g) and 0.3 g anhydrous z i n c c h l o r i d e were shaken up together i n a f l a s k i which was sealed and l e f t at room temperature f o r s e v e r a l days. The product was r e o r y s t a l l i z e d from a l c o h o l , to a m e l t i n g p o i n t of 107°C. £be y i e l d was 20. 76% of theoretical. CONCLUSION The object of this research was to condense v a n i l l i n with various compounds to form triphenylmethane dyes. Although the reactions of v a n i l l i n have been found to he decidedly not typical of aryl aldehydes, i t i s possible to synthesize some dyes from this compound. With dimethylaniline and diethylaniline, v a n i l l i n w i l l form triphenylmethanes with good dyeing properties. Vanillin condensed with s a l i c y l i c and o- cresotio acids to form dyes of indeterminate structure. The compound 3 methoxy 4 benzoyl benzal chloride shows more promise as a dyestuff intermediate. It reacts i n considerably less time than v a n i l l i n , and gives an almost Quantitative yield* .Economically, the present price of v a n i l l i n makes a low yield one-step synthesis, or even a high yield two-step synthesis rather expensive as a method of triphenylmethane manufacture* BIBLIOGRAPHY 1. O, Fischer and C, Schmidt, Ber (17) - 189$ 2. M. Dominikiewicz, Arch. Chem. Form 4 , ^8-68 (1939) 3. F.R.Watson. Colour i n Relation to Chemical Constitution, Longmans, Green and Co., 1918. 4 . 0 . 3ST. Witt, Ber. 9, 322. 3. Hletzki. 7erhandl des Vereins zum Beforderung des Gewer-hefleisses, I879, 38j 231. 6. H. E. Armstrong; Proo. Chem. Soc. l88c),pp.27 -33. 7. A. v. Baeyer; Jour. Chem. Soc. Abs. 1907 i , 3 0 4 . 8* R. Willstatter and J. Pioard, Ber. 1908, 14, 1438* 9. H. v. Liebig, Annalen 1908, 360, 128. 1 0 . M. Gomherg and IT. E. Tan Stone, JACS 38, 1377. 11 . Colour Index, London, 1922. 12 . Mackenzie, Soo. 79 - 1216. 13. C. Raiford and J. Milbery, JAGS* 36j 27E7* 14. I. Pisovsohi, Ber. 4 3 , 2137 (1910) 13. E. Khoevenagel, Annalen 402, 117* 16. L. Gattermann, Laboratory Methods of Organic Chemistry, * P. 323. 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0062320/manifest

Comment

Related Items