This 14 page thesis examines the classification and preparation of dyes

Cramer, Faith B.

English

Ursinus College

Ursinus College Digital Commons @ Ursinus College Chemistry Honors Papers Student Research 9-1944 Synthesis of Dyes Faith B. Cramer Follow this and additional works at: https://digitalcommons.ursinus.edu/chem_hon  Part of the Chemistry Commons Click here to let us know how access to this document benefits you. Ursinus College L i b r a r y , URCINUSIAMA COLLECTION Class 0 Boxg/Wr^ Synthesis of Dyes F a i t h B. Cramer, C6<J.^(i^/^f^5^ Department Honors Ursinus College September, 1944 This paper i s submitted i n p a r t i a l f u l f i l l m e n t of Department Honors. Group Adviser Introduotion The dyeing property i s dependent wgon s t r u c t u r e ; The charact-er 'of the l y e s t u f f i s derived from some group contained i n i t , c a l l e d the chromophore.The most important chromophores are C:C, C:0,C:S,C:N,N:N,N:0,ji:0,..Chromophores vary i n t h e i r e f f e c t i v e -ness to produce c o l o r . I n general,color deepens as the molecular weight i n c r e a s e s , e s p e c i a l l y as the number of chromophores i n -creases . The fundamental substance containing the chromophore i s the chrom.ogen. The chromogen i s not a dyestuff,but i s converted i n t o t h i s by the entrance of some salt-forming group which de-s t r o y s the chemically i n e r t character of the chromogen. The groups conferring salt-forming properties upon the chromogen are auxochromes,which f a l l i n to two groups: a)acidic:SO,H, COOH, OH B] b)basic:KH,,, NHR, NRo. Often ajbolorless chromogen becomes colored upon introduction of an auxochrome.Benzophenono,for example,becomes yellow when -NHi group i s introduced.Azobenzene,which i s red,becomes a dye when -NHĵ  i s intiDoduced i n the para p o s i t i o n , C e r t a i n auxochromes have a higher e f f e c t i v e n e s s than others. Generally speaking,only those organic compounds containing a c i d or basic groups can be dyestuffs.They are unsatiirated,read-i l y reduced by nascent hydrogen,producing leuco compounds .'the leuco compounds,in t u r n , y i e l d the dyestuff again upon oxidation, or break up into bodies of lower molecular weight,which are not reconverted by oxidation. I n dye manufacture, there c e r t a i n " o r i g i n a l substances,such as benzene,naphthalene,anthracene,phenol,cresol,etc.—coal t a r d e r i v a t i v e s — w h i c h by various means are converted i n t o " i n t e r -mediates". T>,e intermediates are such compoimds as w i l l by simple r e a c t i o n s form the dyes.They comprise: a) n i t r o compounds ( n i t r o b e n z e n e , n i t r o a n i l i n e ) b) amine compounds (aniline,toluidine,naphthylamine) c) p h t h a l i c acids (phthalimide,phthalic anhydride) d) s u l f o n i c acids e) halogen compounds f ) phenolic compounds and aminophenols g) aldehydes and c a r b o x y l i c acids h) d e r i v a t i v e s having s e v e r a l functions w i t h i n the molecule (mixed compounds). C l a s s i f i c a t i o n of Dyes Dyes are v a r i o u s l y c l a s s i f i e d . T h e common methods are accord-ing to (a)whether the dyes are a c i d i c or b a s i c ; (h^imethod of a p p l i c a t i o n ; ( c ) s t r u c t u r e of the dye. Those dyes containing -NH,. ,-NHR, -NR^ groups w i l l form s a l t s with acids and are termed basic.Those possessing -SO H and COOH,or -OH,groups form s a l t s w i t h bases and are termed a c i d dyes. Some of the general c l a s s i f i c a t i o n s according to method of a p p l i c a t i o n are ( l ) substantive dyes,or d i r e c t dyes;(2)ad-j e c t i v e or mordant dyes;and(3)ingrain dyes.Substantive dyes adhere d i r e c t l y to the c l o t h to be dyed without the aid of sup-plementary chemicals.Mordant dyes are unable to dye d i r e c t l y , but may do so with the aid of a mordant,usually the hydroxides or basic s a l t s of aluminnm,chromium,tin and iron,which form ins o l u b l e compounds with the d y e s . I f the c l o t h i s f i r s t dipped i n a s o l u t i o n of the mordant,the in s o l u b l e dye-mordant compound i s f i r m l y f i x e d w i t h i n the f i b e r as i t forms.Ingrain dyes are a c t u a l l y formed w i t h i n the c l o t h as the r e s u l t of chemical a c t i o n between two substannes w i t h 'the c l o t h i s s u e c e s s i v e l y t r e a t e d . Vat dyeing i s s i m i l a r . Chemically,dyes are c l a s s i f i e d according to structure.The syntheses done i n connection w i t h t h i s paper were chosen by t h i s means.The general scheme f o l l o w s ; Name gf dyestuff Chromophore Typicaj i y e s t u f f Synthesized i n ' l.Nitroso or oxime «0 W«H £UAAAZ^ ^ l ^ A J t ^ 2.Nitro 3.AZ0 4.Triphenyl-methane 5.Oxyketone UJU OJi 6.Pyronines 0 7.Diphenylamines (a)Indamines (•b)lndophenols ( c ) T h i a z i n e s (d)0xazines ( e ) S a f r a n i n e s CCHp/ />»XjAl^-ydA«^ "CttA^ "0 J*pAAndyy Laboratory Preparations 1. Past Green 0 2. Naphthol Yellow S 3. Magenta 4. Eosin 5. Methylene Blue 6. Methyl Orange 7. Purpnrin PAST GREEN 0 (RESORCIN GREEN) (a)chemicals: Resorcinol 20 gms. Concentrated HCl 45 gms. Sodium n i t r i t e 25.5 gms. Sodium chloride 100 gms. (h)procedure:The r e s o r c i n o l i s dissolved i n 800 c c . w a t e r and the hydrochloric acid added together with 100 gms. s a l t . I c e i s added u n t i l the temperature i s 0*0,and into t h i s s o l u t i o n which i s s t i r r e d mechanically,the sodium n i t r i t e dissolved i n 100 cc. water i s allowed to flow very slowly,the temperatuFe.; not being allowed to r i s e above 8*C.This takes about a h a l f hour. »Vhen a l l the n i t r i t e has been added,the l i q u i d shows a f a i n t l y a c i d r e a c t i o n . A f t e r standing f o r one hour,the brownish-yellow p r e c i p i t a t e i s filtered,washed w i t h i c e - c o l d water and the paste dried on a porous plate.The y i e l d obtained was 34.6 gms. ( c ) p r o p e r t i e s : Greyish-brown powder,soluble i n hot water. Dyes iron-mordanted cotton green; iron-mordanted wool dark green. (d) equation': + (I NAPHTHOL YELLOW S (a) chemicals: a-Naphthol 100 gms. Concentrated Hj.30.̂  400 gms. Concentrated HN0jl74 gms. Sodium carbonate Potassium chloride 75 gms. (b) procedure: The s u l f u r i c acid i s warmed to lOO'C i n a round-bottom, flask,and the naphthol (powdered) i s added a l l at once.The temperature i s now r a i s e d to 120' and kept a t t h i s point f o r 3-4 hours.The s u l f o n a t i o n mixture i s then poured into 500 cc.water and s t i r r e d mechanically.As soon as the temperature i s about 30",the s o l u t i o n i s poured into a mixture of 90 gms. HNO^and 33 cc. water,the temperature being kept below 35".A f u r t h e r 84 gms. HNOjis now added,during which addition the temp-erature may r i s e t4 40°.The n i t r a t i o n mixture is^ now f i l t e r e d on woollen cloth.According to Cain and Thorpe,it i s washed f r e e from acid with s a l t solution;the drained paste s t i r r e d with hot water at 80°, sodium carbonate added u n t i l neut±al,and the dyestxiff p r e c i p i t a t e d by adding potassium chloride.However,the n i t r a t i o n mixture passed through the c l o t h e a s i l y , s o the s o l u t i o n was simply heated to 80',the sodium carbonate added,etc.The prec-i p i t a t e d dye i s f i l t e r e d and dried on a porous plate.The dye appeared as a muddy-yellow wet powder.Yield:61.6 gms. Attempts to f i n d a solvent s u i t a b l e f o r p u t i f i c a t i o n of the dye wewe unsa t i s f a c t o r y . A portion of the dye was r e c r y s t a l -l i z e d from hot alcohol;three l i t e r s of a3)Cohol yielded 2.4 gms. pure•dye.After recovery of the alcohol,another gram of dye was obtained. ( c ) p r o p e r t i e s : orange-yellow powderjdyes wool and s i l k yellow from an acid bath. (d) equation: I'JiiiGENTA (a ) chemicals: A n i l i n e 20 gms. Commercial toluidine—64^ortho,36^para ConcentratedHCl 67 gms. Nitrobenzene 55 gms. I r o n wire 3 gms. (b) procedure: 14 gms. a n i l i n e and 54 gms. t o l j i i d i n e are mixed together i n ajporcelain basin and the HCl added.The mix-ture of hydrochlorides i s heated u n t i l the temperature i s 130° when i t i s t r a n s f e r r e d to a round-bottom f l a s k , i n which has been placed the r e s t of the a n i l i n e and t o l u i d i n e together w i t h the nitrobenzene.The mixture i s heated i n an o i l bath to 100* when the i r o n , d i s s o l v e d i n two mols of HCl (to form ferrous c h l o r i d e ) i s slowly added. The f l a s k i s now connected to a r e f l u x condenser and the temperature r a i s e d gradually tol80*which i s maintained 6-8 hours. The temperature never rose above ITCT, so the mixture was heated a longer time.The melt i s f i n i s h e d when a sample withdrawn on a- g l a s s rod s o l i d i f i e d on coolding. The contents of the f l a s k are then steam-distilled,when a mixture ofjred o i l and nitrobenzene passes over.The melt i s now poured into 500 c c . b o i l i n g water,well-stirred,and 12 cc. concentrated HCl added slowly.As soon as an acid r e a c t i o n i s obtained,25 gms. s a l t are added,and the whole boiled f o r a few minutes. The aqueous s o l u t i o n which i s poured o f f contains the hyd-rochlorides of a n i l i n e and t o l u i d i n e which,as w e l l as the prev-ious d i s t i l l a t e s , i s , o n the'large scale,used again i n the manu-facture.The residue i s allowed to cool and should s d l i d i f j ' ' to a g r e e n , b r i t t l e mass.This i s then extracted w i l h 1 ^ l i t e r s of ' b o i l i n g water containing 12 cc.HCl which d i s s o l v e s the magenta. A f t e r f i l t e r i n g , t h p s o l u t i o r j i s allowed to cool,and upon stand-ing, a l i t t l e colouring matter seperates out. Using the above procedure,a dark powder was obtained at the point where a b r i t t l e mass should have appeared.The w>iole procedure was repeated,as a check,with the same results.Then i t was t r i e d again,using ferrous sulfate|in place of the ferrous chloride,and heating at l e a s t 18 hours at 170'.This time,large shining c r y s t a l s separated out on standing.Some of these were extracted with b o i l i n g water as directed ,and a very l i t t l e magenta was obtained.Yield:131.1 gms.of the large c r y s t a l s . ( c ) properties:the hydrochhorides form g l i s t e n i n g c r y s t a l s w ith a greenish r e f l e c t i o n , d i s s o l v i n g i n wl^er to a red s o l u t i o n ; dyes s i l k and wool bluish-red d i r e c t ; c o t t o n a f t e r having been mordanted with tannir^ud t a r t a r emetic. equation; o [01 0 CH<>„ 1 C,4, ^ <"> -̂'h E03IN (a ) chemicals: P l u o r s c e i n 15 gms. BrominB 33 gms. Alcohol 60 gms. (h)procedure:The f l u o r s c e i n i s placed i n a f l a s k , t h e a^cohdl added,and the bromine dropped i n slowly from a small dropping funnel.Alien h a l f the bromide has been added,the dibromide which i s formed i s i n solution;but on f u r t h e r addition of bromine, the tetrabromide separates out.After standing f o r two hoursqthe p r e c i p i t a t e i s filtered,washed f i r s t with ahcohol,then with water,and converted dimto the sodium s a l t by mixing i t with a l i t t l e hot. w a t e r , c a r e f u l l y n e u t r a l i z i n g with c a u s t i c soda (avoid-ing an excess of t h i s reagent) and evaporating to dryness on a water bath.Yield:25.6 gms f r e e acid;3.l6 gms.sodium hydroxide added,giving 24.9gras. sodium s a l t of eosin. '(c)propert i e s : f o r m s bluish-red c r y s t a l s or a brownish-red powder,dissolving i n water with a bluish-red color;dyes wool and s i l k y e llowish-red. (d) equation: •&<*st<lv ( CC-JUJZ,^ AAJUL METHYL ORANGE (a)chemicals; 5!^Sodiijim carbonate 50 cc. EulfanlLic a c i d 11 gms. Sodium n i t r i t e 5.5 gms. " • ' Concentrated HCl 7 gms. Dimethylaniline 6 gms. G l a c i a l a c e t i c a i i d 3 gms. Sodium hydroxide 7 gms. S a l t 20 gms. (b) procedure:?lace 50 cc. 5?̂  Na^COj i n a beaker,add 50 cc. wt^er,and the s u l f a n i l i c a c i d . I f the s u l f a n i l i c a c i d does not completely dissolve,add 5-10 cc. more Na^COj . I f necessary,then f i l t e r the s o l u t i o n w i t h suctionto remove the undissolved r e -sidue.Add the sodium n i t r i t e ( d i s s o l v e d i n 20 cc.water).Cddl u n t i l the temperature i s 3-5 C,then s t i r vigorously and add drop by drop a mixture i f 7 gms. HCl and 10 cc. water.Test f o r complete d i a z o t i z a t i o n w i t h Potassium iodide-starch pap«r. Add 3 gms. a c e t i c acid to 6 gms. dimethylaniline;add t h i s mijs-ture to the diazonium s a l t s o l u t i o n immediately.Allow to stand with occasional s t i r r i n g f o r 5-10 minu t e s . F i n a l l y make the s o l -u t i o n a l k a l i n e by adding a s o l u t i o n of 7 gms. sodium hydroxide i n 20 cc. water.The methyl orange separates at once;it may be made to p r e c i p i t a t e more completely by adding 20 gms. s a l t . F i l t e r with sxiction,using hardened f i l t e r paper,and c r y s t a l l i z e the impure product from hot water.Cool the hot f i l t e r e d s o l u t i p n f i l t e r w i t h suction,wash with alcohol,and f i n a l l y w i t h ether. Yield:8.6 gms. pure dye ( c ) properties:bright orange powder,dissolves In w'ater wi t h an orange color;used as i n d i c a t o r — y e l l o w i n basic s o l -u t i o n and red i n acid s o l u t i o n . (d)equation: 0 ^ — * X „mc«, »,« Ti - d ^ /V (33 H(t H^^^ - < ~ > MH- - =^ (3:> MCCH jĵ  / I4ETHYLENE BLUE (a) chemicflLls: Dimethylaniline 24 gms. Concentrited HCl 65 gms. Sodium n i t r i t e 7.1 gms. Zinc d u i t 30 gms. Sodium t h i o s u l f a t e 50 gms. Potassium dichromate 25 gms. , S u l f u r i c acid 53 gms. Sodium chromate 8 gms. ' * (b) procedure: 12 gms. dimethylar.iline are dissolved i n a mixture of 40 cc. water and 65 gms.concentrated HCl,and the so l u t i o n cooled to 12-15*C.This i s s t i r r e d mechanically,and a s o l u t i o n of 7.1 gms. sodium n i t r i t e run i n slowly ( d e l i v e r y tube beneath the surface of the l i q u i d ) keeping the temperature below 15 .The n i t r o s o compound i s reduced by adding 20 gms. zinc dust c a r e f u l l y . A d d i t i o n a l small amoimts of zinc and acid were added x m t i l the c l e a r red color of the s o l u t i o n indicated the reduction was complete.The s o l u t i o n i s now d i l u t e d with water to 500 cc. and ^solut±on0of 12 gms. dimethylaniline i n 10 cc.HCl added,and then a s o l u t i o n of 50 gms. sodium t h i o s u l f a t e i n a l i t t l e water. The mixture i s oxidized by adding a concentrated s o l u t i o n of 25 gms. Pptassium dichromate;Cain and Thorpe say to b o i l the mixture f o r two hoxirs.Since a dark blue p r e c i p i t a t e appeare'd immediately,this was not done. 53 gms. s u l f u r i c a c i d f i r s t d i l u t e d with 100 cc.water are now added,and the s o l u t i o n boiled to expel SOi^The leucoraethylene blue i s oxidized by adding 8 gms.neutral potassium chromate dissolved i n a l i : ^ t l e wat»w,and the r e s u l t i n g dye p r e c i p i t a t e d by adding s a l t . The base i s f i l t e r e d , d i s s o l v e d i n a l i t t l e b o i l i n g water to which a l i t t l e HCl has-been added,and the hydrochloride p r e c i p i t a t e d by common s a l t , f i l t e r e d , a n d dried on a porous p l a t e . ( c ) properties:dark green,or red-brovm bronzy powder,easily soluble i n water,forming a blue solution;dyes tannin-mordanted cotton blue. (d) equation: o l - i - t W /^O-dO^ I I T* AS. _3̂ >̂ A 0 ?)UUJLAA<-^ " 3 PURPURIN (a )cliemicals: A l i z a r i n 20 gms. Goncentrited H SO 200 gms. Manganese dQlxide 10 gms. (b) procedure:Into 200 gms. sulfurmc acid are mixed 20 gms. dried and powdered a l i z a r i n , w h i l e s t i r r i n g , i n an o i l bath at 100"d5iThe tepperature i s r a i s e d gradually to 150twhere i t i s maintained,until a sample dilutecyArith w a t e r , f i l t e r e d and washed with water,dissolves i n d i l u t e c a u s t i c soda with a red,not v i o l e t , color. A f t e r cooling, the melt i s mixed v/itb l ; k g . cracked i c e , the pie/hcipitate f i l t e r e d and washed with HpO* "^h* purpur-i n may be p u r i f i e d by e x t r a c t i n g with alum mixture, and then a l c o h o l . ( c ) properties :yeilow-red poAvder;the compound o^ purpurin w i t h ammonia and the a l k a l i e s are of bright red color and are soluble i n HpO. (d) equation: -BIBLIOGRAPHY 1. Adams, Roger and Johnson, John R. Elementary Laboratory Bxperiment.s i n Organi(p. Chemistry (New York:The Macmillan Company, 19457 3rd e d i t i o n . ) ^ 2. J . 0. Cain and J . P. Thorpe,- The Synthetic B y e s t u f f s ani I n t e r mediate Products (London: Charles' G r i f f i n and Company, L i m i -ted, 1923. " 6th e d i t i o n , r e v i s e d . ) 3. CaldAvell, V/illiam T. Organic Chemistry (Houghton M i f l i n Go. 1943.) 4. Mohlau, Richard imd Hans Th. Bucherer, Farbenohemisches Praktikum ( B e r l i n und L e i o z i g : Walter de Gruvter and Co. 1926.) 5. Ri e h t e r , George Holme Textbook of Qgganic Chemistry (New York: John Wiley and Sons, I n c . 1943, 2nd e d i t i o n . ) 6. 'Wertheim, S. Textbook of Organic Chemistry ( P h i l a d e l p h i a : The B l a k i s t o n Co., 1939.77 

Synthesis of Dyes

https://digitalcommons.ursinus.edu/cgi/viewcontent.cgi?article=1037&context=chem_hon

Synthesis of Dyes

Abstract

Similar works

Full text

Available Versions

Ursinus College