Document 50aYezNzznRLMLo5opbvmQJrR

E. I. DU PONT DE NEMOURS & COMPANY KREBS PIGMENTS DEPARTMENT 256 VANDERPOOL STREET NEWARK, NEW JERSEY Serial No. Copy No. / y -T"rv * r-^y f-f' ; / ... ;\_r... v h ^ - - A i h ftft i* ;* ;?* m N. Itk^, NEWARK PLANT PIGMENT COLOR RESEARCH REPORT Period Covered: Pvo&vms Report SYim&XS Of XlQUltBEUW BY 6MOTSIC AGCO B&&I8G FAM-TOOJlDlSE-SSm^ll^IC AGIO MB PA8ft~^R-ABIIJSE- GE&O~Sm*f08IC ACID. April - Jua*j 1944 FILE: DATE: 122.41 e-zt-44 N37947 Serial Ho. KH-44-54 Copy Ho. / Copy to* #1 - Humerical Pile , 2 - Research Office (122*41) 3 - Library Pile (122*41) 4 - imperial Chemical Industries, Ltd. 5-it n ^^ n n n it 7 - Mr. C. H. Rupprecht, Wilmington (ICI File)&c'4K v 0~ NEWARK PLANT PIGMENT COLOR RESEARCH REPORT Progress Report Title* SXBTHSSIS OP INTERMEDIATES BX SULFURIC ACID BAKING PARA-TOLUIDINE-META-SOLFOBIC ACID AND PARA-CHLOR-ABILIHEORTHO-SOLFOHIC ACID. Period Covered* April - June, 1944 SUBMITTED BX* S'* H. Cooper APPROVED BY: DATE SUBMITTED: 8-21-44 DATE ISSUED: 8-29-44 DUP050149778 -2' mnwmm* The well known sulfaailic acid rearrangement (l.e. the synthesis of aoiline-para-sulfonic sold from aniline by sulfuric add baking) is used commercially to prepare several intermediates of importance to the lake industry* Among these are para-toluldlnemeta-sulfdSiie acid (^Idthasol* Rublne G intermediate) and p&ra-chloranlltne-ortho-sulfonic add (^Lithoso^ Scarlet SXL intermediate)* The former is synthesised from para-toluidine; the latter from parachlor-anillne. The comparative simplicity of these manufacturing processes* has led to the consideration of their possible introduction at Newark, As a preliminary it was necessary to obtain some information on the laboratory preparations, which study constitutes the subject of the present report* I It has been shown that both para-tolsfilll|toHBeta-sulfonic add (PTMSA) and para-chlorSaniline-ortho-sulfonie add (PCAOSA) can be readily prepared in good yield by a sulfuric add baking synthesis* Although only a limited amount of laboratory study was devoted to these preparations, nevertheless the yields obtained were quite encouraging* For PTMSA a maximum yield of SB*5$ of theory was realized* for PCAOSA a yield of 70.5$ was attained. It is reasonable to expect that a limited variable study, including investigation of the baking temperature and the duration of baking, may disclose condi tions leading to still higher yields. Ho further laboratory study of these specific syntheses is contemplated at the present time. Any equipment installation suitable for the manufacture of PTMSA would also be suitable for the preparation of other intermediates by the sulfuric add baking synthesis. At the present time the two intermediates covered In this report and nLithosoln Red 2B Acid ere the only ones synthesized by this method which are currently used at Newark. However, it is possible to prepare many other products, some of which are definitely speculative and the merit of which has yet to be demonstrated, and It is planned to high spot such possibilities. For this purpose cheap substituted aniline compounds, which on theo retical grounds should lead themselves to conversion by the sulfanilic add type of rearrangement, are being Investigated, This speculative study will be reported elsewhere. mm&.Pi.cpBsm*. The preparation of PTMSA from para-toluidine by treatment with concentrated sulfuric acid and subsequent baking is frequently mentioned in the early literature (Ref. l), but the directions for the preparation are none too explicit. Two attempts to prepare PTMSA in accordance with these vague directions led to only limited success, the maximum yield obtained being 39.4$ of theory. DUP050149779 ................. dbSefiX inves... to assure maximum yields in' this (Ref. )** By foXldwing-bbe ' possible to iiigffhs yielis -- fail* ia-aat)et?3 WQrfe. i,t vwrcii of m : rfeUigiTi* the conditions neeassary aesa' was made by Bttber a of Bober" it was found to $63" la th oooo of ' atr&ted that too stages inf yields; these mm I* fb formation of the aeid sulfate from the: free base* 2* fbe baking of the acid sulfate to effect- the re* arrangement to the: amine -saifoaie acid. In the early literature it was apparently common practice to form the acid sulfate -by treatment* of the amine with concentrated sulfuric .acid, is is well known, it is extremely difficult to obtain a uniform reaction by such a procedure. Buber recognised that the ncMpifoimity of this treatment led to complications, such as forma* tion of disulfonic adds and other by-products, in the subsequent baking stage of the synthesis. However, by using diluted sulfuric add - Buber recommends 10% in most oases - it is possible to prepare the amine add sulfate in aqueous solution at high temperature. Even though this crystallises on cooling, nevertheless a uniform product has been assured by its preparation In solution* Since for every mole of amine acid sulfate rearranged to the amine sulfonic add, one mole of water is liberated, and since this reaction is reversible, Buber recognized the value of working at reduced pressure during the baking. For similar reasons the dura tion of the baking eyele may be reduced when operating at reduced pressure., In all cases but one, the PTHSA and PCAGSA made in the laboratorywsna purified by extraction with aqueous caustic soda and subsequent precipitation by acidification. In this manner little trouble was eaeoBBBtmad. in removing the hard reaction mass from the baking process. In the one case where an attempt was made to obtain the PfMSA: in crude fora (i.e* as obtained directly from the baking process), considerable trouble was encountered in reacting the hard reaction mass from the enamel pan In which the baking had been con ducted. In this case considerable mechanical force, such as hammering of the bottom of the enamel pan, was necessary. It is obvious that the removal of the crude intermediate constitutes a problem for serious consideration by competent engineers in the event that we should decide to manufacture the intermediate and retain it In crude form. Another possibility is to extract the intermediate with aqueous caustic soda and to retain it as a stock solution of the DU P050149780 -4solution for 82 days showed a gals is weight of only 0*06#* At the end of this period the appearance of the iron was satisfactory, evi dence of corrosion appearing only at the freshly cut surfaces. It Is therefore safe to assume that a storage tank made of wrought iron would he satisfactory for retention of a stock solution of the sodium salt of PtMSA. Purified laboratory PfhSA and the sodium salt stock solu tion were found to he satisfactory for the manufacture of *Duol* Carmine (Bf~443MS} by the K3J74 (direct laklng) process or suitable modifications thereof, the one'laboratory preparation of crude PTMSA (nitrite value 65.7#) did not give satisfactory results in this process. However, it seems reasonable to assumtgttftif had suitable ; pH adjustments been made at the crucial points, the crude intermediate! could have bees made to work satisfactorily. the PCAOSA (Scarlet 2TL Intermediate) gave esaainently satisfactory Watehung Red BX, HE-4S8-D, by laboratory raw material tests* DU P050149781 AgMMGOt 196 Balfuric Add oc. Goe*aeld, * Sp*gr. * 1 *i4l 75 ec water 214 grams para-toluidlne 200 grams caustic soda 1000 ce. of water 1000 ce* of water 10 grams Borlte 10 grams Filtered! 176 grams sulfuric acid, 100$ (as a 50$ solution) ":tm .to. ' ' -Vv"'- with ,^felrrig*;' tea#''to ; "^V1r* |df with ftilling during , 4^*^ s^in^utes Stir 5 minutes after addition it complete* . W0& the aoliiti*: of' fiia4olili6iae alia sulfate into ' a jmmaotti-fta^' Seat on , oil MMhftt 210*2506G. for 4 tef* at a pressure of 50-90 millimeters of mercury* Cool and extract with ** -f dissolved 1 at the boil* Use additional for washing* Steam distill until the distillate is no longer cloudy* Boll the solution remaining in the distillation flask with for 15 minutes* Filter through steam-jacketed Buchner funnels* Md with stirring A fin cream-colored precipitate is obtained* Filter, wash, and dry at 140F, DUP050149782 Preparation of PCAQSA la very similar to the forpreparation of PT1SSA. However, because of the lower solubility of the acid sulfate of para-chlor-anillne, suitable notifications in the solution stage must be mate* In addition definite evidence was obtained that longer baking is necessary, IQ hours at 210~230C. being required to attain a yield of 70*5$. Notebook 1102, Ixpts. 1 to 6 incl. gSAQ^A $sa,thesis. Notebook 1102, Expts. 7 & 3. 31-8,4.zJBLXam Notebook 1093, Expts, 13 & 25. Notebook 936, Expts. 34 & 35. REFERENCES8 1. Neville, Winthe Richter - Ann. Wynne, Bruce - ioe. 21> 738 (1898) 2. Huber - Helv, Chin, Act 1372-83 (1932) DUP050149783