Kiss, József

Vinkler, Elemér

English

Kiss József

Vinkler Elemér

University of Szeged

75-References. 1. J. Bjerrum; Metal Ammine Formation an Aqueous Solution Copenhagen (1941), 2. H'. Dirking: Z. 'anorg.' allg. Chem. 223. (1937) 321. 3. J. Gr oh; Z. anorg. allg. Chem. 146. (1927) 305. 166. (1929) 237. 4. A. Hantzsch: Z. anorg. allg. Chem. 159. (1927) 2 91. 5. F. G. Donnan and H. Bassett: J. Chem. Soc. London 81. (1902) 939. 6. A. Kiss and M. Gerendás: Z. physik. Chem. A. 180. (1937) 117. A. Kiss--and M. Richter: Z. physik. Chem. A . 187. (1940) 211. 7. W. R. Brode; J. Amer. Chem. Soc. 53. (1931) 2457. 8. A. Kiss: Acta Chem. mineral, physica Univ. Szeged. 7. (1939) 119. • / • Institute of Organic Chemistry (Director: Prof. G. Fodor) Institute of Pharmaceutical Chemistry (Director: Prof. D. Kőszegi) of the University of Szeged i Hungary) The Reaction of Aryl-thio-glycolic acid chlorides with sodium azide B y JOZSEF K i s s a n d ELEMER VINKLER The reaction between acid chlorides and sodiumazide is known since a long time in the literature.1 The formed" azidie decomposes^ readily with evolution of nitrogen and rearranges into the corres-ponding isocyanaite. This raction proceeds very easily particuliarly in the case of the aliphatic acid-azides. The isocyanate compounds react readily, e. g. with water and yield primary, ammo-compounds on evolving carbon dioxyde. According to the as yet not published results of E. Vinkler the phenyl-thio-glycolic acid azide (II. a.) recovered at the reaction between phenyl-thio-glycolic acid chloride (I. a;.) and sodium azide-is spontaneously converted into phenyl thiomethyl isocyanate (III. a,). This compound1 could be separated in the form1 of a solution Avhich can readily be distilled. In consequence of its great'- reacti-vity it reacts with various agents, e. g. with water and is converted into N, N'-bis-(phenyl-thiomethyl)-carbamide (V. a.). If it is allowed to stand in an open vessel for several days the isocyanate yields, the same carbamide derivative. The purpose of this paper is to study to what am extent the various aryl radicals exert an influence on the reactivity of the-isocyanate . .synthesized from aryl-thiomethyl-glycolic chlorides. In the following experiments the conversion of /3-naphtyl- and p-tolyl-thio glycolic azid which had formed as intermediates; was investigated. To enable the synthesis of these substances p-methyl-: - thiophenol2 and thio-/?-naphtol were prepared from the suitable sulfochloride in phosphorus acid through reduction with potassium iodide in the presence of red phosphorus. This method enabled the preparation of thio-^-naphtol' in a. far better yield and under far simpler experimental conditions than. 76 the procedure described in the literature.3 The thiophenol dQrivati-^ ves were submitted in the usual manner to a basic reaction with monochloro-acetic acid" and the p-tolyl-respectively /3-naphtyl--thio-glycolic acid was converted with thionyl chloride, or phos-phorus trichloride into the suitable acid chloride. Both thio-glycolic acid derivatives were. made to react in abs. toluene with sodium azide, previously activated by hydrazine hydrate, under the con-ditions described in the experimental1 part. In analogous manner to that of the isolation of phenyl deri-vatives the isolation of isocyanates was also attempted. These expe-riments failed as the crystals separating out from te abs. toluene solution, on cooling, did not exhibit the expected properties of iso-cyanates. They did not react with water, alcohol etc. According to their behaviour and to their analytical data the compounds obtained. ( in this way proved, to be carbamide derivatives. The intermediate p-tolyl-, resp. /?-naphtyl-thio:methyl isocyanate (III. b., III . c, resp) is converted probably by the moisture of the air into p-tolyl-, resp. ¿8-naphtyl-thiomethylamine. (IV. a. and b.) which in turn' reacts t immediately with the simultaneously present isocyanate yielding N, N'-bis/p-tolyl-, resp. /?-na,phtyl-!thiomethyl carbamide (V. b. and c.). A similar phenomenon was reported by Goldstein and Viaud' in the case of 5,8-dichioro-2-naphtazide. The formed isocyanate reacts readily with the moisture of the air yielding bis-5,8-dichloro--2-naphtyl carbamide. The authors mentioned above d'id not either succeed in separating the corresponding isocyanate, their experi-mental results were analogous to ours. R - S - C H 2 - C / Q + N a N 3 — " R - S - C H 2 - C ^ N 3 — v I. • II. — > R - S — C H 2 - N = C = O t j - ^ R - S - C H 2 - N H 2 - f c o 2 H2U III. VI. III. + IV. — - R - S - C H 2 - N H - C O - N H - C H 2 - S - R V. R = a ) C 6 H 6 - ; b) ( p ) C H 3 - C 6 H 6 - ; c ) 0 ? ) - C l o H 7 . On comparing the experimental results mentioned above the . ' question arises as to the caiuse of the enchanced reactivity of the p-tolyl- and /3-naphtyl-thiomethyl isocyanate as compared with that of the analogous phenyl-thiomethyl isocyanates. The greater re-activity of the former can probably be attributed to the less sym-metrical distribution of the electrons on the radical of the p-tolyl-, resp. /?-naphty] than in the case of benzene and to the fact of this ~ asymmetric being transferable to the radical1 attached to the thio-' methyl-isocyanate group, thus promoting its polarisation and the-reby increasing ife reactivity. In the course of further investigations the work described above will be continued and extended towards the accurate deter-mination of the differences between the reaction rates of the un-77 substituted and the substituted phenyl-thiomethyl isocyanates on yielding earbamides. Furthermore, the studies will also be persued in the direction of how far the position of the substitu^nts influen-cing in various manners the reactivity, and thus the distribution of the electrons on the aromatic ring, modifies the above described reaction, resp. reaction rate of the thiomethyl isocyanate group. Experimental. Thio [3-naphtol. lOg naphtalir.e 15-!sulfochloride purified in ether is ground with 8.5 g potas-sium idodide and 3.2 g red phosphorus and then mixed with 42 ml of syrupy phos-phorus acid in a glass bulb and kept boiling through an asbestos wire gauze with reflux. Shortly after the boiling sets in a vigorous reaction is smarted the wall of the reflux condenser is coa'ted with iodine which is rindsed off with 10 ml of alcohol. After boiling it for 10 hours it is cooled and subsequently extracted with 100 ml of ether, the ethereal extract is shaken with 100 ml N sodium hydroxyde and then the mercaptaii liberated with hydro-chloric acid. Finally the thio B-napthoI is again extracted. The ether is distilled off in vacuo yielding pale yellow crys-tals. M. p. 81°, yield 6.6 g (94.3%). fi-naptyl-fhioglycolic chloride. 7.8 g of recrystallized naphtyl-thio-glycolic acid is heated with 1.8 g phos-phorus trichloride for an hour at 60—70°, and then after standing for an hour extracted with 25 ml ether. The solvent is removed from the ethereal solution in vacuo, A colourless transparent syrup is obtained which desomposes on being distilled in vacuo. For the following reactions purified by extraction in ether is used. The reaction of B-naphtyt-ithioglycolic chloride with sodium azide. 12 g JJ-naphtyl-thioglicolic chloride is dissolved in 40 ml abs tolune and 4.1 g of sodium azide added which had been activated with hydrazinehydraiie.0 The reaction mixture instantaneously warms up to 80° and gas is evolved. It is- heated on the water-Ibath for an hour and then filtered hot. The precipitate is rewashed with 30 ml hot toluene. On standing for a few hours the separation of the crystals which s'iarts immediately the solution cools down is completed. The filtered crystals are recrystallized from toluene, or aqueous alcohol. Fine white needles. M. p. 142—144°. * Analysis: Calcd. for C23H20ONaS2: C, 74 14 ; H, 5.41 ; Fond C, 73 .88; H, 5.26. p-Tolyl-thioglycolic chloride. 7.3 g of p-iolyl-ihioglicolic acid purified by recrystallization is added to 2 g phosphorus trichloride and kept for about an h'our'i at 60—70°' till the evolution of hydrochloric aicid ceases. It is allowed to stand for an hour and tljen extracted with 25 ml of ether. After distilling off the ether in vacuo a colourless oil is obtained whicht is used without further purification. The reaction of p-tolyt-thioglycolic chloride with sodium azide. .7.1 g acid chloride is dissolved in 25 ml abs. tolune, 3.3 g sodium azide is added which was previously, activated by hydrazine hydrate. A significant rise 78 / in temperature can be observed. It is heated on the water-ibath at 80° for an hour. The toluic solution is filtered hot, the precipitate remaining on the filter is washed •with 20 ml of hot toluene. On cooling of the toluic solution white, needle-shaped crystals separate out. After filtering off .the crystals (3.3 g),. the toluene solution is evaporated down to 20 ml in vacuo. The crystals which separated after cooling are again filtered off (1.6 g). M, p. 124—126°. Both crystal hulks are recrystallized together from toluene. M. p. 134°. Analysis: Caicd. for C17H20ON2S2: C, 61 .39 ; H, 6 03 Found C, 61.61 ; H, 6.21. Summary. The reaction between /3-naphtyl- and p-tolyl-thioglyeolic chio-'ri.de and sodium azide was investigated. The isocyanate, which for-med during the reaction could not; in contrast to the' analogous phenyl derivative, be separated, but was converted by the moisture of the air into aryl-thiomethylaimine; yielding with the simulta-neously present isocyanate the corresponding carbamide derivative. In memoria. We conform to a pious duty in recalling^ A he memory of our most efficient collaborator Ferenc May, who took^ part in the expe-rimental work until his death caused by tragic consequences of the I I . world war. N References. 1. Naegeli et al. : Helv. Chim. Acta, 12 (1929) 227. , 2. Karrer and Schmidt: Helv. Chim. Acta. 22, (1939) 609. 3. Friedlander es Woroshzow: Liebigs Ann. Chem. 388, 14. 4. Billeter; Ber. deutsch. Chem. Ges.S, 463. 5. H. Goldstein and P. Viaud; Helv. Chim. Acta. 27, (1944) 883. 6. Nelles: Ber. deutsch. Chem. Ges. 65, (1932) 1345. s 

The reaction of aryl-thio-glycolic acid chlorides with sodium azide

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The Reaction of Aryl-thio-glycolic acid chlorides with sodium azide

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