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Azo dyes from 2-amino-1,3,4-thiodiazole
Short communications Talanta. 1967, Vol. 14. p. 123.
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123
Printed in Northern Ireland
Azo dyes from 2-amino-1,3,44hiodiazole (Received 7 October 1966. Accepted 9 October 1966) hhx~0-1,3,4-~~1o~~o~~ is similar to 2-aminothiazole, in that it can be diazotized with nitrous acid.’ The calorimetric properties of the thiodiazolylazo dyes have not been studied except for the b-naphthol compound which has been used as an acid-base indicator.’ Substituted thiodiazolylazo compounds have also been investigated both academically and as commercial dyestuffs.‘+
EXPERIMENTAL Preparation of reagents which Thiosemicarbazide was treated with formic acid to give Zfo rmamido-1,3,4-thiodiazole,s was more was then heated with hydrochloric acid to produce. the amine. 2-Amino-1,3,4-thiodiazole water-soluble than 2-aminothiazole but on diazotization gave lower yields of the dyestuffs. Thiodiazolylazo dyes from resorcinol (TdAR),p-cresol (TdApC) and &naphthol (TdANB) were prepared. RESULTS
AND
DISCUSSION
TdAR is a yellow dye, orange in alkali, which gives red-brown complexes with many metal ions. TdApC was very similar to thiazolylazo-p-cresol (TApC) giving colour changes from yellow to blue on chelation, whereas TdANj3 was paler than thiazolylazo+naphthol (TAN/?). These three thiodiazolylazo dyes all gave greenish complexes with iron and ruthenium. TdAR, TdANp, and TdApC were not obtained in a very pure state, but were definitely less sensitive towards all metals than the thiazolylazo dyes. This is probably due to the lower basicity of the nitrogen atom of the thiodiazole ring. In a similar manner, the extra nitrogen atom present in 8-hydroxycinnoline causes it to form weaker complexes than I-hydroxyquinoline .* Since the thiodiazolylazo dyes also produce duller colour changes than their thiazole and triazole analogues, they were inferior in all respects. Department of Inorganic Chemistry F.H. POLLARDa G. NICKLESS@ School of Chemistry T.J. ,!bMUELSON The University Bristol 8 England Smmnary-Thiodiazolyazo dyes from resorcinol, p-cresol and /?naphthol have been prepared. They are inferior to their thiazole and triazole analogues in their colour-forming reactions with metal ions. R&urn&On a p&par6 les colorants thiodiazolylazo du resorcinol, du pcresol et du b-naphtol. Dans leurs reactions color&s avec les ions metalliques, ils sont inferieurs a leurs analogues thiazoliques et triazoliques. Zusammenfassung-Es wurden Thiodiazolylazofarbstoffe von Resorcin, pKreso1 und /I-Naphthol hergestellt. Sie sind in ihren farbbildenden Reaktionen mit Metallionen ihren Thiazol- und Triazolanalogen unterlegen. REFERENCES 1. R. Stolle and K. Fehrenbach, J. Prakt. Chem., 1929,122,289; Chem. Abstr., 1930,24,114. 2. D. I. Kurbatov and N. F. Kazarinova, Izv. Sibirsk Otd. Akad. Nauk SSSR, 1958, 8, 94; C/rem: Abstr., 1959, 53, 9886. 3. J. Goerdeler and K. Deselaers, Chem. Ber., 1958,91, 1025; Chem. Abstr., 1960, 54,454s. 4. G. Lange, Ger. Patent, 1150468 (1963); Chem. Abstr., 1964,60,8166. 5. S. Ban, J. Pharm. Sot. Japan, 1954,74,695; Chem. Abstr., 1954,48,10741. 6. E. J. Alford, H. Irving, H. S. Marsh and K. Schofield, J. Chem. Sot., 1952, 300.
Per@mxt
Press Ltd.
123
Printed in Northern Ireland
Azo dyes from 2-amino-1,3,44hiodiazole (Received 7 October 1966. Accepted 9 October 1966) hhx~0-1,3,4-~~1o~~o~~ is similar to 2-aminothiazole, in that it can be diazotized with nitrous acid.’ The calorimetric properties of the thiodiazolylazo dyes have not been studied except for the b-naphthol compound which has been used as an acid-base indicator.’ Substituted thiodiazolylazo compounds have also been investigated both academically and as commercial dyestuffs.‘+
EXPERIMENTAL Preparation of reagents which Thiosemicarbazide was treated with formic acid to give Zfo rmamido-1,3,4-thiodiazole,s was more was then heated with hydrochloric acid to produce. the amine. 2-Amino-1,3,4-thiodiazole water-soluble than 2-aminothiazole but on diazotization gave lower yields of the dyestuffs. Thiodiazolylazo dyes from resorcinol (TdAR),p-cresol (TdApC) and &naphthol (TdANB) were prepared. RESULTS
AND
DISCUSSION
TdAR is a yellow dye, orange in alkali, which gives red-brown complexes with many metal ions. TdApC was very similar to thiazolylazo-p-cresol (TApC) giving colour changes from yellow to blue on chelation, whereas TdANj3 was paler than thiazolylazo+naphthol (TAN/?). These three thiodiazolylazo dyes all gave greenish complexes with iron and ruthenium. TdAR, TdANp, and TdApC were not obtained in a very pure state, but were definitely less sensitive towards all metals than the thiazolylazo dyes. This is probably due to the lower basicity of the nitrogen atom of the thiodiazole ring. In a similar manner, the extra nitrogen atom present in 8-hydroxycinnoline causes it to form weaker complexes than I-hydroxyquinoline .* Since the thiodiazolylazo dyes also produce duller colour changes than their thiazole and triazole analogues, they were inferior in all respects. Department of Inorganic Chemistry F.H. POLLARDa G. NICKLESS@ School of Chemistry T.J. ,!bMUELSON The University Bristol 8 England Smmnary-Thiodiazolyazo dyes from resorcinol, p-cresol and /?naphthol have been prepared. They are inferior to their thiazole and triazole analogues in their colour-forming reactions with metal ions. R&urn&On a p&par6 les colorants thiodiazolylazo du resorcinol, du pcresol et du b-naphtol. Dans leurs reactions color&s avec les ions metalliques, ils sont inferieurs a leurs analogues thiazoliques et triazoliques. Zusammenfassung-Es wurden Thiodiazolylazofarbstoffe von Resorcin, pKreso1 und /I-Naphthol hergestellt. Sie sind in ihren farbbildenden Reaktionen mit Metallionen ihren Thiazol- und Triazolanalogen unterlegen. REFERENCES 1. R. Stolle and K. Fehrenbach, J. Prakt. Chem., 1929,122,289; Chem. Abstr., 1930,24,114. 2. D. I. Kurbatov and N. F. Kazarinova, Izv. Sibirsk Otd. Akad. Nauk SSSR, 1958, 8, 94; C/rem: Abstr., 1959, 53, 9886. 3. J. Goerdeler and K. Deselaers, Chem. Ber., 1958,91, 1025; Chem. Abstr., 1960, 54,454s. 4. G. Lange, Ger. Patent, 1150468 (1963); Chem. Abstr., 1964,60,8166. 5. S. Ban, J. Pharm. Sot. Japan, 1954,74,695; Chem. Abstr., 1954,48,10741. 6. E. J. Alford, H. Irving, H. S. Marsh and K. Schofield, J. Chem. Sot., 1952, 300.