Thiazoles 4-aminoiso

Simple isothiazole-4-carboxylic acids have been made from the corresponding nitriles, which are available in turn from the halogeno derivatives, or directly by the olefin route.5-Aminoiso-thiazole-4-esters and -nitriles are readily obtained by the thioamide route. The 4-acids behave normally and form acid chlorides, esters, amides, and hydrazides. In contrast to the 5-series... 

Lee and Volpp85 observed that although diazotized 5-aminoiso-thiazoles gave good yields of disulfides on treatment with thiourea, 4-aminoisothiazoles under the same conditions gave 1,2,3-thiadiazoles [Eq. (20)]. During discussion of the mechanism of this reaction, Lee... 

Amino-l,2,4-thiadiazoles are diazotized at — 10°C in phosphoric acid, and couple with naphthol to give moderate yields of diazo dyes.182,388 In their limited stability, the 3-diazonium salts resemble those of 3-aminoiso-thiazole, but differ from the more stable 1,2,4-thiadiazole- and isothiazole-5-diazonium salts a consideration of the 7t-electron densities leads to the opposite conclusion.182... 

---

See also in sourсe #XX -- [ ]

---