ON THE CHEMISTRY OF 4-AMINO-THIAZOLINE-2- THIONES .2.

6-Amino-thiazolo[4,5-c]isothiazole derivatives 4 are obtained by addit ion of hydrogen sulfide to the 4-Amino-thiazoline-5-carbonitrile 2 fol lowed by cyclooxidation of the intermediate thioamides 3. In the prese nce of sodium sulfite the hydrolysis of the 4-amino-2-methylthio-thiaz olium salts 5 derived from the title compounds 1 yields the 4-amino-th iazolin-2-ones 6. By their further hydrolysis the 2,4-dioxo-thiazolidi n-5-carboxamides 8 are formed. The 2-oxo-and 2-thioxo-thiazolo [4,5-d] pyrimidin-7-ones and -thiones available from 1 undergo ring opening by hydrolysis to give the substituted 4-amino-6-oxo- and 4-amino-6-thiox o-pyrimidine-5-thiols 15a-h and 13i-e. They have been isolated as thei r disulfides 14 or 5-alkyl derivatives i.e. the substituted 4-amino-5- alkylthiopyrimidin-6-ones and -thiones 16. In analogy, the intermediat e 6-amino-7-oxo-thiazolo[4,5-d] pyrimidin-2-thione 18 and the 7-amino- thiazolo[4,5-d]-pyrimidin-2-thione 24 derived from 1 react by ring cle avage to yield the 1,4- and 4,6-diamino-pyrimidin-5-thiole derivatives 22 and 27, respectively, isolated as their disulfides or alkylthio-de rivatives. From the pyrimidine 16b the pyrimido[5,4-b]1,4-thiazine der ivative 18 can be obtained.