Synthesen von Heterocyclen, CCVII Mesoionische Pyrimidine und Thiazine / Syntheses of Heterocycles, CCVII Mesoionic Pyrimidines and Thiazines

Abstract

Benzanilidoxim-benzylether reacts with C 3 O 2 in chlorobenzene yielding the pyrimidiniumolat 2. S-Alkyl-N,N′-diaryl-isoureas can be converted with C 3 O 2 to 2-alkylthio-l-pyrimidinium-4-olates (3a-f). 2-Ethylthio-2-pyrazolin gives 8-ethyl-7-oxo-2,3-dihydro-7 H-imidazo[2,3-b][1,3]-thiazin-8-ium-5-olat (5a). Starting with O-alkyl-N,N′-disubstituted isoureas and C 3 O 2 the corresponding 1-pyrimidinium-4-olates (6a—d) are obtained.