1.2.4- Triazolo quinazolin-5-ones synthesis

In one synthesis [76JAP(K)76100098], l,2,4-triazolo[4,3-a]quinazolines (304) were prepared from 1,2,4-triazole precursors when 2-(l, 2,4-triazol-3-yl)benzophenones (303, LG = OR,SH, or SR) were cyclized with ammonia. 

Synthesis of 9-substituted tetrahydroazepinopurines as asmarine analogs has been described <03T6493>. In relation to adenosine receptor antagonists, new derivatives of pyrazolo[4,3-c][l,2,4]triazolo[l,5-c]pyrimidines have been synthesized <03IMC1229, 4287>. A one-pot synthesis of l,2,4-triazolo[l,5-c]quinazoline thiones 65, consisting of a domino cyclization of 2-isothiocyanatobenzonitrile 63 with hydrazides 64 has been published <03EJO182>. 

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