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Some transformations of 3‐amino‐4‐alkoxycarbonyl‐6‐hydroxy‐2 H ‐1‐benzopyran‐2‐ones. The synthesis of [1] benzopyrano[3,4‐ d ]‐[1,3]oxazine and [1] benzopyrano[3,4‐ d ]pyrimidine derivatives
Author(s) -
Fajgelj Simona,
Stanovnik Branko,
Tišler Miha
Publication year - 1990
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570270549
Subject(s) - chemistry , thiourea , derivative (finance) , benzoyl chloride , acylation , benzopyran , pyrimidine , chloride , medicinal chemistry , stereochemistry , organic chemistry , financial economics , economics , catalysis
Acylation of 4‐alkoxycarbonyl‐3‐amino‐6‐hydroxy‐2 H ‐1‐benzopyran‐2‐one derivatives 3 and 4 gave under mild conditions the O ‐substituted derivatives 5–10, N,O ‐disubstituted derivative 11 and N,N ‐disubstituted derivative 12 . The compound 4 was transformed with benzoyl chloride under more drastic conditions into 13 , a derivative of a new heterocyclic system 2‐benzopyrano[3,4‐ d ][1,3]oxazine. The derivatives of 1‐benzopyrano‐[3,4‐ d ]pyrimidine 19 and 20 were prepared either from 3 and 4 through the corresponding N ‐heteroarylformamidines 14 and 15 and N ‐heteroarylformamide oximes 17 and 18 or by cyclization of thiourea derivative 20 .