Synthesis and comparative study of reactivities of δ‐lactone, estor group and oxazinone ring in coumarin derivatives towards carbon or nitrogen nucleophiles
1990; Wiley; Volume: 8; Issue: 5 Linguagem: Inglês
10.1002/cjoc.19900080512
ISSN1614-7065
AutoresEl‐Kafrawy, Soliman, B I Baker, Mohamed Mokhtar Mohamed, El‐Kady,
Tópico(s)Synthesis and Characterization of Heterocyclic Compounds
ResumoAbstract Condensation of methyl 7‐methylcoumarin‐4‐acetate ( 2 ) with primary amines and with anthranilic acid gave 7‐methyl‐2‐oxo‐ N ‐aryl‐2 H ‐[1]‐benzopyran‐4‐acetamide ( 4a—d ) and (7), respectively. Compound 7 underwent cyclization to give 2‐(7‐methyl‐2‐oxo‐2 H ‐[1]‐benzopyran‐4‐yl)‐methyl‐4 H ‐3,1‐benzoxazin‐4‐one ( 3 ). The reaction of 3 with aromatic amines gave the corresponding quinazolone derivatives 5 which tautomerises to the thermodynamically more stable isomer 6 , whereas its reaction with Grignard reagents and aromatic aldehydes gave 8a, 8b , and 9a, 9b , respectively.
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