Synthesis and properties of 3-hydroxy-1,10-dioxo-5,10-dihydro-1H-pyrido[2,1-b]quinazoline-2-carbonitri le

Article abstract of DOI:10.1002/ardp.19843171003

Anthranilic acid reacts with 2-chloro-5-cyano-4-hydroxypyrid-6-one (3) in glacial acetic acid to yield 3-hydroxy-1,10-dioxo-5,10-dihydro-1H-pyrido[2,1-b]quinazoline-2-carbonitri le (4). When the reaction is carried out in DMF under Ullmann conditions, 2-(dimethylamino)-5-cyano-4-hydroxypyrid-6-one (5) forms as a by-product. The methylation of 3 with diazomethane affords 2-chloro-5-cyano-2-methoxy-N-methylpyrid-6-one (9) and 2-chloro-5-cyano-4,6-dimethoxypyridine (10). Under similar conditions compound 4 undergoes an esterifying ring cleavage to furnish methyl 2-(5-cyano-4,6-dimethoxypyrid-2-ylamino)benzoate (7).