Synthesis of 1-amino-2-naphthalenecarboxylic acid derivatives via the intramolecular cyclization of 4-(2-cyanophenyl)-2-butenoic acid derivatives andits application to the one-pot preparation of benzo[h]quinazoline-2,4(1H,3H)-diones

The reaction of 2-(lithiomethyl)benzonitrile with 2-phenylrhio-2-alkenoic a cid derivatives in diglyme at -78 degrees C, followed by oxidation with sod ium metaperiodate in aqueous MeOH at room temperature and the subsequent el imination reaction in refluxing toluene, gave 4-(2-cyanophenyl)-2-butenoic acid derivatives in moderate-to-fair overall yields. Intramolecular cycliza tion of these products using NaH in DMF at 0 degrees C gave 1-amino-2-napht halenecarboxylic acid derivatives almost quantitatively. Successive treatme nts with an isocyanate without isolation of the aminonaphthalenecarboxylate s under reflux afforded benzo[h]quinazoline-2,4(1H,3K)-diones in moderate-t o-good yields.