Conversion of 3,7-Dialkoxy-4H,8H-benzo[l,2-c:4,5-c']diisoxazole-4,8-dione into new heterocyclic systems

Treatment of 1a or 1b with concentrated acids yielded the acid 3 , with alkali hydrogen carbonates the sodium salt 7 and the potassium salt 8 ; by reacting with phosphorus pentachloride the vinylogous acid chloride 9 was isolated. Reactions of 9 with amines such as N-nucleophiles led to the corresponding amides 10, 11, 14, 15 , and with alcohols such as O-nucleophiles to the corresponding alkoxyderivatives 16a, 16b , which are isomeric compounds to 1a, 1b and 2a, 2b.