Phosphorylation and amine-induced dephosphorylation of 4-chlorocoumarin-3-carboxaldehyde and 4-chloro-3-(beta, beta-dicyanoethenylidene)coumarin

摘要

4-Chlorocoumarin-3-carboxaldehyde (1) and 4-chloro-3-(beta,beta-dicyanoethenylidene)coumarin (2) produce their respective 1:1 phosphonate adducts (5a-c) and (6a-c) upon reaction with the appropriate dialkylphosphonates (3a-c). Compounds 5 undergo dechlorination and dephosphorylation upon reaction with certain primary aliphatic amines to yield 9 (or 10) according to the nature of the amine used. Compounds 1 and 2 undergo dechlorination through reaction with hexamethyl-phosphorustriamide 4 to give the respective 4-dimethylamino-derivatives (11a and 11b). Structural reasonings for the new compounds are based on compatible analytical and spectroscopic measurements. The mechanism for formation of compounds 11 also is discussed. [References: 19]