DIALKYL FORMYL-1 METHYLPHOSPHONATES α-FONCTIONNELS-II. PREPARATION PAR VOIE THERMIQUE ET TRANSFORMATION EN HETEROCYCLES α-PHOSPHONIQUES

Article abstract of DOI:10.1016/S0040-4020(01)96436-1

The thermal condensation of functional phosphonates bearing strongly withdrawing groups (RO)2P(O)CH2Z 1 with dimethylformamide dimethyl acetal gives corresponding β-functional, β-phosphonic enamines (RO)2P(O)C(Z)=CHNMe2 2.Acid or basic hydrolysis of the enamines frequently gives the free aldehyde (RO)2P(O)CH(Z)-CHO 3.We show that the enamines can be used with success for the synthesis of heterocycles like, pyrazoles 4, pyrimidines 5, benzodiazepine 6 or indole 7, all of them substituted with a phosphonate group.