6533b85dfe1ef96bd12bdbd7

RESEARCH PRODUCT

Studies on the synthesis of heterocyclic compounds. Part IX. Action ofN,N-dimethylformamide dimethylacetal on some oximino-β-dicarbonyl compounds

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description

3-Oximino-2,4-pentanedione (1) and ethyl 2-oximino-3-oxobutanoate (6) reacted with N,N-dimethylformamide dimethylacetal (DFDA) to give 1,7-bisdimethylamino-3,5-dioxo-4-methoximinohepta-1,6-diene (4) and ethyl 5-dimethylamino-2-methoximino-3-oxo-4-pentenoate (8), respectively. When compounds 4 and 8 were treated with hydrazine hydrate, they gave O-methyldipyrazol-3(5)-ylketoxime (5) and ethyl 2-methoximino-3(5)-pyrazolylethanoate (9) together with its corresponding hydrazide 10, respectively. Upon action of DFDA on 3-oximino-2,4-pentanedione (1) at -20° an explosive crystalline product was obtained. On the other hand, the reaction of 3-acetoximino-2,4-pentanedione (11) with DFDA at -20° afforded a product which in ethanol solution, spontaneously deacetylated to give 1-dimethylamino-3,5-dioxo-4-oximinohexa-1-ene (13). The structures of all the new compounds were assigned on the basis of satisfactory analytical and spectroscopic data.