反应详情

Condensation of ethylglyoxalate with 4-methoxyphenyl hydrazine and chlorination with NCS afforded (4-Methoxy-phenyl)-chlorohydrazono]-acetic acid ethyl ester. Separately d-valerolactam was dichlorinated with PCl5 and treated with morpholine at reflux to afford 3-Morpholin-4-yl-5,6-dihydro-1H-pyridin-2-one. [3+2] cycloaddition of the chlorohydrazone with the morpholine dihydropyridinone obtained above in refluxing toluene and triethylamine afforded the key intermediate 1-(4-Methoxy-phenyl)-7-oxo-4,5,6,7-tetrahydro-1H-pyrazolo[3,4-c]pyridine-3-carboxylic acid ethyl ester. Alkylation (with 4-bromo-butyrylacetate) followed by deprotection of the acetate group as outlined outlined in Example 32, and amidation of the ester with ammonia afforded the desired compound. Mass Spec 357.3(M−H)−.

1. temperatureat reflux