反应详情

Reaction Scheme X illustrates an alternative preparation of the 1,6-naphthyridin-5(6H)-one compounds. In this Scheme, Weinreb amide VIII-2 is reacted with an aryl lithium reagent, generated from aryl bromide X-1, in which R is a protected or masked amino methyl derivative such as 1-(1-azido-1-methylethyl), to give ketone X-2. Condensation of this ketone with tert-butyl(2-chloro-3-formylpyridin-4-yl)carbamate in the presence of sodium methoxide, gives the 1,6-naphthyridine X-3. Deprotection or unmasking of the amine, in this case by palladium catalyzed reduction with hydrogen provides amine X-4. Treatment of X-4 with hydrochloric acid gives 1,6-naphthyridin-5(6H)-one X-5.