FUROPYRIDINES .15. SYNTHESIS AND PROPERTIES OF ETHYL 2-(3-FURO[2,3-B]PYRIDYL)ACETATE, 2-(3-FURO[3,2-B]PYRIDYL)ACETATE, 2-(3-FURO[2,3-C]PYRIDYL)ACETATE AND 2-(3-FURO[3,2-C]PYRIDYL)ACETATE

Ethyl 2-(3-furopyridyl)acetates 10a-d were synthesized from furopyridin-3(2H)-ones 4a-d by the Wittig-Horner reaction with diethyl cyanomethylphosphonate, hydrolysis and the subsequent esterification. Reaction of compounds 10a-d with lithium diisopropylamide (LDA) gave the corresponding methylenelithiated intermediate, and the subsequent reaction with benzaldehyde, acetone and iodomethane afforded the methylene-alkylated product respectively, while N,N-dimethylacetamide did not give any reaction product. The 2-position of 10a, b and d is alkylated by the lithiation with excess of LDA and the successive reaction with an electrophile.