FUROPYRIDINES .15. SYNTHESIS AND PROPERTIES OF ETHYL 2-(3-FURO[2,3-B]PYRIDYL), 2-(3-FURO[3,2-B]PYRIDYL), 2-(3-FURO[2,3-C]PYRIDYL) AND 2-(3-FURO[3,2-C]PYRIDYL)ACETATE
S. Shiotani et al., FUROPYRIDINES .15. SYNTHESIS AND PROPERTIES OF ETHYL 2-(3-FURO[2,3-B]PYRIDYL), 2-(3-FURO[3,2-B]PYRIDYL), 2-(3-FURO[2,3-C]PYRIDYL) AND 2-(3-FURO[3,2-C]PYRIDYL)ACETATE, Journal of heterocyclic chemistry, 32(1), 1995, pp. 129-139
Ethyl 2-(3-furopyridyl)acetates 10a-d were synthesized from furopyridi
n-3(2H)-ones 4a-d by the Wittig-Horner reaction with diethyl cyanometh
ylphosphonate, hydrolysis and the subsequent esterification. Reaction
of compounds 10a-d with lithium diisopropylamide (LDA) gave the corres
ponding methylenelithiated intermediate, and the subsequent reaction w
ith benzaldehyde, acetone and iodomethane afforded the methylene-alkyl
ated product respectively, while N,N-dimethylacetamide did not give an
y 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 ele
ctrophile.