Ethyl diazoacetate → trans-ethyl 2-(6-chloro-1-trityl-1H-pyrazolo[4,3-c]pyridin-3-yl)cyclopropanecarboxylate

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Reaction Conditions

Reaction Steps

A mixture of 6-chloro-1-trityl-3-vinyl-1H-pyrazolo[4,3-c]pyridine (100 mg, 0.237 mmol, derived from 3a and vinylboronic acid pinacol ester as described in Scheme 1, Step 3) in toluene (2 ml) under nitrogen was treated with ethyl diazoacetate (0.074 ml, 0.711 mmol) and heated at 100° C. overnight to give a yellow solution. The reaction was cooled to room temperature and then diluted with aqueous sodium hydrogen carbonate and dichloromethane. The organic layer was concentrated and purified by column chromatography on silica gel (24 g, eluting with 0-20% EtOAc/hexanes) to give two products: trans-ethyl 2-(6-chloro-1-trityl-1H-pyrazolo[4,3-c]pyridin-3-yl)cyclopropanecarboxylate (77 mg, 64% yield) and cis-ethyl 2-(6-chloro-1-trityl-1H-pyrazolo[4,3-c]pyridin-3-yl)cyclopropanecarboxylate (37 mg, 31% yield). MS ESI calc'd. for C31H26ClIN3O2[M+1]+ 508, found 508.

Provenance & Evidence