1-Ethynyl-4-fluorobenzene → 2-(4-Fluorophenyl)-4,5,6,7-tetrahydropyrazolo[1,5-a]pyridine

Participants

Reaction Conditions

Reaction Steps

A mixture of 2.44 g (16.5 mmol) of 4,5,6,7-tetrahydro[1,2,3]oxadiazolo[3,4-a]pyridin-8-ium 3-olate and 2.15 g (16.5 mmol) of 4-fluorophenylacetylene in 80 ml of mesitylene is stirred under argon at 165° C. for 16 h. After cooling, the reaction mixture is concentrated under reduced pressure. Purification by column chromatography on silica gel (cyclohexane/ethyl acetate) gives 888 mg (27%) of the desired product; log P(HCOOH): 2.76; 1H-NMR (MeCN-d3): 7.76 (dd, 2H), 7.11 (dd, 2H), 6.29 (s, 1H), 4.09 (dd, 2H), 2.79 (dd, 2H), 2.02 (m, 2H), 1.84 (m, 2H).

Provenance & Evidence