Potassium Carbonate → tert-Butyl 3-ethynylazetidine-1-carboxylate

Participants

Reaction Steps

To a solution of tert-butyl 3-formylazetidine-1-carboxylate (96 g, 0.46 mol) and potassium carbonate (128 g, 0.924 mol) in methanol was added dropwise dimethyl-1-diazo-2-oxopropylphosphonate (67 g, 0.35 mol) in 1.6 L of methanol. The mixture was stirred for 2 h and filtered. The filtrate was concentrated and the residue was diluted with 800 ml of methyl-tert-butyl ether and 1 L of 5% w/w aqueous sodium bicarbonate. The layers were separated and the aqueous layer was washed with methyl-tert-butyl ether (2×500 ml). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The residue was purified by flash column chromatography to afford tert-butyl 3-ethynylazetidine-1-carboxylate.

Provenance & Evidence