Potassium Carbonate → Tert-butyl 4-ethynyl-4-methylpiperidine-1-carboxylate

Participants

Reaction Steps

K2CO3 (5.25 g) and 4-formyl-4-methyl-piperidine-1-carboxylic acid tert-butyl ester (5.23 g) are added to an ice cold mixture of dimethyl (1-diazo-2-oxopropyl)-phosphonate (5.50 g), molecular sieves (2 g), and methanol (30 mL). The mixture is stirred in the cooling bath for 30 min and then at room temperature overnight. The mixture is filtered and aqueous NH4Cl solution is added to the filtrate. The resulting mixture is extracted with dichloromethane and the combined extracts are concentrated. The residue is chromatographed on silica gel (cyclohexane/ethyl acetate 4:1→1:1) to give the title compound.

Provenance & Evidence