Methoxymethyl-triphenylphosphonium chloride → 1-(4-Chlorocinnamyl)-4-[1-methoxy-methylidene]-3-methyl-piperidine

Participants

Reaction Conditions

Reaction Steps

Potassium t-butoxide (1.56 g) was added portionwise to a stirred suspension of methoxymethyltriphenylphosphonium chloride (4.76 g) in tetrahydrofuran (30 ml) at 0° C. under argon. The resulting orange mixture was stirred at 0° C. for 30 min., then 1-(4-chlorocinnamyl)-3-methyl-piperidin-4-one (1.83 g, prepared by alkylation of 3-methyl-piperidin-4-one [CAS No 5773-58-0] with 4-chloro-cinnamyl chloride) dissolved in a minimum volume of tetrahydrofuran was added dropwise and the resulting solution was stirred at room temperature for 1 hour, poured into water and extracted twice with ether. The combined organic layers were dried over sodium sulphate and concentrated in vacuo. The residue was purified by silica gel chromatography (cyclohexane:ethyl acetate 75:25) to afford 1-(4-chlorocinnamyl)-4-[1-methoxy-methylidene]-3-methyl-piperidine as a mixture of diastereoisomers. MS (ES+) 292/294 (M+H+).

Provenance & Evidence