Ammonium Chloride → tert-Butyl 4-{4-[(Z)-2-(naphthalen-1-yl)ethenyl]-1,3-thiazol-2-yl}piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

Under argon, (1-naphthylmethyl)triphenylphosphonium chloride (2.96 g) is dissolved in 20 ml of tetrahydrofuran and cooled to 0° C., and potassium tert.-butoxide (757 mg) is added, whereupon the colour of the solution changes to dark-red. After 10 min of stirring, tert-butyl 4-(4-formyl-1,3-thiazol-2-yl)piperidine-1-carboxylate (1.00 g) is added. The mixture is stirred at 0° C. for another 30 min and then slowly warmed to room temperature. After a further 20 min, saturated ammonium chloride solution is added, and the aqueous phase is separated off. After extraction of the aqueous phase with ethyl acetate, the combined organic phases are dried over sodium sulphate and concentrated under reduced pressure. After chromatographic purification, this gives tert-butyl 4-{4-[(Z)-2-(naphthalen-1-yl)ethenyl]-1,3-thiazol-2-yl}piperidine-1-carboxylate (1.2 g, Z isomer).

Provenance & Evidence