Triethylamine → Tert-butyl 4-(2,2-dibromovinyl)piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A solution of 160.86 g (613.3 mmol) of triphenylphosphine in 600 ml CH2Cl2 was treated with 101.7 g (306.6 mmol) of tetrabromomethane (the reaction heated up to 32° C.) and after 50 min at 20° C., 97.8 ml (705.3 mmol) of triethylamine was added (the reaction heated up to 35° C. and the color became dark violet). After cooling (0° C.), 32.7 g (153.4 mmol) of 4-Formyl-piperidine-1-carboxylic acid tert-butyl ester in 380 ml CH2Cl2 were added slowly (20 min). The solution was stirred over night at RT, evaporated and filtered through silica gel (deactivated with hexane/Et3N; with hexane and then hexane/ether 4:1 to 1:1) to give 42.54 g (75%) of 4-(2,2-dibromo-vinyl)-piperidine-1-carboxylic acid tert-butyl ester, mp: 82.3-83.9° C., MS: 368 (MH+, 2Br).

Provenance & Evidence