反应详情

A solution of 4-(1'-hydroxyethyl)-piperidine (13 g, m.p. 65°-68° C.) in ethanol (25 ml) was neutralized with 5 N hydrogen bromide in ethanol. After removal of the solvent in vacuo, the residue was distilled twice with chloroform and finally dried at 0.05 mm Hg. The oily residue was mixed with phosphorous tribromide (25 ml) and heated on the steam bath for 2 hours. After cooling, the mixture was treated with ether (250 ml) to give a crystalline precipitate which was filtered off and washed with ether to give (A) as hygroscopic crystals. Recrystallization from acetonitrile gave material with m.p. 146°-48° C.

1. customAfter removal of the solvent in vacuo
2. distillationthe residue was distilled twice with chloroform
3. customfinally dried at 0.05 mm Hg
4. additionThe oily residue was mixed with phosphorous tribromide (25 ml)
5. temperatureheated on the steam bath for 2 hours
6. temperatureAfter cooling
7. additionthe mixture was treated with ether (250 ml)
8. customto give a crystalline precipitate which
9. filtrationwas filtered off
10. washwashed with ether