Hydrochloric Acid → Tert-butyl 4-(chlorocarbonyl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

The same reaction procedure used in the reference of Tetrahedron Letters. Vol 35 839-842, 1994 was made. 15.78 g (84.7 mmol) of 1-(t-butoxycarbonylamino)piperazine, 6.85 ml (84.7 mmol) of pyridine and 15.1 ml (84.7 mmol) of diisopropylethylarine were dissolved in 200 ml of anhydrous toluene and then carbonic acid gas was intromitted for 1 hour under -10° C. The reaction solution was added to 80 ml of toluene solution of 10.6 ml (84.7 mmol) of thionylchloride being cooled under -10° C. and stirred for 1 hour. The reaction solution was added to 0.1 N hydrochloric acid and the toluene layer was separated out. The reaction mixture was dried over anhydride sodium sulfate and concentrated under reduced pressure. These crystals thus obtained were washed with hexane, whereby 13.7 g of 4-(2-methyl-2-propyloxycarbonyl)piperazine-1-carbonylchloride was obtained.

Provenance & Evidence