| 摘要 |
The invention is directed to a process for the preparation of a cyclic carbamate starting with a chiral propargylic alcohol and/or a suitable salt thereof, which is reacted with a cyclisation agent selected from phosgene, diphosgene, triphosgene and mixtures thereof, and in that the reaction is carried out in the presence of an aqueous base, and a water-immiscible organic solvent, said organic solvent mainly comprising at least one compound selected from C 2-5 -alkyl C 2-5 -carboxylates and mixtures of at least one C 2-5 -alkyl C 2-5 -carboxylate with at least one C 5-8 -alkane. Another aspect of the invention is directed to a process for the synthesis of said cyclic carbamate starting described above, wherein also a process for the preparation of the chiral propargylic alcohol is provided. |
