Lonza Inc.

Bristol-myers Squibb Compnay

Lothar Zimmermann

Erick Moran Carreira

Aleksander Warm

Nicka Chinkov

Meinrad Brenner

Miriam Lorenzi

The invention is directed to a process for the preparation of a cyclic carbamate starting with o-aminobenzyl alcohol and/or a suitable salt thereof, which is reacted with a cyclization agent selected from phosgene, diphosgene, triphosgene and mixtures thereof, and in that the reaction 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-alkyl C-carboxylates and mixtures of at least one C-alkyl C-carboxylate with at least one C-alkane.

Process for the synthesis of cyclic carbamates

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 cyclization 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-alkyl C-carboxylates and mixtures of at least one C-alkyl C-carboxylate with at least one C-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.

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Brigerbad, Switzerland

Lothar Zimmermann