Patent ID: 8163926
Filing Date: 2012-04-24
Classification: A61P,C07D

Abstract:
1. A process for the manufacture of a compound of the Formula IIa: wherein R is a suitable sulphonate ester; from a (C1-C6)alkyl-4-piperidinecarboxylate compound of the Formula III: which process comprises the steps of: (a) reacting the (C1-C6)alkyl-4-piperidinecarboxylate compound of the Formula III with di-tert-butyl dicarbonate in the presence of toluene or xylene to form a first mixture comprising toluene or xylene, tert-butanol and a compound of the Formula IV: (b) substantially removing the tert-butanol from the first mixture; (c) reacting the compound of the Formula IV with a suitable reducing agent in situ in the presence of toluene or xylene to form a second mixture comprising toluene, reduction by-products including alcohol by-products and a compound of the Formula V: (d) substantially removing the alcohol by-products from the second mixture; and (e) reacting the compound of the Formula V with a suitable sulphonylating agent in situ to form a sulphonate ester in the presence of a suitable base and toluene to form the compound of the Formula IIa.