Abstract: The invention pertains to a process for preparing a succinic acid ester comprising the steps of bringing an aqueous liquid comprising succinic acid, alcohol, and at least 5 wt. % of a dissolved chloride salt selected from magnesium chloride, calcium chloride, and zinc chloride, calculated on the weight of the liquid, to reaction conditions, thereby obtaining a succinic acid ester, and recovering the succinic acid ester and an aqueous solution comprising the dissolved chloride salt. It has been found that the process according to the invention shows a high yield and has a high reaction rate. Additionally, it has been found that the process makes it possible to carry out the separation of the succinic acid ester from the aqueous reaction medium in high yield.
Abstract: Provided are processes for the purification of a pure rosuvastatin intermediate by thin film evaporation and chemical method, and conversion of the intermediate to rosuvastatin or salts thereof.
Type:
Grant
Filed:
July 14, 2008
Date of Patent:
February 8, 2011
Assignee:
Teva Pharmaceutical Industries, Ltd.
Inventors:
Tamar Nidam, Omer Malachi, Irena Veinberg, Valerie Niddam-Hildesheim, Vinod Kumar Kansal, Harish Ranjan, Appu Ekambaram Ponnuswamy, Sunil Rokad, Surat Kiran, Debashish Das
Abstract: Provided are processes for the purification of a pure rosuvastatin intermediate by thin film evaporation and chemical method, and conversion of the intermediate to rosuvastatin or salts thereof.
Type:
Application
Filed:
July 14, 2008
Publication date:
April 16, 2009
Inventors:
Tamar Nidam, Omer Malachi, Irena Veinberg, Valerie Niddam-Hildesheim, Vinod Kumar Kansal, Harish Ranjan, Appu Ekambaram Ponnuswamy, Sunil Rokad, Surat Kiran, Debashish Das
Abstract: The invention is directed to a process for producing a stable, low odor S,S,S-tributylphosphorotrithioate having a level of dibutyl disulfide of 0.3% by weight or less. The process broadly includes the steps ofa) reacting S,S,S-tributylphosphorotrithioite with an oxidizing agent to produce a crude S,S,S-tributylphosphorotrithioate,b) treating the crude product with sodium bisulfite to decompose any excess oxidizing agent,c) adding a caustic solution having a caustic concentration of from 25 to 50% by weight directly to the reaction mixture of step b), the addition of said caustic solution being stopped once the total caustic concentration is less than 10% by weight and once the pH is constant, andd) phase separating S,S,S-tributylphosphorotrithioate from the mixture of step c).
Type:
Grant
Filed:
June 20, 1997
Date of Patent:
November 3, 1998
Assignee:
Bayer Corporation
Inventors:
Vidyanatha A. Prasad, Peter E. Newallis