The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 09, 2010
Filed:
Jan. 11, 2010
Andrzej Kutner, Warsaw, PL;
Michal Chodynski, Pruszkow, PL;
Kinga Leszczynska, Warsaw, PL;
Wieslaw Szelejewski, Warsaw, PL;
Hanna Fitak, Warsaw, PL;
Andrzej Kutner, Warsaw, PL;
Michal Chodynski, Pruszkow, PL;
Kinga Leszczynska, Warsaw, PL;
Wieslaw Szelejewski, Warsaw, PL;
Hanna Fitak, Warsaw, PL;
Instytut Farmaceutyczny, Warszawa, PL;
Abstract
A process for the preparation of calcipotriol at least including: (a) reacting a C-22 phenylsulfonyl derivative of cholecalciferol of Formula 2, wherein Rand Rare the same or different and represent hydroxyl protecting groups, with a silyl derivative of alfa-hydroxy aldehyde of Formula 3, wherein Rrepresents silyl group of formula Si(R)(R)(R), where R-Rare the same or different and represent Calkyl or phenyl groups, in the presence of a strong organic base in an aprotic solvent, followed by reductive desulfonation of the obtained diastereomeric mixture of alfa-hydroxysulfones with sodium amalgam, removal of the hydroxyl protecting groups, and purification of the product. The process leads to the formation of calcipotriol containing less than 0.3% of the (22Z)-isomer. The obtained calcipotriol is free of mercury traces.