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Dapremont
Olivier Dapremont, Folsom, CA US
| Patent application number | Description | Published |
|---|---|---|
| 20110065938 | METHOD FOR THE PREPARATION OF ESCITALOPRAM - A novel method is provided for the manufacture of escitalopram. The method comprises chromatographic separation of the enantiomers of citalopram or an intermediate in the production of citalopram using a chiral stationary phase such as Chiralpak™ AD or Chiralcel™ OD. Novel chiral intermediates for the synthesis of Escitalopram made by said method are also provided. | 03-17-2011 |
Olivier Dapremont, Citrus Heights, CA US
| Patent application number | Description | Published |
|---|---|---|
| 20080275246 | PROCESS FOR HALOMETHYL ETHERS OF HYDROXYIMINOMETHYL QUATERNARY PYRIDINIUM SALTS - A halide salt of a 1-(hydroxyiminomethyl-1-pyridino)-3-(halomethyl)-2-oxapropane is prepared by adding a pyridinealdoxime to a bis-halomethylether in such a manner that the bis-halomethylether is maintained in excess throughout the addition. This procedure produces the halide salt of a 1-(hydroxyiminomethyl-1-pyridino)-3-(halomethyl)-2-oxapropane in high yield and purity, which facilitates its use as an intermediate in the manufacture of an asymmetrically substituted 1,3-di(1-pyridino)-2-oxapropane, a class of compounds that are generally useful antidotes to various toxic agents. A prominent member of the class is the dimethylsulfonate salt of 1-(2-hydroxyiminomethyl-1-pyridino)-3-(4-carbamoyl-1-pyridino)-2-oxapropane. The use of mercaptoalkyl-functionalized polymers is disclosed as a preferred metal ion scavenger for a final purification step in the manufacture of these compounds. | 11-06-2008 |
| 20080287704 | PREPARATIVE-SCALE SEPARATION OF ENANTIOMERS OF CHIRAL CARBOXYLIC ACIDS - High yields and purity are obtained in the purification of enantiomers of chiral carboxylic acids by preparative-scale chromatography by including a tertiary alcohol in the mobile phase in conjunction with an acidic modifier and a hydrophobic solvent. The tertiary alcohol is superior to other, more commonly used alcohols by reducing the extent of esterification of the enantiomer that otherwise lowers the yield and the purity. | 11-20-2008 |
| 20090242486 | SIMULATED MOVING BED CHROMATOGRAPHY FOR STRONGLY RETAINED COMPOUNDS - Simulated moving bed (SMB) chromatography involving a series of columns serially connected in a circuit is performed in a modified protocol by dividing the columns into two groups isolated from flow communication with each other and using one of the two groups solely for extraction of the more strongly retained component from the solid phase while the other group is operated in the conventional SMB manner. The sites of introduction and withdrawal and the site of division between the two groups of columns are all rotated around the circuit as in conventional SMB chromatography, but the process is capable of separating component mixtures with non-linear isotherms and of extracting solutes that are very strongly retained on the solid phase. | 10-01-2009 |
Olivier Dapremont, Cameron Park, CA US
| Patent application number | Description | Published |
|---|---|---|
| 20120024785 | REACTION SYSTEMS WITH INCORPORATED CHROMATOGRAPHY UNITS FOR ENHANCED PRODUCT RECOVERY - Product yields in chemical reactions that produce a solid product from a liquid reaction mixture are improved by chromatographically separating certain key impurities from the product mixture prior to crystallization, or from the filtrate after crystallization in which case further product is crystallized from the filtrate. The removal of key impurities either before the first crystallization or between the first and second crystallizations facilitates the crystallization of product to produce a higher yield of product. | 02-02-2012 |