Abstract: The invention comprises a process for preparing quetiapine and/or its salts, including, quetiapine fumarate. The process generally comprises reacting dibenzothiazepinone (dibenzo[bf][1,4]thiazepin-11(10H)-one) with phosphorous oxychloride in the presence of triethylamine in an aromatic organic solvent such as toluene or, preferably, xylene at reflux temperature to obtain an aromatic hydrocarbon solution of 11-chloro-dibenzo[bf][1,4]thiazepine. Thereafter, the 11-chloro-dibenzo[bf][1,4]thiazepine is reacted with 2-(2-piperazin-1-ylethoxy)-ethanol to yield, following several processing steps, quetiapine. Compound I can then be further reacted with fumaric acid at elevated temperature to yield quetiapine fumarate. The resulting quetiapine fumarate obtained is suitable for use in pharmaceutical preparations.

Abstract: The invention provides a process for preparing gabapentin and its intermediates. The process generally involves treating gabapentin lactam with an aqueous solution of hydrobromic acid to yield gabapentin hydrobromide salt as an intermediate, which can be isolated by filtration. The gabapentin hydrobromide salt can then be hydrolyzed with a base, such as an organic amine, to yield gabapentin that can be isolated by filtration.

Abstract: The present invention relates to a method for differentiating and quantifying the enantiomers, thereby determining the enantiomeric purity, of darifenacin and its intermediate compounds and salts thereof. In addition, the invention relates to a method for differentiating and quantifying the enantiomers, thereby determining the enantiomeric purity of compounds of formula (I): wherein Y is hydrogen or a substituent of the formula: including the differentiation and quantification of compounds of formula (I) of varying enantiomeric purity from their corresponding enantiomers. The invention further relates to a process for preparing enantiomerically pure darifenacin using enantiomerically pure starting compounds which have been previously differentiated and quantified according to the method of the invention.

Abstract: The present invention relates to a process for preparing racemic narwedine (which can be can be kinetically resolved) to yield (?)-narwedine and which is the biogenic precursor of (?)-galanthamine) and the use thereof as a starting material for producing (?)-galanthamine. The invention further includes processes for preparing (?)-galanthamine and (?)-galanthamine hydrobromide, as well as related novel compounds.

Abstract: The present invention relates to a novel process for the preparation of montelukast sodium, a compound of Formula (1b) and precursors thereof. The invention further concerns the free acid of this compound in crystalline form, obtainable for the first time by the new process.

Abstract: The present invention is directed to intermediate compounds of mirtazapine and methods for obtaining same. A method is described for obtaining (±)-3-phenyl-1-methylpiperazine, an important intermediate for obtaining mirtazapine, which is based on imposing a cyclization reaction, in the presence of a reducing agent, on new compounds of general formula (1) in which Z is a leaving group capable of undergoing a nucleophilic displacement. A method is also described for obtaining the new compounds of formula (1).

Abstract: Intermediate compounds for the preparation of mirtazapine and obtention methods thereof.

Abstract: The invention relates to a process for the preparation of 4-amino-1-hydroxybutylidene-1,1-bisphosphonic acid and of the trihydrated monosodium salt thereof, consisting of reacting 4-aminobutyric acid with a phosphonation mixture formed by phosphorous acid and methanesulfonic anhydride and thereafter hydrolyzing the product of said reaction and isolating the products by adjustment of the pH.

Abstract: The invention discloses a process for the preparation of the polymorh A of doxazosin meylate, consisting essentially of reacting doxazosin base with methanesulfonic acid in a mixture of solvents containing an alcohol and a chlorinated solvent, subsequently removing the chlorinated solvent by distillation and precipitating the desired product in an alcohol, after heating the suspension formed to the reflux temperature of the solvent.

Abstract: A process for the preparation of venlafaxin and/or the physiologically acceptable addition salts thereof that consists of reacting a compound of general formula (II) where R is a C1-C10 alkyl, aryl, aralkyl or cycloalkyl group of 3 to 6 atoms of carbon, with a organomagnesium compound of general formula (III) where X is an atom of halogen and, if desired, a salt of the thus obtained venlafaxin is formed by reaction thereof with a physiologically acceptable acid.