Abstract: The present invention provides an improved method of chromatographically separating the isomers of (1R,rR)-atracurium salts by high-performance liquid chromatography (HPLC), in the absence of a strong acid. The separation is preferably performed on a silica gel HPLC column using an eluent containing an organic solvent, a polar aprotic co-solvent and a weak organic acid.

Abstract: The present invention provides novel isoquinolinium compounds, methods of producing the isoquinolinium compounds, and methods for converting them into cisatracurium, e.g., cisatracurium besylate. The isoquinolinium compounds of the present invention can be obtained in the form of solids, which can be purified using simple techniques and can be used to afford pure cisatracurium besylate without HPLC purification.

Abstract: The present invention provides an improved method for obtaining cisatracurium besylate, which preferably chromatographically separating cisatracurium besylate from a mixture of (1R,1?R)-atracurium isomers via flash chromatography.

Abstract: The present invention provides R,R?-atracurium salts, processes for producing and purifying such salts, and methods of using such salts to produce highly pure cisatracurium besylate.

Abstract: The present invention provides processes for producing isoquinolinium compounds, and for converting them into cisatracurium salts, e.g.

Abstract: The present invention provides compounds which are useful, e.g., as reference markers for analyzing the purity of cisatracurium and salts thereof, a test method for determining the said purity and processes for preparing reference markers.

Abstract: Provided is a process for producing highly pure 4-amino-1-isobutyl-1H-imidazo[4,5-c]quinoline (imiquimod), which includes reacting 4-chloro-1-isobutyl-1H-imidazo[4,5-c]quinoline with a non-gaseous amine precursor. Also provided are methods for isolating highly pure imiquimod. Further provided are intermediates useful in the production of imiquimod, methods for producing such intermediates, and methods for obtaining imiquimod from such intermediates.

Abstract: The present invention provides a process of producing cisatracurium compounds, e.g., cisatracurium besylate, from isoquinolinium salts of the structural formula (VIIA) wherein X? is an anion and R is H or a C1-C6 alkyl, or an activated form of the carboxylic acid with 1,5-pentanediol to form a cisatracurium salt, optionally via an intermediate compound (VIII). The cisatracurium compounds can be purified using simple techniques to afford pure cisatracurium besylate without the need for HPLC purification.

Abstract: The present invention provides R,R?-atracurium salts processes for producing and purifying such salts, and methods of using such salts to produce highly pure cisatracurium besylate.

Abstract: The present invention provides processes for producing isoquinolinium compounds, and for converting them into cisatracurium salts, e.g.

Abstract: The present invention provides an improved method for obtaining cisatracurium besylate, which preferably chromatographically separating cisatracurium besylate from a mixture of (1R,1?R)-atracurium isomers via flash chromatography

Abstract: The present invention provides novel isoquinolinium compounds, methods of producing the isoquinolinium compounds, and methods for converting them into cisatracurium, e.g., cisatracurium besylate.

Abstract: Derivatives of 1,2-benzisoxazole-3-methanesulfonic acid, which are non-hygroscopic and non-hydrated and their use as intermediates from the preparation of zonisamide are disclosed. Further disclosed are processes of preparing zonisamide from these 1,2-benzisoxazole-3-methanesulfonic acid derivatives, processes of preparing exemplary 1,2-benzisoxazole-3-methanesulfonic acid derivatives and crystalline forms of exemplary 2-benzisoxazole-3-methanesulfonic acid derivatives. A novel process of preparing zonisamide is also disclosed.

Abstract: The present invention provides an improved method of chromatographically separating the isomers of (1R,rR)-atracurium salts by high-performance liquid chromatography (HPLC), in the absence of a strong acid. The separation is preferably performed on a silica gel HPLC column using an eluent containing an organic solvent, a polar aprotic co-solvent and a weak organic acid.

Abstract: Provided is a method for separating cisatracurium from a mixture of atracurium isomers, which method includes eluting from a Reverse Phase (RP) stationary phase with a mobile phase in which the isomers are stable. The method of the present invention can be conveniently and inexpensively scaled up.

Abstract: The present invention provides a process for preparing highly pure 4-amino-1-isobutyl-1H-imidazo[4,5-c]quinoline (imiquimod). The process preferably includes heating 4-chloro-1-isobutyl-1H-imidazo[4,5-c]quinoline of formula (II) with ammonia in a polar aprotic solvent at relatively moderate pressure to produce imiquimod, and optionally purifying the imiquimod. The process of the present invention can produce highly pure imiquimod in high yield.

Abstract: The present invention provides a process for preparing highly pure Temozolomide base which includes recovery from the purification mother liquors by using an anionic exchange resin. By treating Temozolomide hydrochloride with a mixture of an organic acid, a water miscible organic solvent, and water, Temozolomide free base is obtained in an acidic medium. Due to the high sensitivity of Temozolomide to basic pH values the recovery-including process is especially advantageous because it enables obtaining high yields of highly pure Temozolomide base in acidic conditions. The process for producing Temozolomide base includes hydrolysis of the starting material 8-cyano-3-methyl-[3H]-imidazo[5,1-d]-tetrazin-4-one in acidic medium to obtain highly pure Temozolomide hydrochloride in high yield.

Abstract: The present invention provides a crystalline donepezil maleate, which is used as an intermediate in the preparation of donepezil hydrochloride. Also provided are novel processes for producing same in substantially pure form and a process for producing pharmaceutically pure amorphous donepezil hydrochloride therefrom.

Abstract: The present invention provides processes for preparing intermediates useful in the preparation of gemcitabine and other nucleosides, and processes for preparing gemcitabine therewith. Exemplary intermediates include mixtures of D-erythro and D-threo isomers of 3-(hydroxy)-2,2-difluoro-3-(2,2-dimethyldioxolan-4-yl)-propionic acid salts. Also provided is a process for selectively isolating the D-erythro and D-threo isomers of D-erythro and D-threo isomers of 3-(hydroxy)-2,2-difluoro-3-(2,2-dimethyldioxolan-4-yl)-propionic acid salts, and processes for using such isomers in the preparation of nucleoside analogs such as, e.g., gemcitabine, intermediates thereof, and analogs thereof.

Abstract: A novel process for preparing (2?,3?,5?,16?,17?)-17-acetoxy-3-hydroxy-2-(4-morpholinyl)-16-(1-pyrrolidinyl) androstane, a known intermediate in the synthesis of the skeletal muscle relaxant rocuronium bromide, is disclosed.