Abstract: Disclosed herein are methods of obtaining highly pure 5-azacytidine, which contains minimal amounts of degradation impurities and methods of assessing the impurity profile of the degradation of cytidine analogues, such as 5-azacytidine

Abstract: A process for preparing pure levocetirizine and salts thereof, e.g., the levocetirizine dihydrochloride, and a pharmaceutical composition comprising levocetirizine dihydrochloride produced by the process are disclosed.

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: A novel process is disclosed for producing Imatinib, using the precursor 2-chloro-4-(3-pyridyl)-pyrimidine, thus improving Imatinib preparation via an alternative synthetic route, avoiding the use of the toxic reagent cyanamide.

Abstract: Provided is a process for purifying a letrozole product that contains an isoletrozole impurity, which process preferably includes converting at least a portion of the isoletrozole impurity into 4,4?-dicyanobenzophenone and removing 4,4?-dicyanobenzophenone, to produce a purified letrozole product.

Abstract: Provided is a process for preparing gemcitabine or a salt thereof, which preferably includes selectively precipitating the ?-anomer of a 3?,5?-di-O-protected-N4-trimethylsilyl-2?-deoxy-2?,2?-difluorocytidine, removing the protecting groups to produce gemcitabine, and, optionally, converting the gemcitabine into a salt. Preferably, the 3? and 5? protecting groups are the same or different, and at least one of the 3? and 5? protecting groups is cinnamoyl, naphthoyl, naphthylmethylcarbonyl, 2-methylbenzylcarbonyl, 4-methylbenzylcarbonyl or 9-fluorenylmethyloxycarbonyl. Also provided are methods for enriching the ?-anomer from an anomeric mixture of a 3?,5?-di-O-protected-N4-trimethylsilyl-2?-deoxy-2?,2?-difluorocytidine, e.g., a N4-trimethylsilyl-2?-deoxy-2?,2?-difluoro-cytidine-3?,5?-diester, e.g., 3?,5?-dicinnamoyl-N4-trimethylsilyl-2?-deoxy-2?,2?-difluorocytidine, using a slurrying process, and methods for converting the ?-anomer-enriched product into gemcitabine or a salt thereof.

Abstract: The present invention is directed to a process of preparing montelukast or a salt thereof with minimal amounts of impurities, such as a dehydration impurity (compound (VI)) or a cyclic ether impurity (compound (VIII)).

Abstract: The present invention provides a process for preparing 4-amino-1-isobutyl-1H-imidazo[4,5-c]quinoline (Imiquimod) of formula (I). The process comprises heating 4-chloro-1-isobutyl-1H-imidazo[4,5-c]quinoline of formula (II) with formamide, and optionally with bubbling of gaseous ammonia to afford Imiquimod of formula (I). According to the present invention, by using this process and novel purification methods, essentially as described herein, highly pure Imiquimod is obtained.

Abstract: The present invention provides a process for preparing 4-amino-1-isobutyl-1H-imidazo[4,5-c]quinoline (Imiquimod) of formula (I). The process comprises heating 4-chloro-1-isobutyl-1H-imidazo[4,5-c]quinoline of formula (II) with formamide, and optionally with bubbling of gaseous ammonia to afford Imiquimod of formula (I). According to the present invention, by using this process and novel purification methods, essentially as described herein, highly pure Imiquimod is obtained.

Abstract: Provided is a process for purifying a letrozole product that contains an isoletrozole impurity, which process preferably includes converting at least a portion of the isoletrozole impurity into 4,4?-dicyanobenzophenone and removing 4,4?-dicyanobenzophenone, to produce a purified letrozole product.

Abstract: A novel process is disclosed for producing Imatinib, using the precursor 2-chloro-4-(3-pyridyl)-pyrimidine, thus improving Imatinib preparation via an alternative synthetic route, avoiding the use of the toxic reagent cyanamide.

Abstract: The present invention relates to an improved process of alkylating secondary amines, more particularly of alkylating compounds having amino piperidinic group, which are useful as donepezil intermediates, wherein an alcohol serves as reaction facilitator thus enabling to obtain donepezil and salts thereof in high quality and yield. The present invention also relates to the prevention of unwanted alkylation of donepezil precursors, having amino piperidinic group, by using suitable reaction conditions.

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 novel processes for purifying anastrozole, devoid of using liquid chromatography. The purification processes are via the isolated anastrozole salt forms, either by crystallization or by selective acidic extractions, and optionally in both cases, converting the purified anastrozole salt to anastrozole base. Also provided is an improved process for the synthesis of anastrozole, which is obtained by alkylating the isolated and purified starting material 3,5-bis(2-cyanoprop-2-yl)benzylbromide, the process being devoid of using toxic, hazardous and environmental unfriendly solvents and reagents.