Hanmi Pharm. Co., Ltd.

Hanmi Pharmaceutical Co., Ltd.

Hanmi Pahrm. Co., Ltd.

Nam-Du Kim

Gwan-Sun Lee

Kwee-Hyun Suh

Mi-Ra Seong

Kyung-Ik Lee

Young-ho Moon

Young-Kil Chang

Jae-Heon Lee

Jong-Soo Woo

Gi-Jeong Kim

Hyoung-Jun Pae

Sang-Min Yun

Kwan-Sun Lee

Young-Ho Moon

Moon-Sub Lee

Risperidone is prepared in a high yield by reacting 2,4-difluorophenyl(4-piperidinyl)methanone oxime hydrochloride and 3-(2-chloroethyl)-6,7,8,9-tetrahydro-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one in an aqueous alkali hydroxide solution having an alkali hydroxide concentration in the range of 20 to 40%.

Method for preparing risperidone

Amlodipine camsylate of the present invention is a crystalline salt of amlodipine suitable for pharmaceutical formulation, which is prepared by using low toxic camphor sulfonic acid to meet required pharmaceutical properties for treating cardiovascular diseases.

Amlodipine camsylate and method for preparing thereof

Clarithromycin can be easily prepared by reacting erythromycin A N-oxide with a methylating agent to obtain 6-O-methylerythromycin A N-oxide; and treating 6-O-methylerythromycin A N-oxide obtained above with a reducing agent in a high yield.

Method of preparing clarithromycin

A new erythromycin A 9-oxime compound which can be effectively used as intermediates for the preparation of erythromycin A oxime compound, a process for preparing the same and a process for preparing 6-O-alkyl erythromycin A or its oxime using the same is described.

Erythromycin a compounds and process for preparing the same

High purity Form II crystals of clarithromycin can be easily prepared in a high yield by a process comprising the steps of: protecting the 9-oxime hydroxy group of erythromycin A 9-oxime or a salt thereof with a tropyl group and the 2&prime;- and 4&Prime;-hydroxy groups with trimethylsilyl groups; reacting 2&prime;,4&Prime;-O-bis(trimethylsilyl)erythromycin A 9-O-tropyloxime with a methylating agent; removing the protecting groups and the oxime group of 2&prime;,4&Prime;-O-bis(trimethylsilyl)-6-O-methylerythromycin A 9-O-tropyloxime to obtain crude clarithromycin; treating the crude clarithromycin with methanesulfonic acid in a mixture of a water-miscible organic solvent and water to obtain crystalline clarithromycin mesylate trihydrate; and neutralizing the crystalline clarithromycin mesylate trihydrate with aqueous ammonia in a mixture of a water-miscible organic solvent and water.

Method of preparing form II crystals of clarithromycin

Amlodipine is prepared in a high yield by subjecting a pyrrole derivative, methyl aminocrotonate and 2-chlorobenzaldehyde to a Hantzsch reaction, and converting the pyrrole residue of the resulting 1,4-dihydropyridine derivative to an amine group by the action of hydroxylamine hydrochloride.

Method for preparing amlodipine

Pure Form II crystals of clarithromycin can be prepared by a simple, high-yield process comprising the steps of treating crude clarithromycin or different crystal forms of clarithromycin with formic acid in an organic solvent to obtain crystalline clarithromycin formate and neutralizing the clarithromycin formate with a base in a mixture of water and a water-miscible organic solvent.

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Osan-si, South Korea

Nam-Du Kim