Sk Corporation

Ki-Ho Koh

Byong-Sung Kwak

Ki-Nam Chung

Choon-Gil Kim

Hee-Jun Hwang

Tae-Yun Kim

Jin-Woong Kim

Disclosed is a method of preparing 10H-dibenzo[b,f][1,4]thiazepin-11-one, including reacting dithiosalicylic acid with 1-chloro-2-nitrobenzene in a basic aqueous solution in the presence or absence of a reducing agent, to prepare 2-(2-nitrophenylsulfuryl)benzoic acid; subjecting the 2-(2-nitrophenylsulfuryl)benzoic acid to nitro group reduction in the presence of hydrogen, a solvent and a heterogeneous metal catalyst, to prepare 2-(2-aminophenylsulfuryl)benzoic acid; and directly cyclizing the 2-(2-aminophenylsulfuryl)benzoic acid in an organic solvent in the presence or absence of an acid catalyst. The method according to the present invention is economical due to the use of the inexpensive starting material, and also environmentally friendly and efficient by minimizing the use of the organic solvent and performing direct cyclization without the activation of carboxylic acid.

Method of preparing 10H-dibenzo[b,f][11,4]thiazepin-11-one

Disclosed is a method for preparing serinol (2-amino-1,3-proanediol). From nitromethane, para-formaldehyde and sodium hydroxide, 1-nitro-1,3-propanediol sodium salt is prepared as a medical intermediate. In a fixed bed, this intermediate is allowed to undergo the continuous hydrogenation of 2-nitro-1,3-propanediol sodium salt and methanol as shown in reaction (1). In addition to being simple, the method is economically favorable and affords the high yield and high purity of serinol.

Method for the production of serinol

Disclosed is a process for the production of optically pure (S)-beta-hydroxy-gamma-butyrolactone through the hydrogenation of substituted carboxylic acid derivatives. A solution containing 1 to 50% by weight of a substituted carboxylic acid derivative is fed at a WHSV of 0.1 to 10 h , to a fixed bed reactor which is filled with a catalyst and maintained at a reaction temperature of 50 to 550&deg; C. under a halogen partial pressure of 15 to 5,500 psig. The catalyst is composed of a noble metal as a catalytically effective ingredient which is impregnated in an inorganic oxide as a support. The molar ratio of the hydrogen to the substituted carboxylic acid derivative is maintained at a molar ratio of 1:1 to 10:1. The process can produce optically pure (S)-beta-hydroxy-gamma-butyrolactone with higher purities at higher yields than can conventional techniques. In addition to being relatively simple and environmentally friendly, the process is so economically favorable as to apply to industrial production.

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Taejon, South Korea

Ki-Ho Koh