Abstract: Disclosed is a method of preparing 3-hydroxytetrahydrofuran using cyclodehydration. More particularly, this invention relates to a method of preparing 3-hydroxytetrahydrofuran, including subjecting 1,2,4-butanetriol to cyclodehydration under reaction conditions of a reaction temperature of 30˜180° C. and reaction pressure of 5000 psig or less in the presence of a strong acid cation exchange resin catalyst having a sulfonic acid group as an exchange group. According to the method of this invention, 3-hydroxytetrahydrofuran can be economically prepared at higher yield and productivity than when using conventional methods.

Abstract: Disclosed is a method of preparing 3-hydroxytetrahydrofuran using cyclodehydration. More particularly, this invention relates to a method of preparing 3-hydroxytetrahydrofuran, including subjecting 1,2,4-butanetriol to cyclodehydration under reaction conditions of a reaction temperature of 30˜180° C. and reaction pressure of 5000 psig or less in the presence of a strong acid cation exchange resin catalyst having a sulfonic acid group as an exchange group. According to the method of this invention, 3-hydroxytetrahydrofuran can be economically prepared at higher yield and productivity than when using conventional methods.

Abstract: 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.

Abstract: 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.

Abstract: Disclosed is a continuous process for the production of optically pure (S)-?-hydroxy-?-butyrolactone having constantly maintained optical activity, consisting of hydrogenating 2-50 wt % of a substituted carboxylic acid derivative in a solvent using a fixed bed reactor filled with a precious metal catalyst-impregnated inorganic oxide carrier at 50-500° C. under pressure of 15-5,500 psig at weight-space-velocity of 0.1-10 h?1, in which a molar ratio of hydrogen to carboxylic acid derivative ranges from 2 to 10. The desired material can be produced in higher optical purity and at higher yield by the current process which is relatively simpler and environmentally safer than conventional processes. Additionally, increased production efficiency leads to production of the desired material on a large scale.

Abstract: 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.

Abstract: 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−1, to a fixed bed reactor which is filled with a catalyst and maintained at a reaction temperature of 50 to 550° 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.

Abstract: 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−1, to a fixed bed reactor which is filled with a catalyst and maintained at a reaction temperature of 50 to 550° 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.