Propylene Glycol → 1,2-propylene Glycol bis(2-mercaptoisobutyrate)

Temperature

70 °C

In a 200-ml eggplant-shaped flask were charged 4.57 g (60 mmol) of 1,2-propylene glycol, 15.86 g (132 mmol) of 2-mercaptoisobutanoic acid, 1.20 g (6.3 mmol) of p-toluenesulfonic acid monohydrate, and 100 g of methylene chloride (manufactured by Junsei Chemicals Co., Ltd.), and a Soxhlet extractor which was loaded with Molecular sieves 4A (manufactured by UNION SHOWA K.K.) and a condenser tube were equipped thereto. While the contents being stirred, they were heated at an oil bath temperature of 70° C. After the reaction was performed for 30 hours, the reaction mixture was neutralized with 200 ml of an aqueous 10% sodium hydrogen carbonate. Further, the reaction mixture was washed with deionized water three times, and then dehydrated and dried over anhydrous magnesium sulfate. Then, the methylene chloride was distilled off and the residue was subjected to column chromatography with silica gel to purify PGMIB. The silica gel used was Wako Gel C-200, and n-hexane/ethyl acetate=6/1 (by volume ratio) was used as an elution solvent. The PGMIB obtained by the purification was a colorless transparent liquid and the yield was 4.00 g (24%). The PGMIB had a compositional formula of C11H20O4S2 and a molecular weight of 280.41.

1. customwere equipped
2. washFurther, the reaction mixture was washed with deionized water three times
3. dry with materialdried over anhydrous magnesium sulfate
4. distillationThen, the methylene chloride was distilled off
5. customto purify PGMIB
6. customThe PGMIB obtained by the purification

ORD record

ord-a01c3d83f7204dd7b64bf40ca4d344da

Source dataset

uspto-grants-2008_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07341828B2