Dimethyl Sulfoxide → 4-(Benzyloxy)butanoic acid

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Reaction Conditions

Reaction Steps

4.0 g (60%, 0.1 mol) of sodium hydride were washed in hexane and mixed with 30 ml of dry DMSO, and the resulting admixture was stirred at 60° C. on an oil bath for 1 hour under a nitrogen gas flow. The mixture was stirred at room temperature, and dry DMSO containing 12.6 g (0.1 mol) of sodium 4-hydroxybutyrate (100 ml) was added. After stirring at room temperature for 2 hours, the reaction solution was cooled on an ice bath, 0.2 mol of benzyl bromide was added, and the reaction was carried out at room temperature for 2 hours. After solidification, 0.5 L of ether was added, the admixture was filtered, the resulting residue was washed with ether (300 ml×3), and the filtrate was concentrated under vacuum. The resulting residue was mixed with 100 ml of methanol, 100 ml of 8% sodium hydroxide were added, and the admixture was stirred at 60° C. for 15 hours. After drying under vacuum, the resulting concentrated residue was washed with ether (200 ml×2), and the ether layer was extracted with 1 N sodium hydroxide (50 ml). All aqueous layers were combined, neutralized with concentrated hydrochloric acid (pH<4) and then extracted with ether (100 ml×5). The ether layer was extracted with 2 N sodium hydroxide (50 ml×3), all water layers were neutralized with concentrated hydrochloric acid (pH<4), and further extracted with ether. The resulting product was washed with an aqueous saturated sodium chloride solution, dried on magnesium sulphate, and then concentrated under vacuum. 9.42 g of 4-benzyloxybutyric acid was obtained as a pale yellow oil.

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