Dimethylformamide → Ethyl 3,3-dimethyl-5-[(phenylsulfonyl)amino]pentanoate

Temperature

70 °C

Benzenesulphonamide (9.6 g, 61.1 mmol) was added to a stirred solution of sodium methoxide (1.6 g, 29.6 mmol) in methanol (100 ml). The clear solution was evaporated to dryness, then dimethyl formamide (100 ml) and ethyl 5-bromo-3,3-dimethyl-pentanoate (7.0 g, 32.8 mmol) were added and the mixture was heated for eight hours at 70° C. The solution was then poured into water (600 ml), the mixture was extracted with ether and the ether phase, after being dried over sodium sulphate, was evaporated. Treatment of the solid residue with a mixture of toluene and cyclohexane (9:1) left most of the unreacted benzenesulphonamide undissolved. After filtration, the solution was evaporated and the residue was purified by chromatography on silica gel with a mixture of methylene chloride and ethanol (98:2). Yield: 4.6 g (50% of theory), oily substance, nD20 =1.5083.

1. customThe clear solution was evaporated to dryness
2. extractionthe mixture was extracted with ether
3. dry with materialthe ether phase, after being dried over sodium sulphate
4. customwas evaporated
5. additionTreatment of the solid residue with a mixture of toluene and cyclohexane (9:1)
6. waitleft most of the unreacted benzenesulphonamide undissolved
7. filtrationAfter filtration
8. customthe solution was evaporated
9. customthe residue was purified by chromatography on silica gel with a mixture of methylene chloride and ethanol (98:2)

ORD record

ord-de89c71efb1840d2ad5f68b8e41a8566

Source dataset

uspto-grants-1991_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04997847