Reaction #502132

Reaction equation

naproxen

4-mercapto-l-butanol

1-(3-(dimethylamino)propyl)-3-ethylcarbodiimide hydrochloride

4-mercapto-l-butanol

→

(2S)-1-(4-Hydroxybutylthio)-2-(6-methoxy(2-naphthyl))propan-1-one

Yield 30.0%

Solvents

dichloromethane

Conditions

Workup

1. 1
   Otherpartitioned between dichloromethane and water
2. 2
   Washthe water layer was washed with more dichloromethane
3. 3
   WashThe combined organic layer was washed with water and brine
4. 4
   Dryingdried over magnesium sulfate
5. 5
   ConcentrationThe solution was concentrated under vacuum
6. 6
   Otherthe residue was purified via column chromatography, 50% ethyl acetate/hexane
7. 7
   Otherthe solvent removed by rotary evaporation
8. 8
   Otherto give an oil, 2.647 g, which

Procedure

To a solution of naproxen (5.03 g, 21.9 mmol), 4-mercapto-l-butanol (2.32 g, 21.9 mmol) and N,N-dimethylaminopyridine (DMAP) (0.534 g, 4.37 mmol) in dichloromethane (200 mL) at room temperature was added 1-(3-(dimethylamino)propyl)-3-ethylcarbodiimide hydrochloride (EDAC) (5.03 g, 26.2 mmol) as a solid, in portions. The reaction mixture was stirred for 3 hours at room temperature, then partitioned between dichloromethane and water, and the water layer was washed with more dichloromethane. The combined organic layer was washed with water and brine, then dried over magnesium sulfate. The solution was concentrated under vacuum, and the residue was purified via column chromatography, 50% ethyl acetate/hexane. The appropriate fractions were combined, and the solvent removed by rotary evaporation to give an oil, 2.647 g, which contained 19% 4-mercapto-l-butanol by weight (product weight 2.07 g, 6.5 mmol, 30% yield): 1H NMR (300 MHz, CDCl3) δ 7.73 (d, J=2.7 Hz, 1H), 7.71 (d, J=2.3 Hz, 1H), 7.69 (d, J=1.0 Hz, 1H), 7.40 (dd, J=1.8, 8.5 Hz, 1H), 7.15 (dd, J=2.5, 8.8 Hz, 1H), 7.12 (d, J=2.3 Hz, 1H), 4.02 (q, J=7.1 Hz, 1H), 3.92 (s, 3H), 3.61-3.64 (m, 2H), 2.87 (m, 2H), 1.61 (d, J=7.1 Hz, 3H), 1.59 (m, 2H), 1.41 (m, 2H); mass spectrum (API-TIS) m/z 319 (M+H+), 336 (M+18+).

Source