反应详情

To a solution of (4) (1.964 g, 7.92 mmol) in ethanol (140 ml) was added potassium carbonate (0.547 g, 3.96 mmol) and the solution was refluxed for 30 minutes. After concentration in vacuo, dichloromethane was added and the mixture was washed with saturated aqueous sodium. chloride solution. Concentration in vacuo gave crude crystalline solid which was purified by recrystallisation in toluene/60-80 petroleum ether giving the title compound (5) (0.968 g, 95%); mp 60° C.; νmax (CDCl3) 1758 cm-1 ; [α]D24 (c 2 in CHCl3)=+1.2; (Found: C, 56.13; H, 8.85; N, 10.79. C6H11NO2 requires C, 55.80; H, 8.58; N, 10.84%); δH (500 MHz; CDCl3) 1.12 (3H, d, J=6.6, CHCH3), 1.27 (3H, s, C(CH3)2), 1.39 (3H, s, C(CH3)2), 3.59 (1H, J=6.5, CHCH3), 7.27 (1H, s, NH); δC (125 MHz; CDCl3) 16.07 (CH3), 21.46 (CH3), 27.14 (CH3), 57.12 (CH), 83.50 (C), 159.00 (CO); m/z (CI+, NH3) 130 (M+ +1).

1. temperaturethe solution was refluxed for 30 minutes
2. concentrationAfter concentration in vacuo, dichloromethane
3. additionwas added
4. washthe mixture was washed with saturated aqueous sodium
5. concentrationConcentration in vacuo
6. customgave crude crystalline solid which
7. customwas purified by recrystallisation in toluene/60-80 petroleum ether giving the title compound (5) (0.968 g, 95%)