反应详情

A solution of 2.32 g (4.59 mmol) of (±)-2,6-dimethyl-3-carbomethoxy-4-(3-nitrophenyl)-5-(2-phthalimidoethyloxycarbonyl)-1,4-dihydropyridine and 344 mg of hydrazine monohydrate in 100 ml of ethanol is heated at reflux for 2 hr. TLC indicates the reaction is incomplete so another 1.5 equivalents of hydrazine monhydrate is added and the mixture refluxed for an additional hr. After cooling, the precipitate is collected by filtration, washed with ethanol, and the filtrate evaporated under vacuum to leave a yellow solid. This solid is taken up in 125 ml of CH2Cl2, washed twice with 0.5 N KOH, once with water, dried (MgSO4), filtered, and the solvent removed under vacuum to give 1.70 g of (±)-2,6-dimethyl-3-carbomethoxy-4-(3-nitrophenyl)-5-(2-aminoethoxycarbonyl)-1,4-dihydropyridi ne as a yellow solid. 1H-NMR (CDCl3); δ 1.85 (s, 2H); 2.40 (d, 6H); 3.40 (t, 2H); 3.68 (s, 3H); 4.35 (s, 2H); 5.15 (s, 1H); 5.90 (s, 1H); 7.40 (t, 1H) 7.68 (d, 1H); 8.03 (d, 1H); 8.13 (s, 1H).

1. temperatureat reflux for 2 hr
2. additionis added
3. temperaturethe mixture refluxed for an additional hr
4. temperatureAfter cooling
5. filtrationthe precipitate is collected by filtration
6. washwashed with ethanol
7. customthe filtrate evaporated under vacuum
8. customto leave a yellow solid
9. washwashed twice with 0.5 N KOH, once with water
10. dry with materialdried (MgSO4)
11. filtrationfiltered
12. customthe solvent removed under vacuum