反应详情

To a solution of 4-benzyloxy-3-ethyl-5-methylbenzoic acid (4.38 g, 17.2 mmol) in chloroform (60 mL), thionylchloride (5 mL, 68.9 mmol) is added. The mixture is refluxed for 2.5 h before the solvent is evaporated in vacuo. The remaining red oil is dissolved in THF (150 mL) and then added dropwise to a solution of hydrazine hydrate (3.46 g, 69.3 mmol) in THF (80 mL). The mixture is stirred 2 h at rt, diluted with diethyl ether, washed with 1 N aq. HCl, dried over MgSO4, filtered, concentrated and dried to give 4-benzyloxy-3-ethyl-5-methyl-benzoic acid hydrazide (1.16 g) as a white solid; LC-MS: tR=0.82 min, [M+1]+=285.47, 1H NMR (CDCl3): δ 0.98 (t, J=7.3 Hz, 3H), 1.98 (s, 3H), 2.39 (q, J=7.3 Hz, 2H), 4.49 (s, 2H), 7.20-7.32 (m, 5H) 7.57 (s, 1H), 7.65 (s, 1H), 11.23 (s, 1H).

1. temperatureThe mixture is refluxed for 2.5 h before the solvent
2. customis evaporated in vacuo
3. dissolutionThe remaining red oil is dissolved in THF (150 mL)
4. washwashed with 1 N aq. HCl
5. dry with materialdried over MgSO4
6. filtrationfiltered
7. concentrationconcentrated
8. customdried