反应详情

5-Methyl-2-oxo-cyclohexanecarboxylic acid ethyl ester (45) (5.9 g, 32 mmol), DMAP (1.12 g, 10 mmol) and diethylamine (4.7 g, 65 mmol, 6.7 mL) in toluene (90 mL) were heated at reflux for 4 days. The reaction was allowed to cool and the toluene was removed under reduced pressure to give a yellow oil. The crude material was purified by silica gel chromatography eluting with petrol (A) and ethyl acetate (B) (20-50% B, 80 g) to afford 4.4 g (65%) of 5-methyl-2-oxo-cyclohexanecarboxylic acid diethylamide (46) as a yellow oil. The structure was confirmed 1H NMR (300 MHz, CDCl3) δH 0.8-1.05 (9H, m, CH3 and N(CH2CH3)2), 1.05-2.10 (5H, m, 5-CH and 4- and 6-CH2), 2.15-2.80 (2H, m, 3-CH2), 2.95-3.55 (5H, m, 1-CH and N(CH2CH3)2).

1. temperatureat reflux for 4 days
2. temperatureto cool
3. customthe toluene was removed under reduced pressure
4. customto give a yellow oil
5. customThe crude material was purified by silica gel chromatography
6. washeluting with petrol (A) and ethyl acetate (B) (20-50% B, 80 g)