反应详情

N,N-Dicyclohexylcarbodiimide (515 mg, 2.5 mmol) was added to an ice-cooled solution of 4-methoxycarbonyl-2-(2-methylpropyl)but-2-enoic acid (500 mg, 2.5 mmol) and O-methyl-L-tyrosine N-methylamide (520 mg, 2.5 mmol) in dry dichloromethane (30 ml), and the mixture was stirred at room temperature for 18 h. The precipitated solid was filtered off and washed with a little dichloromethane, then the organic solution was washed successively with 1 N hydrochloric acid (20 ml), 1 N sodium bicarbonate (20 ml), and water. The solution was dried (MgSO4) and evaporated in vacuo. Column chromatography (30 g silica) of the residual solid, eluting with 5% methanol/dichloromethane gave the title compound (520 mg, 53%), m.p. 142°-144° C. (dichloromethane/pentane).

1. filtrationThe precipitated solid was filtered off
2. washwashed with a little dichloromethane
3. washthe organic solution was washed successively with 1 N hydrochloric acid (20 ml), 1 N sodium bicarbonate (20 ml), and water
4. dry with materialThe solution was dried (MgSO4)
5. customevaporated in vacuo
6. washColumn chromatography (30 g silica) of the residual solid, eluting with 5% methanol/dichloromethane