反应详情

To a solution of 5-bromo-4-oxo-4,5,6,7-tetrahydro-indole 1,3-dicarboxylic acid 1-tert-butyl ester 3-ethyl ester (1.66 mmol) in 15 mL 1,4-dioxane is added acetamidine hydrochloride (3.32 mmol). After stirring under refluxing for 16 hours the solvent is removed in vacuo. To the residue is added 14 mL CHCl3 and 2 mL MeOH and the mixture is stirred for 10 min. The solid is filtered off. The mother liquid is concentrated and is chromatographed using 10% MeOH in CH2Cl2 as mobile phase to yield 2-methyl-3,4,5,6-tetrahydro-imidazo[4,5-e]indole-8-carboxylic acid ethyl ester as a white solid (30%). 1H NMR (DMSO-d6) 1.30 (t, 3H), 2.28 (s, 3H), 2.70 (t, 2H), 2.79 (t, 2H), 4.22 (q, 2H), 7.20 (s, 1H), 10.58 (s, 1H), 11.43 (s, 1H).

1. temperatureunder refluxing for 16 hours the solvent
2. customis removed in vacuo
3. additionTo the residue is added 14 mL CHCl3 and 2 mL MeOH
4. stirringthe mixture is stirred for 10 min
5. filtrationThe solid is filtered off
6. concentrationThe mother liquid is concentrated
7. customis chromatographed