[NH2:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][C:10]=1[OH:11])[NH:7][C:6]([C:12]([O:14][CH3:15])=[O:13])=[CH:5]2.[O:16]1CC[CH2:18][CH2:17]1.C(=O)([O-])O.[Na+].ClCC(Cl)=O.C(=O)([O-])[O-].[K+].[K+]>>[O:16]=[C:17]1[CH2:18][O:11][C:10]2[CH:9]=[C:8]3[NH:7][C:6]([C:12]([O:14][CH3:15])=[O:13])=[CH:5][C:4]3=[CH:3][C:2]=2[NH:1]1To a solution of 2.0 g (9.7 mmol) of methyl 5-amino-6-hydroxy-indole-2-carboxylate (Example 5/c) in 300 ml of tetrahydrofuran 2.45 g (29.2 mmol) of sodium hydrogencarbonate and 1.3 ml (16.3 mmol) of chloroacetyl chloride are added and the mixture is stirred at room temperature overnight. The reaction mixture is concentrated and 100 ml of water is added to the residue. The precipitated crystals are filtered off, washed with water and suspended in 120 ml of acetonitrile. 4.05 g (29.3 mmol) of potassium carbonate is added to the suspension and the resulted mixture is stirred at room temperature overnight. The reaction mixture is concentrated and 100 ml of water is added to the residue. The product is filtered off, washed with water and dried to yield 1.7 g (71%) of the title compound. Mp.: 188-196° C. (water).
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