Sodium Hydroxide → 4-(2-Methyl-thiazol-4-ylmethoxy)-1H-indole-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

4-(2-Methyl-thiazol-4-ylmethoxy)-indole-1,2-dicarboxylic acid 1-tert-butyl ester 2-ethyl ester (169) (1.75 g, 4.2 mmol) is dissolved in 20 ml of ethanol. After addition of a 0.5M aqueous sodium hydroxide solution (33.6 ml, 16.8 mmol) the solution is heated to 60° C. and stirred at this temperature for 18 h. Then the reaction mixture is evaporated and the residue is dissolved in ethyl acetate. AT 0° C. conc HCl is added until a pH of 1 is reached. The organic phase is washed with water and brine. The organic layers are dried over sodium sulphate, filtrated. The product crystallized upon evaporation and could be filtrated off.

Provenance & Evidence