Yield:6577-89-5 97%

Reaction Conditions:

Stage #1: ethyl 3-methyl-4-oxo-4,5,6,7-tetrahydro-1H-indole-2-carboxylatewith sodium hydroxide in ethanol; for 1 h;Reflux;
Stage #2: with hydrogenchloride in water;

References:

Barraja, Paola;Diana, Patrizia;Montalbano, Alessandra;Carbone, Anna;Cirrincione, Girolamo;Viola, Giampietro;Salvador, Alessia;Vedaldi, Daniela;Dall'Acqua, Francesco [Bioorganic and Medicinal Chemistry,2008,vol. 16,# 22,p. 9668 - 9683] Location in patent:experimental part