Lithium Hydroxide → Methyl 6-bromo-1-methyl-1H-indole-2-carboxylate

Participants

Reaction Steps

6-Bromo-1-methyl-1H-indole-2-carboxylic acid methyl ester was prepared by N-methylation of 6-bromo-1H-indole-2-carboxylic acid ethyl ester using the procedure described in Example 13 for N-methylation of indole carboxylic acid esters. Ester hydrolysis was performed with LiOH (4 equ.) in methanol-water 4:1, 12 h at room temperature. The reaction mixture was partitioned between ethyl acetate and water. The aqueous phase was acidified to pH˜2-3 with 2N HCl and extracted in ethyl acetate. The organic phase was washed with brine, dried (Na2SO4) and evaporated in vacuo to yield 95% of 6-bromo-1-methyl-1H-indole-2-carboxylic acid [(1S,2R)-2-cyanomethyl-carbamoyl)-cyclohexyl]-amide; m/z 253.

Provenance & Evidence