3-Iodo-4-azaindole-5-carboxylic acid synthesis

Yield:1190311-30-8 72.6%

Reaction Conditions:

with iodine;potassium hydroxide in N,N-dimethyl-formamide at 20; for 1 h;

Steps:

9

Preparation of compound 9a: 3-iodo-lH-pyrrolo[3,2-b]pyridine-5-carboxylic acidTo a solution of lH-pyrrolo[3,2-b]pyridine-5-carboxylic acid (0.400 g, 2.467 mmol, Adesis, New Castle, DE) in DMF (4.9 mL) was added I₂ (0.626 g, 2.467 mmol) and KOH (0.346 g, 6.17 mmol). The mixture was stirred at RT for 1 h. The mixture was poured into ice and H₂0 (30 mL) containing sodium bisulfite (0.257 g, 2.467 mmol). The reaction was acidified with 5 M HCl. A yellow solid precipitated out and was collected by filtration, washed with H₂0 and dried overnight in a vacuum oven to give 3-iodo-lH- pyrrolo[3,2-b]pyridine-5-carboxylic acid (0.516 g, 1.791 mmol, 72.6 % ). MS (ESI, pos. ion) m/z: 289.0 (M+l). ^.H NMR (400 MHz, DMSO-d₆) δ ppm 7.91 (2 H, s), 8.01 (1 H, d, J=2.74 Hz), 12.03 - 12.11 (1 H, m).

References:

WO2012/129338,2012,A1 Location in patent:Page/Page column 84