1-methyl-1H-pyrrolo[2,3-c]pyridine-3-carbaldehyde synthesis

Yield:860297-50-3 45%

Reaction Conditions:

Stage #1: 1-methyl-1H-pyrrolo[2,3-c]pyridine;hexamethylenetetraminewith trifluoroacetic acid at 80; for 4 h;
Stage #2: with sodium hydroxide in water;

Steps:

35.b

b) 1-Methyl-lH-pyrrolo [2, 3-c]pyridine-3-carbaldehyde; 1-Methyl-lH-pyrrolo [2,3-c] pyridine (0.180 g, 1.36 mmol) and hexamethylenetaetramine (0.38 g, 2.7 mmol) were dissolved in 5 mL of TFA and heated to 80°C for 4h with stirring. TFA was evaporated and the residue was partitioned between water and EtOAc. The mixture was made alkaline by addition of 2M NaOH. The aqueous layer was extracted with EtOAc twice and the combined organic layer was washed with water, dried over Na2SO4 and evaporated. The crude product was flash chromatographed on silica with DCM/MeOH 95/5. Yield: 99 mg (45%). 'H NMR (300 MHz, CDCl3) 8 10.02 (s, 1H), 8.81 (bd, 1H), 8.47 (d, 1H), 8.12 (m, 1H), 7.78 (s, lH), 3.97 (s, 3H).

References:

WO2005/66132,2005,A1 Location in patent:Page/Page column 87