Chloroacetone → 6-Bromo-2-methylpyridin-3-amine

Participants

Reaction Steps

Using a procedure similar to that described in Example 1, except using 2-amino-3-(5-bromo-2H-pyrazolo[4,3-b]pyridin-2-yl)-2-methylpropionitrile (33 mg), the title compound was isolated as a white solid (46 mg, 84%). Rf=0.4 (1:1 EA/heptane). MS (ES): M/Z [M+H]=468. 1H NMR: (400 MHz, DMSO-d6): 1.69 (s, 3H), 5.06-5.24 (m, 2H), 7.44 (d, J=9.0 Hz, 1H), 7.53 (d, J=8.1 Hz, 2H), 7.97 (d, J=8.8 Hz, 2H), 8.12 (d, J=9.0 Hz, 1H), 8.69 (s, 1H) and 8.96 (s, 1H). 19F NMR (376 MHz, DMSO-d6): −57.1 (s, 3F). 2-Amino-3-(5-bromo-2H-pyrazolo[4,3-b]pyridin-2-yl)-2-methylpropionitrile [40 mg, 73%; Rf=0.35 (EA)] was prepared using a procedure similar to that described in Example 1, part b, except starting from 1-(5-bromo-2H-pyrazolo[4,3-b]pyridin-2-yl)propan-2-one (50 mg). 1-(5-Bromo-2H-pyrazolo[4,3-b]pyridin-2-yl)propan-2-one [80 mg, 12%; Rf=0.25 (2:1 EA/heptane)] was prepared using a procedure similar to that described in Example 182 part g using chloroacetone and potassium carbonate except starting from 5-bromo-1H-pyrazolo[4,3-b]pyridine (0.5 g). 5-Bromo-1H-pyrazolo[4,3-b]pyridine (0.5 g, 24%) was prepared using a procedure similar to that described in Example 182 part f except starting from 3-amino-6-bromo-2-methylpyridine (2 g). 3-Amino-6-bromo-2-methylpyridine [3.2 g, 93%; Rf=0.75 (1:1 EA/heptane)] was prepared using a procedure similar to that described in Example 182 part e except starting from 6-bromo-2-methyl-3-nitropyridine (4 g).

Provenance & Evidence