4-CHLORO-5-NITRO-1-(PHENYLSULFONYL)-1H-PYRROLO[2,3-B]PYRIDINE synthesis

Yield: 95%

Reaction Conditions:

with tetramethylammonium nitrate;trifluoroacetic anhydride in dichloromethane at -5 - 20; for 20.5 h;

Steps:

1.2
Step 2: l-Benzenesulfonyl-4-chloro-5-nitro-lH-pyrrolo[2,3-6]pyridineTo a stirred solution of l-(benzenesulfonyl)-4-chloro-pyrrolo[2,3-&]pyridine (50 g 170.8 mmol), in dichloromethane (750 mL) at -5 °C tetra-methyl ammonium nitrate (29.0 g, 213.5 mmol) was added in portions followed by drop wise addition of trifluoroacetic anhydrideo(31.4 mL, 222.0 mmol), stirring was continued below 0 C for 30 min and another 16 h at room temperature. Tetramethyl ammonium nitrate (5.8g, 42.7 mmol) was added in portions followed by dropwise addition of trifluoroacetic anhydride (7.25 mL, 51.2 mmol) and stirring for another 4 h at room temperature. Reaction mixture was diluted with dichloromethane, washed with water, dried over sodium sulphate and concentrated under reduced pressure. The residue was triturated with methanol and filtered through buchnor funnel to afford 1- benzenesulfonyl-4-chloro-5-nitro-lH-pyrrolo[2,3-6]pyridine as yellow solid (55 gm, 95%). 1H NMR (400 MHz, DMSO-i¾): δ 9.0br s, 1H), 8.28 (d, J= 4.0 Hz, 1H), 8.17 (d, J= 7.6 Hz, 2H), 7.80-7.77 (m, 1H), 7.69-7.65 (m, 2H), 7.1 1 (d, J= 4.0 Hz, 1H).

References:

ADVINUS THERAPEUTICS LIMITED;BARAWKAR, Dinesh;BENDE, Tanushree;ZAHLER, Robert;BANDYOPADHYAY, Anish;SARANGTHEM, Robindro Singh;DOSHI, Jignesh;WAMAN, Yogesh;JADHAV, Rushikesh;SINGH, Umesh Prasad WO2012/127506, 2012, A1 Location in patent:Page/Page column 60