Hydrochloric Acid → (S)-1'-(tert-butyl)-2'-oxo-1',2',5,7-tetrahydrospiro[cyclopenta[b]pyridine-6,3'-pyrrolo[2,3-b]pyridine]-3-carboxylic acid

Participants

Reaction Steps

A mixture of 7 (5.0 g, 14.5 mmol), K2CO3 (5.01 g, 36.2 mmol), Pd(OAc)2 (33 mg, 0.145 mmol), 1,3-bis(dicyclohexylphosphino)propane (DCPP, 127, mg, 0.290 mmol) and water (0.522 mL, 29.0 mmol) in NMP (32 mL) was heated at 120° C. under 30 psi of CO for 24 h. After cooling to room temperature, the resulted slurry was diluted with water (100 mL). The pH was slowly adjusted to 3˜4 with 2 N HCl. The slurry was aged at room temperature for 1 h, filtered, rinsed with water (40 to 50 mL), dried under oven at 60° C. to give 8 (4.64 g, 95%) as a solid. 1H NMR (DMSO-d6, 500 MHz): δ 8.90 (s, 1H), 8.19 (d, J=5.2 Hz, 1H), 7.54 (d, J=7.3 Hz, 1H,), 6.99 (dd, J=7.3, 5.2 Hz, 1H), 3.33 (m, 4H), 1.72 (s, 9H); 13C NMR (DMSO-d6, 125 MHz): δ 180.16, 167.44, 166.97, 158.07, 149.76, 146.61, 135.39, 133.09, 130.36, 128.81, 125.48, 118.44, 58.19, 51.12, 44.56, 41.24, 28.91.

Provenance & Evidence