2H-Pyrrolo[2,3-b]pyridin-2-one, 6-chloro-1,3-dihydro-3,3-dimethyl-

220896-14-0

74-88-4

1581754-84-8

a) A suspension of anhydrous THF (10.5 mL) of potassium tert-butoxide (3.2 g, 28.0 mmol) was mixed with a suspension of anhydrous THF (8.1 mL) of 6-chloro-1H-pyrrolo[2,3-b]pyridin-2(3H)-one (1 g, 5.59 mmol) under argon protection and ice-bath cooling conditions. Subsequently, copper(I)-dimethyl sulfide bromide complex (116 mg, 559 μmol) was added. A solution of THF (1 mL) in iodomethane (1.59 g, 11.2 mmol) was added slowly and dropwise over 15 min at the same temperature. After removing the ice bath, the reaction mixture was stirred at room temperature for 30 min. After that, the reaction mixture was cooled to 0 °C and saturated aqueous NH4Cl solution (20 mL) was added. The aqueous phase was extracted with EtOAc, the organic layers were combined, washed with water, dried over Na2SO4 and the solvent was concentrated under reduced pressure. The crude product was purified by silica gel column chromatography using heptane/ethyl acetate as eluent to afford 6-chloro-3,3-dimethyl-1H-pyrrolo[2,3-b]pyridin-2(3H)-one as a pink solid (470 mg).MS ESI (m/z): 197.1/199.2 [(M + H)+].1H NMR (CDCl3, 300 MHz) δ= 8.13 (br s, 1H), 7.39 (d, J = 7.9 Hz, 1H), 7.00 (d, J = 7.7 Hz, 1H), 1.42 (s, 6H).