Potassium Carbonate → HCID 89793832, compound

Participants

Reaction Steps

To a solution of (R)-6-ethyl-1-tosyl-5,6-dihydropyrrolo[3,4-b]pyrrol-4(1H)-one (505e, 3.49 g, 11.47 mmol) in MeOH (50 mL) in an ice bath was added potassium carbonate (3.17 g, 22.93 mmol) in one portion. The resulting white suspension was stirred in an ice bath for 1 h and at RT for 1 h. The suspension was filtered through a pad of Celite washing with MeOH. 10 g silica gel was added to the filtrate and concentrated in vacuo. It was purified on the ISCO Combiflash RF (40 g Grace Reveleris column, using a gradient of 0-20% 2 M NH3/MeOH in DCM) affording (R)-6-ethyl-5,6-dihydropyrrolo[3,4-b]pyrrol-4(1H)-one (966 mg, 6.43 mmol, 56% yield) as a tan solid. m/z (ESI, +ve) 151.1 (M+1)+. The material was further purified by chiral SFC (mobile phase CO2/15% MeOH (20 mM NH3), chiral column AS (250×30 mm), wave length 245 nm, flow rate 120 mL/min) The second eluting peak was collected and concentrated in vacuo to give (R)-6-ethyl-5,6-dihydropyrrolo[3,4-b]pyrrolo-4(1H)-one (505f, 450 mg, 3.00 mmol, 26% yield) as an off-white crystalline solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 11.31 (1H, br. s.), 7.55 (1H, s), 6.83 (1H, t, J=2.3 Hz), 6.07 (1H, dd, J=2.7, 1.6 Hz), 4.31 (1H, t, J=5.9 Hz), 1.50-1.74 (2H, m), 0.85 (3H, t, J=7.4 Hz). m/z (ESI, +ve) 151.1 (M+1)+.

Provenance & Evidence