Potassium Carbonate → 3-Oxo-2,3-dihydro-1H-inden-5-yl ethyl(methyl)carbamate

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Reaction Steps

Ethylmethyl carbamyl chloride (15.5 g, 127.57 mmol) was added to a stirred suspension of 6-hydroxy-1-indanone (17.2 g, 116.1 mmol) and potassium carbonate (31.8 g, 188 mmol) in acetonitrile (800 mL) at room temperature over a period of 15 minutes. The reaction mixture was heated to reflux and refluxed for 18 hours. The reaction mixture was cooled to ambient temperature, the solvent evaporated and the residue was diluted with water (250 mL) and extracted three times with toluene (250 mL). The combined organic phase was dried on MgSO4 and toluene was evaporated in a rotary evaporator. The crude crystalline product was purified by crystallization from 2-propanol (200 mL), collected by filtration, and dried under vacuum at 50° C. to afford the title compound (22 g, 81.5%). 1H NMR (300 MHz, CDCl3) δ ppm 7.47-7.44 (2H, m, Ar), 7.36 (1H, dd, J 8.4 and 2.1, Ar), 3.52-3.37 (2H, m, NCH2CH3), 3.14-3.108 [2H, m, OCCH2CH2 and incl. NCH3 (two rotamers), at 3.08 and 2.99 (3H, s, Me)], 2.74-2.71 (2H, m, OCCH2 CH2) and 1.25 and 1.19 (two rotamers) (3H, two triplets, J6.9). Mass Spectrum (FAB+) [MH+]=234

Provenance & Evidence