Water → 1,3-Dihydro-1-oxoisobenzofuran-5-carbonitrile

Participants

Reaction Conditions

Reaction Steps

5-Carboxyphthalid (50 g, 0.28 mole) and sulfamide (31 g, 0.32 mole) were suspended in sulfolane (150 mL). Thionylchloride (41 g, 0.34 mole) was added and the temperature was raised to 130-140° C. for 2 hours. At about 90° C., gas evolution took place. The mixture was allowed to cool to 90° C. and water (150 mL) was added. The temperature was held at 85-90° C. for 15 min and then the solution was cooled to 35° C. The crystals were filtered off and washed with water (250 mL). The title compound was crystallised from acetic acid.Yield: 34.5 g, 77%. DSC onset: 203° C. Purity: 98.5% (hplc, peak area). 1H NMR (DMSO-d6, 500 MHz): 5.48 (2H, s), 8.03 (2H, s), 8.22 (1H, s). 13C NMR (DMSO-d6, 125 MHz): 70.0, 116.1, 188.0, 126.0, 127.5, 129.0, 132.8, 147.7, 169.3.

Provenance & Evidence