Phosgene → 2,2-Dimethyl-2,3-dihydro-1-benzofuran-7-sulfonyl isocyanate

Participants

Reaction Steps

A suspension of 22 g of the N-(n-butylaminocarbonyl)-2,3-dihydro-2,2-dimethyl-7-benzofuransulfonamide prepared in Example 3, in 125 ml of xylene containing 0.3 g of DABCO was heated at 130°-135° C. while 5.3 ml of phosgene was added portionwise at a rate to maintain a reflux temperature of 130°-135° C. The mixture was refluxed for an additional 1.5 hours, cooled under nitrogen, and concentrated to dryness in vacuo. A sample of the crude oily product displayed a characteristic sulfonyl isocyanate band in the IR at 2200 cm-1.

Provenance & Evidence