Pyridine → Methyl 4-iodo-2-isocyanatosulfonylbenzoate

Participants

Reaction Steps

50 g of the sulfonamide obtained in Example 6 are suspended in 150 ml of 1,2-dichloroethane and the suspension is treated with 27.7 ml of thionyl chloride. The mixture is heated at the boil for 4 hours, cooled to 50°-55° C. and treated with 0.5 ml of pyridine, and phosgene is passed for 31/2 hours into the solution which has now been brought to the boil. The mixture is concentrated under reduced pressure with the exclusion of moisture. The crude sulfonyl isocyanate which remains (52.6 g) crystallises upon standing.

Provenance & Evidence