Phosgene → 3-Methyl-2,2-dioxo-1,2-benzoxathiin-8-ylsulfonylisocyanate

Participants

Reaction Steps

5.0 g of N-(3-methyl-2,2-dioxo-1,2-benzoxathiin-8-ylsulfonyl)-N'-methylurea are dispersed in 150 ml of absolute chlorobenzene and the dispersion is saturated with phosgene at 130° C. A clear solution forms during this addition. The solvent is subsequently distilled off in vacuo with the exclusion of moisture. The 3-methyl-2,2-dioxo-1,2-benzoxathiin-8-ylsulfonylisocyanate obtained as oily residue can be used without further purification for the preparation of the pyrimidinylureas and triazinylureas of the formula I.

Provenance & Evidence