Certain sulfonylurea compounds such as 2-[[[4-methoxy-6-(methylselenylmethyl)pyrimidin-2-yl]aminocarbonyl]aminosu lfonyl]benzoic acid, methyl ester and 2-[[[4-methoxy-6-(phenylthiomethyl)pyrimidin-2-yl]-aminocarbonyl]aminosulf onyl]benzoic acid, methyl ester provide herbicidal activity.