Synthesis of 3-Methyl-4-oxo-3,4-dihydroquinazoline-5-sulfonamide and a Herbicidal Sulfonylurea Derivative

Starting with 6-chloroquinazolin-4(3H)-one (5), a convenient synthesis of 3-methyl-4-oxo-3,4-dihydroquinazoline-5-sulfonamide (11) has been achieved. The sulfonamide (11) was used to prepare a highly herbicidal sulfonylurea derivative (13).