Abstract

D7]Bentazone was sysnthesized from methyl antranilate and [D7 isopropylsulfamoyl chloride. [D7]Isopropylsulfamoyl chloride was prepared by treatment of [D7]isopropyl amine with chlorosulfonic acid and phosphorous pentachloride. The overall yield from D7]isopropyl amine was 7% and the isotopic purity was estimated to be >95%. Direct deuteration of bentazone with deuterium oxide did not occur and the temperature used for this deutarition (100 degr. C) caused a rearrangement. Attempts to prepare bentazone by substitution of isopropyl iodide or isopropyl toxylate to the potassium-sodium- or cesiumsalt of 1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide failed.