Bentazon → HCID 20334433, compound

Participants

Reaction Steps

To 100 ml of acetonitrile was added 11.6 g of the potassium salt of 3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide. To the resultant stirred mixture was added dropwise 5.4 ml of trimethylacetyl chloride in 50 ml of acetonitrile over a 0.5 hour period. The resultant mixture was heated at 38°-40° C. for 22 hours, cooled, filtered and the solvent removed from the filtrate in vacuo. The residue was dissolved in 100 ml of ether and extracted with 100 ml of 5% potassium carbonate. The ether layer was washed once with 100 ml of water, dried with magnesium sulfate and filtered. The solvent was removed from the filtrate in vacuo and the solid residue, 8.3 g, extracted with 3-10 ml-portions of methanol. The resultant precipitate was air dried to afford 4.5 g of 3-(1-methylethyl)-1-(2,2-dimethyl-1-oxopropyl)-1H- -2,1,3-benzothiadiazin-4 (3H)-one-2,2-dioxide, m.p. 97.5°-99.5° C.

Provenance & Evidence