Hydrochloric Acid → 3-[2,4-Dichloro-6-fluorobenzothiazol-7-yl]-6-trifluoromethyl-2,4(1H,3H)-pyrimidinedione

Participants

Reaction Conditions

Reaction Steps

1.6 g of sodium hydride (97% strength) in 200 ml of absolute dimethylformamide were initially taken. 11.0 g of ethyl 3-amino-4,4,4-trifluorobut-2-enecarboxylate were then added dropwise at from 0° to 5° C. Stirring was carried out for one hour at this temperature, after which the mixture was cooled to -30° C. and 16.2 g of 2,4-dichloro-6-fluoro-7-isocyanatobenzothiazole in 50 ml of absolute tetrahydrofuran were then added dropwise. The mixture was stirred for one hour at this temperature and then slowly warmed up to room temperature. Thereafter, ice water was added and the pH was brought to 3-4 with dilute hydrochloric acid, after which the product was extracted with ethyl acetate. The ester solution was dried and then evaporated down.

Provenance & Evidence