Hydrochloric Acid → Cyclopropanecarboxylic acid (3,4-dibromo-isothiazol-5-yl)-amide

Participants

Reaction Steps

Add bromine (118.3; mL, 2.30; mol) over 1; hour to a cooled aqueous solution of sodium hydroxide (3.77; M, 2.44; L, 9.21; mol) at 0° C. and stir 15; min. To this solution, add a solution of cyclopropanecarboxylic acid (4-acetyl-3-bromo-isothiazol-5-yl)-amide (155.7; g, 0.51; mol) in 1,4-dioxane (856.3; mL, 10.03; mol) over 100; min maintaining the temperature below 5° C. Stir for 1.5; hour maintaining the internal temperature below 10° C. Add an aqueous solution of sodium bisulfite (77.8; mL, 0.377; mol), stir for 5; min and add 12; M hydrochloric acid (390.1; mL, 4.60; mol) over 15; minutes maintaining the temperature below 25° C. Hold the mixture without stirring for 10; min then remove the supernatant, filter the remaining suspension, wash the recovered solid twice with water (200; mL) and dry under vacuum to give the title compound as a yellow solid (91.21; g, 55%). MS (m/z): 325, 327, 329; (M+1).

Provenance & Evidence