Hydrochloric Acid → Tert-butyl 4-(4-chloro-1,2,5-thiadiazol-3-yl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

1-Boc-piperazine (30.2 g, 165 mmol) was dissolved in DMF (30.0 mL) and heated to 100° C. 3,4-Dichloro-1,2,5-thiadiazole (7.5 mL, 80 mmol) was added dropwise with stirring and the mixture heated at 100° C. for 5.5 h. The reaction mixture was diluted with H2O and the pH adjusted to 2.0 with 1N HCl. The resulting solids were filtered, washed with H2O and dried under vacuum to give 20.1 g (83%) of 4-(4-chloro-[1,2,5]thiadiazol-3-yl)-piperazine-1-carboxylic acid tert-butyl ester as a tan solid. 1H NMR (DMSO-d6) 3.48 (m, 4H), 3.36 (m, 4H), 1.42 (s, 9H) ppm. LC-MS (MH+)=205 (-Boc).

Provenance & Evidence