Ammonia → Aminocyclopyrachlor

Participants

Reaction Conditions

Reaction Steps

A 3-L flask was charged with 5,6-dichloro-2-cyclopropyl-4-pyrimidinecarboxylic acid (280 g, 1.2 mol), ammonia (28 wt % in water, 350 g, 5.76 mol) and water (1.26 L). The reaction mixture was heated at 80° C. for 5 h, and excess water (about 600 mL) was removed by distillation at 50° C./9 kPa. After cooling to 20° C., the reaction mixture was acidified to pH 2 with aqueous hydrochloric acid (132 g, 110 mL, 1.32 mol), cooled to 5° C., and filtered. The filtered wet cake was washed with water (2×200 mL) and dried in a vacuum-oven at 55° C. to give about 270 g of the title compound as a monohydrate, which contained 8.3 wt % of water measured by Karl Fischer titration, and decomposed at 152° C. (after crystallization from hot ethanol).

Provenance & Evidence