Water → D-Tartrate

Participants

Reaction Conditions

Reaction Steps

To a solution of 8a-pyridin-2-ylmethyl-2-(2,2,2-trifluoro-ethyl)-tetrahydro-imidazo[1,5-a]pyrazine-1,3-dione (prepared according to the method described in Step. 6, 106 g, 0.325 mol) in acetone (2120 mL) and water (212 mL) was added D-tartaric acid (48.46 g, 0.325 mol). White precipitate formed and it was granulated for 3 hours. The solids were collected by suction filtration and washed with acetone. The solvent damp solids were placed in acetone (1000 mL) and stirred at 56° C. overnight. The solids were collected by suction filtration the next morning and dried to give 56 g of the chiral title compound as the D-tartrate salt (73% yield of theory). Chiral HPLC showed an optical purity of 98:2.

Provenance & Evidence