2,3-Dihydroxybutanedioic Acid → 2,3-Dihydroxybutanedioate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 3 parts of 3-(aminocarbonyl)-4-[4,4-bis(4-fluorophenyl)butyl]-N-(2,6-dimethylphenyl)-1-piperazineacetamide in 24 parts of ethanol was added a solution of 0.94 parts of (+)-2,3-dihydroxybutanedioic acid in 24 parts of ethanol. The whole was evaporated and the oily residue was dissolved in warm 4-methyl-2-pentanone. After cooling to 0° C., the product was filtered off and dissolved in 2-propanone. 0.2 Parts of 2,3-dihydroxybutanedioic acid were added and upon the addition of 4-methyl-2-pentanone, the product was precipitated. It was filtered off and dried, yielding 0.8 parts of (+)-3-(aminocarbonyl)-4-[4,4-bis(4-fluorophenyl)butyl]-N-(2,6-dimethylphenyl)-1-piperazineacetamide [R-(R*,R*)]-2,3-dihydroxybutanedioate (2:3) monohydrate; mp. 78.1° C. (compound 173).

Provenance & Evidence