Ammonia → HCID 70443569, compound

Participants

Reaction Steps

To a suspension of 4-[6-(2-[2,2,2-trifluoroethyl]guanidino)pyrazin-2-ylthio]butyric acid (0.25 g.) in THF (10 ml) at 0° was added triethylamine (0.082 g.), followed by ethyl chloroformate (0.088 g.) and the mixture was stirred for 30 minutes. A solution of ammonia in THF (5 ml.) was added and the mixture stirred again for 30 minutes, the temperature being allowed to rise to room temperature. The mixture was evaporated in vacuo, aqueous solution bicarbonate (5 ml.) was added and the mixture extracted with EtOAc (2×25 ml.) After drying (MgSO4) the solution was filtered and evaporated in vacuo to give a pale yellow solid. This was purified by medium pressure liquid chromatography on silica eluted with MeOH/CH2Cl2 (1:10 v/v) to give a solid. This was dissolved in EtOAc containing a trace of EtOH and excess of a solution of maleic acid in EtOAc was added. The resulting precipitate was collected by filtration and recrystallised from EtOH to give 4-[ 6-(2-[2,2,2-trifluoroethyl]guanidino)pyrazin-2-ylthio]butyramide maleate, m.p. 171°-172° (30% yield).

Provenance & Evidence