1-Methylpiperazine → HCID 18639812, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 3-acetylmercapto-6-methyl-4-[[[1-(S)-[(methylamino)carbonyl]-2-(4-methoxyphenyl)ethyl]amino]-carbonyl]heptanoic acid (E5, Isomer A; 226 mg, 0.5 mmol), N,N1 -dicyclohexylcarbodiimide (103 mg, 0.5 mmol), 1-hydroxybenzotriazole (76 mg, 0.5 mmol) and N-methylpiperazine (0.05 ml, 0.5 mmol) in dichloromethane (8 ml) was stirred at 5° C. for 1 h, then at room temperature overnight. After cooling, the precipitated solid was filtered off. The solution was diluted with dichloromethane and extracted with 0.25M citric acid. The extracts were washed with dichloromethane then basified with 10% sodium carbonate, and extracted with ether. The ether extracts were washed with brine, dried (Na2SO4) and evaporated in vacuo. Trituration of the oily residue with ether, followed by recrystallisation of the resulting solid from ethyl acetate/hexane gave the title compound as a single isomer (Isomer A), 98 mg (37%) mp 133°-138° C.

Provenance & Evidence