Triethylamine → 4-Dipentylcarbamoyl-1-(2,2-diphenylacetyl)hexahydro-2-pyrazinecarboxylic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of 79 mg (0.24 mmole) of (±)-1-(diphenylacetyl)piperazine-2-carboxylic acid (from Example 2, Step A) and 2 ml of THF was treated with 49 mg (0.48 mmole) of triethylamine to give a solution which was cooled to 0° C. With stirring a solution of 61 mg (0.25 mmole) of dipentylcarbamoyl chloride (from Step A) in 0.5 ml of THF was added and the solution was briefly warmed to 50° C. and then stirred at 25° C. for 16 hours. The resulting mixture was filtered and the filtrate was concentrated in vacuo to an oil which was dissolved in 0.5 ml of methanol and was chromatographed over an 85×0.9 cm. LH-20 column with 1.7 ml fractions of methanol. Fractions 21-25 were combined and concentrated in vacuo to 70 mg (57%) of oil.

Provenance & Evidence