Diisopropylethylamine → 1-[3-chlorophenyl(phenyl)carbamoyl]-4-dipentylcarbamoyl-(2S)-hexahydro-2-pyrazinecarboxylic acid

関与物質

反応条件

反応手順

To a suspension of 1.05 g (2.3 mmole) of (S)-1-[N-(3-chlorophenyl)-N-phenylcarbamoyl]piperazine-2-carboxylic acid hydrobromide (from Step C) in 20 ml of methylene chloride was added 1.23 g (9.5 mmole) of N,N-diisopropylethylamine followed by the dropwise addition of a solution of 523 mg (2.38 mmole) of dipentylcarbamoyl chloride (from Example 3, Step A) in 5 ml of methylene chloride. After stirring 24 hours at 25° C., the solution was extracted with 2N HCl, then H2O and dried over MgSO4. The dried methylene chloride solution was concentrated in vacuo and the residue was dissolved in isopropyl ether and was diluted with petroleum ether (bp. 30°-60° C.) until cloudy. The oil which precipitated was then decanted, redissolved in isopropanol and concentrated in vacuo to yield 464 mg (36%) of (S)-1-[N-(3-chlorophenyl)-N-phenylcarbamoyl]-4-(dipentylcarbamoyl)piperazine-2-carboxylic acid as a glassy solid; TLC showed a single spot, Rf 0.75 (Anal tech SGF plates developed with isoamyl alcohol:acetone:water [5:2:1]).

情報源と証拠