(2S,5S)-2,5-dimethylpiperazine → N,N-diethyl-4-(3-(tert-butyldimethylsilyloxy)-alpha-((2S,5S)-2,5-dimethyl-1-piperazinyl)benzyl)benzamide

Participants

Reaction Steps

A mixture of 15.65 g (36 mmol) of N,N-diethyl-4-(3-(t-butyldimethylsilyloxy)-α-chlorobenzyl)benzamide, prepared as described in Example 11, 7.22 g (65 mmol) of (+)-(2S,5S)-2,5-dimethylpiperazine, prepared from L-Ala-L-Ala-diketopiperazine (Bachem Chemicals, Philadelphia, Pa.) as described by Jung and Rohloff (J. Org. Chem. 50, 4909-13 (1985)), and 3 mL of toluene was heated as in Example 1. The product was purified by chromatography on silica gel (Waters Prep 500 with dichloromethane containing 1% ethanol and 0.1% triethylamine) to give 4.06 g (22%) of N,N-diethyl-4-(3-(tert-butyldimethylsilyloxy)-α-((2S,5S)-2.5-dimethyl-1-piperazinyl)benzyl)benzamide as a beige foam.

Provenance & Evidence