1,2-Dichloroethane → tert-butyl (2R,5R)-4-benzyl-5-(hydroxymethyl)-2-methylpiperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of (2R,5R)-2-hydroxymethyl-5-methyl-piperazine-1,4-dicarboxylic acid 1-benzyl ester 4-tert-butyl ester (3.48 g, 15.1 mmol), benzaldehyde (1.76 g, 16.6 mmol), sodium triacetoxyborohydride (3.84 g, 18.1 mmol) and 1,2-dichloroethane (30 mL) was stirred at 20° C. for 18 h, then partitioned between saturated aqueous NaHCO3 (150 mL) and DCM (3×50 mL). Combined organic extracts were dried (Na2SO4) then evaporated in vacuo to give an oil. Chromatography (SiO2, 0-30% EtOAc in petrol) gave the title compound (4.588 g, 74%) as a colourless solid. MS: [M+H]+=321.

Provenance & Evidence