2,6-Di-tert-butyl-4-mercaptophenol → 4-(3,5-Di-tert-butyl-4-hydroxy-phenylsulfanyl)-4-ethoxycarbonylmethyl-piperidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A suspension of 2,6-di-tert-butyl-4-mercapto-phenol (1.2 g, 5.2 mmol) and 4-ethoxycarbonylmethylene-piperidine-1-carboxylic acid tert-butyl ester (1.2 g, 4.4 mmol) in 5 mL of piperidine was degassed and then heated to 90° C. for 15 h. The reaction was cooled to room temperature, toluene (10 mL) was added, and the mixture was concentrated under reduced pressure. The residue obtained was diluted with ethyl acetate (40 mL), washed with 1 N HCl (2×30 mL) and water (40 mL), dried over Na2SO4, and concentrated under reduced pressure. Chromatography (2-20% ethyl acetate/hexanes) afforded 4-(3,5-di-tert-butyl-4-hydroxy-phenylsulfanyl)-4-ethoxycarbonylmethyl-piperidine-1-carboxylic acid tert-butyl ester as a foamy solid (2.1 g, 94%). ESI/CI-MS m/z 506 ([M−H]−).

Provenance & Evidence