Sodium hydride → 4-(3,5-Di-tert-butyl-4-hydroxy-phenylsulfanyl)-piperidine-1-carboxylic acid tert-butyl ester

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Reaction Conditions

Reaction Steps

To 4-methanesulfonyloxy-piperidine-1-carboxylic acid tert-butyl ester (Ex. 3a, 22 g) and 2,6-di-tert-butyl-4-mercapto-phenol (16.58 g) in 300 mL of DMF was added sodium hydride (3.8 g, 60% in oil). The mixture was stirred at 60° C. for 20 h and then poured onto ice and quenched with 1 N HCl. The gooey solid obtained via filtration was dissolved in Ethyl acetate, dried over Na2SO4, and concentrated. The crude product was dissolved in a minimal amount of diethyl ether and triturated with hexanes to give 4-(3,5-di-tert-butyl-4-hydroxy-phenylsulfanyl)-piperidine-1-carboxylic acid tert-butyl ester as an off-white solid (16 g), mp 151-152° C. 1H-NMR (400 MHz, CDCl3): δ 7.28 (s, 2H), 5.28 (s, 1H), 3.98 (s, 2H), 3.03-2.96 (m, 1H), 2.87 (t, 2H, J=10.4 Hz), 1.91-1.87 (m, 2H), 1.54-1.48 (m, 2H), 1.44 (s, 9H), 1.43 (s, 18H). HRMS (ESI) Calcd. for C24H39NO3S: 421.2651 (M+). Found: 421.2656. Anal. Calcd. for C24H39NO3S, C, 68.37; H, 9.32; N, 3.32; S, 7.60. Found: C, 68.20; H, 9.42; N, 3.23; S, 7.77.

Provenance & Evidence