Triethylamine → N-Boc-3-mesyloxypiperidine

Participants

Reaction Steps

To a stirred solution of the title compound of Example 1 (44.3 g, 220 mmol) and Et3N (61.4 mL, 440 mmol, 2 eq) in THF (250 mL) was added dropwise at rt (maintained by cooling from an ice bath), methanesulfonyl chloride (27.77 g, 242 mmol, 1.1 eq). The reaction mixture was stirred for 1 h at rt when TLC (solvent system C) indicated completion. The precipitated Et3N·HCl was removed by filtration and the filter cake was washed with 50 mL of THF. The combined filtrate and washings were evaporated in vacuo to give the crude product as a yellow oil. This was dissolved in EtOAc/hexanes (1:2) and passed through a pad of silica gel eluting with ethyl acetate/hexanes (1:3). Evaporation of the filtrate afforded the product as a pale yellow oil (59.1 g, 96%) which crystallized on standing. Recrystallization from EtOAc/hexane (1:10) afforded an analytically pure sample: mp 69°-70° C.; 1H-NMR (CDCl3) ∂4.72 (m, 1H), 3.63 (m, 2H), 3.46 (m, 1H), 3.32 (m, 1H), 3.05 (s, 3H), 1.75-2.06 (complex m, 4H), 1.46 (s, 9H); CIMS (MH+ calcd for C11H21NO5S): 280. Found (MH+): 280; Anal. (calcd for C11H21NO5S): C, H, N.

Provenance & Evidence