Ethyl Acetate → 4-[4-Amino-3-(3,6-dihydro-2H-thiopyran-4-yl)-phenyl]-piperidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

To a mixture of 4-(4-amino-3-bromo-phenyl)-piperidine-1-carboxylic acid tert-butyl ester (as prepared in Example 13, step (c), 200 mg, 0.563 mmol), 2-(3,6-dihydro-2H-thiopyran-4-yl)-5,5-dimethyl-[1,3,2]dioxaborinane (as prepared in the previous step, 131 mg, 0.619 mmol) and Pd(PPh3)4 (65 mg, 0.056 mmol) in 5 mL of 1,4-dioxane was added 2.0 M aq Na2CO3 solution (2.25 mL, 4.5 mmol). The resulting mixture was stirred at 80° C. for 7 h under Ar, and then cooled to RT. Treated with 50 mL of EtOAc, the mixture was washed with H2O (3×15 mL), brine (20 mL) and dried (Na2SO4). Removal of the solvent under reduced pressure followed by flash chromatography of the residue on silica gel (15-30% EtOAc/hexane) gave 141 mg (67%) of the title compound as a colorless oil. 1H-NMR (CDCl3; 400 MHz): δ 6.91 (dd, 1H, J=8.2, 2.2 Hz), 6.81 (d, 1H, J=2.2 Hz), 6.65 (d, 1H, J=8.2 Hz), 5.91 (m, 1H), 4.22 (br s, 2H), 3.66 (br s, 2H), 3.29-3.31 (m, 2H), 2.87 (dd, 2H, J=5.7, 5.7 Hz), 2.77 (m, 2H), 2.47-2.56 (m, 3H), 1.78 (d, 2H, J=12.6 Hz), 1.50-1.63 (m, 2H), 1.48 (s, 9H). Mass spectrum (ESI, m/z): Calcd. for C21H30N2O2S, 375.2 (M+H). found 375.2.

Provenance & Evidence