Methyl Acetate → Methyl 3-(4-butoxyphenyl)-3-((tert-butylsulfinyl)amino)butanoate

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of diisopropylamine (3.86 mL, 27.1 mmol) in THF (40 mL) at −78° C. was added n-butyllithium (22.57 mL, 27.1 mmol) dropwise. The reaction was slowly warmed up to −20° C. and stirred for 45 min. The reaction was cooled to −78° C. and methyl acetate (2.006 g, 27.1 mmol) was added dropwise. After 30 min, chlorotitanium triisopropoxide (8.09 mL, 33.8 mmol) in THF (40 mL) was added dropwise. The reaction was stirred at −78° C. for 1 h. Intermediate 107A (4 g, 13.54 mmol) in THF (15 mL) was added dropwise and the reaction was stirred at −78° C. for 2 h. The reaction was quenched by addition of sat'd NH4Cl solution and stirred vigorously while warmed to rt. The mixture was filtered through Celite® and washed with EtOAc. The filtrate was washed with H2O, brine, dried over MgSO4, filtered and concentrated. The crude product was purified by silica gel chromatography (220 g silica gel, eluted with EtOAc in hexanes) to yield the desired product (4.33 g, 87%) as a light yellow oil. LCMS Anal. Calc'd for C19H31NO4S 369.20, found [M+H] 370.2. 1H NMR (500 MHz, CDCl3) δ 7.31 (d, J=8.80 Hz, 2H), 6.85 (d, J=8.80 Hz, 2H), 3.95 (t, J=6.46 Hz, 2H), 3.62 (s, 3H), 2.05 (s, 2H), 1.74-1.80 (m, 2H), 1.74 (s, 3H), 1.44-1.54 (m, 2H), 1.29 (s, 9H), 0.98 (t, J=7.43 Hz, 3H).

Provenance & Evidence