反应详情

温度

-78 °C

t-Butyl 2-(1-hydroxymethyl-2-(4-methoxyphenyl)ethylamino)-3-methylbutyrate (2.49 g; 7.4 mmol) was dissolved in CH2Cl2 (180 ml). The reaction solution was cooled to −78° C. Then pyridine (3 ml; 37 mmol) was added and subsequently thionyl chloride (0.64 ml; 8.88 mmol) was added dropwise. The reaction mixture was stirred for 1 h, during which the temperature was allowed to reach 0° C. It was taken up in CH2Cl2 and washed with aqueous HCl (1%; 2×) and NaHCO3 solution. The organic phase was dried over Na2SO4 and concentrated in a rotary evaporator. The crude product was purified by filtration through silica gel (100 g). t-Butyl 2-(4-(4-methoxybenzyl)-2-oxo-(1,2,3)oxathiazolidin-3-yl)-3-methylbutyrate (2.35 g; 0.61 mmol) was obtained as a dark yellow oil. MS: 384.20 (M+H); Rt: 1.76 min (method: gradient 0 min 96% H2O (0.05% TFA) 2.0 min 95% acetonitrile, 95% acetonitrile to 2.4 min, 4% acetonitrile 2.45 min; flow rate 1 ml/min; column 0.4 μL (YMC J'sphere ODS H80 20X2 1.4μ); 30° C.)

1. customto reach 0° C
2. washwashed with aqueous HCl (1%; 2×) and NaHCO3 solution
3. dry with materialThe organic phase was dried over Na2SO4
4. concentrationconcentrated in a rotary evaporator
5. filtrationThe crude product was purified by filtration through silica gel (100 g)