反应详情

2-(1,1-dimethylethylsulfinamido)-N′-hydroxy-2-methylpropanimidamide (1.0 g, 4.5 mmol) in triethoxymethane (7.5 ml, 45 mmol) was treated with AcOH (7.5 ml) at rt. The reaction was allowed to stir at rt for 16 h. The reaction was then concentrated to dryness azeotroping with toluene 3×. The resulting yellow oil was purified on silica gel (Biotage, EtOAc/hexanes gradient) to give the expected product N-(2-(1,2,4-oxadiazol-3-yl)propan-2-yl)-2-methylpropane-2-sulfinamide (750 mg, 3.24 mmol, 72% yield) consistent by LCMS and NMR. LC-MS retention time: 0.987 min; m/z (MH+): 232. LC data was recorded on a Shimadzu LC-10AS liquid chromatograph equipped with a Phenomenex-Luna 3u C18 2.0×30 mm column using a SPD-10AV UV-Vis detector at a detector wave length of 220 nM. The elution conditions employed a flow rate of 1 mL/min, a gradient of 100% solvent A/0% solvent B to 0% solvent A/100% solvent B, a gradient time of 2 min, a hold time of 1 min, and an analysis time of 3 min where solvent A was 10% acetonitrile/90% H2O/0.1% trifluoroacetic acid and solvent B was 10% H2O/90% acetonitrile/0.1% trifluoroacetic acid. MS data was determined using a Micromass Platform for LC in electrospray mode. 1H NMR (400 MHz, DMSO-d6) δ 9.51 (s, 1H), 5.54 (s, 1H), 1.65 (s, 3H), 1.59 (s, 3H), 1.08 (s, 9H).

1. concentrationThe reaction was then concentrated to dryness
2. customazeotroping with toluene 3×
3. customThe resulting yellow oil was purified on silica gel (Biotage, EtOAc/hexanes gradient)