反应详情

To a solution of (E)-N-((1,5-dimethyl-1H-pyrazol-4-yl)methylene)-2-methylpropane-2-sulfinamide (Step A5A) (600 mg, 2.64 mmol) in CH2Cl2 (15 ml) was added a 3.0 M solution of EtMgBr in ether (1.76 ml, 5.28 mmol) at −48° C. under nitrogen. After being stirred for 120 min, the reaction mixture was allowed to warm to rt slowly over 2 h and further stirred for 15 h at rt. The reaction was quenched by addition of sat. NH4Cl aq., diluted with water, and the aqueous layer was extracted with CH2Cl2 3 times. The combined organic extracts were dried over Na2SO4 and concentrated in vacuo. The crude product was purified by silica gel column chromatography (CH2Cl2: MeOH=50:1 to 20:1) to give the desired product as a pale yellow oil (650 mg, >96% yield). 1H NMR (270 MHz, CDCl3) δ 0.87 (3H, t, J=5.4 Hz), 1.17 (9H, s), 1.77-1.85 (2H, m), 2.25 (3H, s), 3.78 (3H, s), 3.31 (1H, brs), 4.16-4.22 (1H, m), 7.31 (1H, s).

1. stirringfurther stirred for 15 h at rt
2. customThe reaction was quenched by addition of sat. NH4Cl aq.
3. additiondiluted with water
4. extractionthe aqueous layer was extracted with CH2Cl2 3 times
5. dry with materialThe combined organic extracts were dried over Na2SO4
6. concentrationconcentrated in vacuo
7. customThe crude product was purified by silica gel column chromatography (CH2Cl2: MeOH=50:1 to 20:1)