反应详情

温度

65 °C

To a solution of 1-methyl-1H-pyrazole-4-carbaldehyde (2.2 g, 20 mmol) in THF (50 mL) was added (R)-2-methylpropane-2-sulfinamide (4.8 g, 40 mmol) and Ti(OEt)4 (9.2 g, 40 mmol). The reaction mixture was heated at 65° C. for 14 h. After cooling, the mixture was poured into water. The solid was filtered off, and the filtrate was extracted with EtOAc. The organic layer was concentrated and purified by SiO2 chromatography eluting with petroleum ether/EtOAc (5:1) to afford 4.0 g (83%) of (R,E)-2-methyl-N-((1-methyl-1H-pyrazol-4-yl)methylene)propane-2-sulfinamide (46). LCMS (ESI) m/z: 214.1 [M+11]+.

1. temperatureAfter cooling
2. filtrationThe solid was filtered off
3. extractionthe filtrate was extracted with EtOAc
4. concentrationThe organic layer was concentrated
5. custompurified by SiO2 chromatography
6. washeluting with petroleum ether/EtOAc (5:1)