Reacción #75923

Ecuación de reacción

Water

sodium borohydride

3,5-difluoro-4-(methylthio)-benzaldehyde

HCl

→

[3,5-difluoro-4-(methylthio)-phenyl]methanol

Rendimiento 78.5%

Disolventes

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   Extracciónthe mixture extracted with dichloromethane (1×500 mL, 1×100 mL)
2. 2
   LavadoThe combined extracts were washed once with water
3. 3
   Secadodried with magnesium sulfate
4. 4
   Concentraciónconcentrated
5. 5
   OtroPurification by silica gel chromatography
6. 6
   Lavadoeluting product with 60% ethyl acetate in hexanes

Procedimiento

To a solution of 3,5-difluoro-4-(methylthio)-benzaldehyde (31.3 g, 0.166 mol) in anhydrous THF (200 mL) cooled with a cold water bath was added sodium borohydride (1.6 g, 0.042 mol) in portions over 30 minutes. After stirring 1 hour at room temperature, excess dilute HCl was added, until gas evolution ceased. Water (600 mL) was added and the mixture extracted with dichloromethane (1×500 mL, 1×100 mL). The combined extracts were washed once with water, dried with magnesium sulfate, and concentrated. Purification by silica gel chromatography using 3% ethyl acetate/10% dichloromethane in hexanes initially, and eluting product with 60% ethyl acetate in hexanes gave [3,5-difluoro-4-(methylthio)-phenyl]methanol as a light yellow liquid (24.8 g, 78%). 1H NMR (CDCl3/400 MHz) 6.88-6.93 (m, 2H), 4.65 (s, 2H), 2.42 (s, 3H). HRMS m/z 190.0266 (M+H+, calcd 190.0264).

Fuente