Sodium borohydride → 4-Chloro-2,6-dimethylbenzyl alcohol

Temperature

0 °C

Dissolve 4-chloro-2,6-dimethyl benzaldehyde (5.0 g, 168.64 g/mol) in 100 mL dry MeOH. Cool to 0° C. while stirring under N2. Portionwise add powdered NaBH4 (0.76 g, 37.85 g/mol) over 5 min. Stir at 0° C. for 2 h, monitoring by TLC until aldehyde consumed, then evaporate to a yellow oil. Add H2O (50 mL) and bring to pH 7.0 by addition of saturated NH4Cl. Extract the neutral aqueous layer with CH2Cl2 (3×75 mL) and dry the pooled organic layers over Na2SO4. Filter and concentrate to a yellow oil. Flush through a pad of silica to remove baseline material, then evaporate to a yellow solid (3.0 g) which can be used without further purification. LCMS=171.6 (MH+), 169.6 (M−).

1. stirringStir at 0° C. for 2 h
2. custommonitoring by TLC until aldehyde consumed
3. customevaporate to a yellow oil
4. additionAdd H2O (50 mL) and bring to pH 7.0 by addition of saturated NH4Cl
5. extractionExtract the neutral aqueous layer with CH2Cl2 (3×75 mL)
6. dry with materialdry the pooled organic layers over Na2SO4
7. filtrationFilter
8. concentrationconcentrate to a yellow oil
9. customFlush through a pad of silica
10. customto remove baseline material
11. customevaporate to a yellow solid (3.0 g) which
12. customcan be used without further purification

ORD record

ord-4d8a3256ddf647b881ebd1bce13721a3

Source dataset

uspto-grants-2002_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06476038B1