Reaction #52566

Reaction equation

HCl

BH3.THF

5-nitro-salicylic acid

Methyl tert-butyl ether

BH3.THF

→

2-hydroxymethyl-4-nitrophenol

Yield 76.2%

Solvents

THF

Conditions

Workup

1. 1
   TemperatureAfter a few milliliters, the reaction mixture was cooled with ice
2. 2
   TemperatureThe clear brown solution was warmed to room temperature
3. 3
   OtherDuring this time a precipitate formed
4. 4
   workup.STIRRINGstirring
5. 5
   workup.WAITwas continued overnight
6. 6
   TemperatureThe mixture was cooled to 5° C.
7. 7
   Otherthe phases were separated
8. 8
   Extractionthe aqueous layer was extracted with MTBE (2×70 mL)
9. 9
   DryingThe combined organic layers were dried over MgSO4 (10 g)
10. 10
    Filtrationfiltered
11. 11
    Otherevaporated
12. 12
    Otherto give 10.5 g of a pale ochre solid
13. 13
    OtherThis solid was recrystallized from 65 mL toluene

Procedure

To a BH3.THF solution (110 mL, 1M, 110 mmoles) was added dropwise a solution of 5-nitro-salicylic acid (10.0 g, 54.6 mmoles) in 930 mL THF. After a few milliliters, the reaction mixture was cooled with ice to maintain a temperature of about 15° C. The clear brown solution was warmed to room temperature and stirred for an additional 7 hours. During this time a precipitate formed. BH3.THF (20 ml, 20 mmoles) was added and stirring was continued overnight. The mixture was cooled to 5° C. and carefully hydrolyzed with 1 M HCl (100 mL). Methyl tert-butyl ether (MTBE) (100 mL) was added, the phases were separated and the aqueous layer was extracted with MTBE (2×70 mL). The combined organic layers were dried over MgSO4 (10 g), filtered and evaporated to give 10.5 g of a pale ochre solid. This solid was recrystallized from 65 mL toluene to give 7.033 g (76%) of 2-hydroxymethyl-4-nitrophenol as a pale ochre solid.

Source