[Cl:1][C:2]1[CH:9]=[C:8]([F:10])[C:7]([N+:11]([O-:13])=[O:12])=[CH:6][C:3]=1[CH:4]=[O:5].[BH4-].[Na+].Cl>O1CCCC1>[Cl:1][C:2]1[CH:9]=[C:8]([F:10])[C:7]([N+:11]([O-:13])=[O:12])=[CH:6][C:3]=1[CH2:4][OH:5]To a solution of 10.8 g (0.053 mole) of 2-chloro-4-fluoro-5-nitrobenzaldehyde in 100 ml of tetrahydrofuran was added 0.50 g (0.013 mole) of sodium borohydride portionwise. The reaction mixture was stirred for one hour after which dilute hydrochloric acid was added to destroy unreacted sodium borohydride. To this mixture was added 200 ml of methylene chloride, and the phases were separated. The organic phase was washed three times with water, dried over anhydrous magnesium sulfate, and filtered. The solvent was evaporated from the filtrate under reduced pressure, leaving a residue weighing 10.7 g. This residue was combined with 1.67 g of a similar residue another run of the same reaction. The combined residues were passed through a silica gel column, eluting with ethyl acetate/heptane (1/4) to yield 7.7 g of 2-chloro-4-fluoro-5-nitrobenzyl alcohol as a yellow solid.
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