[Synthesis]
1. 3-Chloro-5-nitrobenzoic acid (5.00 g, 24.8 mmol, ABCR GmbH & CO.KG) was dissolved in THF (48 mL) at 0 °C and stirred until homogeneous.
2. To the above solution, a THF solution of 1 M borane-THF complex (99.2 mL, 99.2 mmol) was slowly added, keeping the temperature at 0 °C.
3. The reaction mixture was gradually warmed to room temperature and the reaction was stirred overnight.
4. Upon completion of the reaction, MeOH was slowly added to the stirred mixture under ice bath cooling to quench the reaction.
5. The reaction mixture was diluted with ethyl acetate and washed sequentially with 1N aqueous sodium hydroxide and saturated aqueous sodium chloride.
6. The organic phase was separated, dried over anhydrous sodium sulfate, filtered and concentrated.
7. The residue was purified by column chromatography (eluent: hexane/ethyl acetate, gradient from 50% to 100%) to give pure 3-chloro-5-nitrobenzyl alcohol (4.22 g, 22.5 mmol). 8. The structure of the product was determined by NMR.
8. The structure of the product was confirmed by NMR (400 MHz, CDCl3, 300 K): δ = 8.13 (m, 2H), 7.71 (s, 1H), 4.81 (m, 2H), 2.00 (br, 1H). |