Isopropanol → (3-Amino-4-fluorophenyl)methanol

Participants

Reaction Steps

A flask equipped with overhead stirrer was charged with 4-fluoro-3-nitrobenzyl alcohol (20 g, 0.117 mol) and 200 mL of 5:1 isopropanol: water. Ammonium chloride (62 g, 1.17 mol) was added followed by iron filings (65 g, .17 mol). The mixture was stirred at 70 C for 1.5 H when it was shown to be complete by LC-MS. The liquid was decanted and the solids were washed with additional isopropanol:water. The isopropanol was removed and the residue was diluted with 0.5 N HCl and was extracted with ethyl acetate. The aqueous layer was brought to pH 12-14 with 2.5 N NaOH and was extracted with ethyl acetate. The organic layer was dried with anhydrous Na2SO4 and concentrated in vacuo. 3-Amino-4-fluorophenyl methanol was isolated as a brown solid (4.5 g, 27%) and was used without further purification. LC/MS, tr=2.40 minutes (5 to 95% acetonitrile/water over 8 minutes at 1 ml/min with detection 254 nm, at 50° C.). ES-MS m/z 142 (M+H). ES-HRMS m/z 142.0692 (M+H calcd for C7H8FNO requires 142.0663). Step 2 Preparation of 1-[2-fluoro-5-(hydroxymethyl)phenyl]-4-hydroxy-6-methylpyridin-2(1H)-one

Provenance & Evidence