1-(Boc-amino)-3-fluorocyclobutane-1-methanol synthesis

Yield:1232365-48-8 39%

Reaction Conditions:

Stage #1: ethyl 1-(tert-butoxycarbonylamino)-3-fluorocyclobutanecarboxylatewith lithium borohydride in tetrahydrofuran at 20;Cooling with ice;
Stage #2: with water;citric acid in tetrahydrofuran;

Steps:

g

To a ice cooled solution of compound BB3-f (0.27 g, 0.001 mol) in dry THF (10 mL) was slowly added a solution of 2M lithium boro hydride (2 mL, 0.004 mol) and the mixture was allowed to warm up to room temperature. The mixture was stirred for 3 h at room temperature. The reaction mixture was quenched with ice water (2 mL) and 5 % citric acid (5 mL) and the crude product was extracted with DCM (2 x 5OmL). The organic layer was washed with brine and dried over anhydrous Na₂SO₄. Solvent was concentrated in vacuum and the crude product was purified by column chromatography (silica gel 60-120 mesh, eluent 15-18 % EtOAc in pet ether) which afforded the title compound as white solid (90 mg, yield 39 %). TLC system: 50% EtOAc in pet ether, R_f= 0.5.

References:

WO2010/70615,2010,A1 Location in patent:Page/Page column 31; 33