Aluminium lithium hydride → (S)-1-Amino-2-(5-bromo-2-fluoro-phenyl)-propan-2-ol

Participants

Reaction Conditions

Reaction Steps

To a suspension of LiAlH4 (4.65 g, 122 mmol) in THF (250 ml) was added under argon at 0-5° C. a solution of (S)-1-azido-2-(5-bromo-2-fluoro-phenyl)-propan-2-ol (33.4 g, 122 mmol) dissolved in THF (150 ml) over a period of 30 min. After stirring for 1 h at 0-5° C., the reaction was quenched by careful addition of water (4.7 ml), 4 N NaOH (4.7 ml) and water (14.1 ml) and stirred again for 3 h at 25° C. The white suspension was dried with MgSO4, filtered and concentrated. The solidified product was re-crystallized from TBME-hexane to provide the title compound as beige crystals: 98% ee (Chiralpak AD-H hexane-EtOH 75-25+0.05% NEt3); TLC (CH2Cl2-MeOH 10:1) Rf=0.10; HPLC RtH5=0.558 min; ESIMS: 248, 250 [(M+H)+]; 1H NMR (360 MHz, CDCl3): δ 7.76 (dd, 1H), 7.25 (m, 1H), 6.82 (dd, 1H), 4.16 (br s, 1H), 3.19 (d, 1H), 2.72 (d, 1H), 1.44 (s, 3H), 0.95 (br s, 2H).

Provenance & Evidence