(4R)-2-Hydroxy-5,5-dimethyl-4-phenyl-1,3,2-dioxaphosphorinan 2-oxide → (-)-(cis)-7-bromo-8-fluoro-1,3,4,14b-tetrahydro-2H-dibenzo[b,f]pyrido[1,2-d][1,4]oxazepin-1-amine (4S)-2-hydroxy-5,5-dimethyl-4-phenyl-1,3,2-dioxaphosphorinane 2-oxide

Participants

Reaction Conditions

Reaction Steps

To a solution of (±)-(cis)-7-bromo-8-fluoro-1,3,4,14b-tetrahydro-2H-dibenzo[b,f]pyrido[1,2-d][1,4]oxazepin-1-amine (18.58 g, 51.18 mmol) in 300 mL of CH2Cl2 and 60 mL of 2-propanol at 50° C. was added a warm solution of (+)-phencyphos (6.19, 25.59 mmol) in CH2Cl2 (300 mL) and 2-propanol (75 mL). The mixture was heated at 86° C. About 500 mL of CH2Cl2 was removed by careful evaporation, and 310 mL of 2-propanol was added; the mixture was then further concentrated until a final weight of ca. 250 g, and then gradually cooled down to 35° C. After 1 h, the formed crystals were collected by filtration, washed with 2-propanol and dried to yield 12.7 g of crude product (e.e. =95%). This compound was further recrystallized from methanol:CH2Cl2:2-propanol (7:5:2) to give the title compound (12.3 g, 39%, e.e.=99.8%).

Provenance & Evidence