(Dimethyl sulfide)trihydroboron → 3-(Aminomethyl)-1-(diphenylmethyl)azetidin-3-ol

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Reaction Steps

A solution of 1-benzhydryl-3-(trimethylsilyloxy)azetidine-3-carbonitrile (example 33, step b) (3.5 g) in THF (50 mL) was treated with borane methylsulfide complex (2M in THF, 20.8 mL) and the resultant mixture heated at 70° C. for 1 hour under nitrogen. The mixture was cooled to room temperature and quenched carefully with methanol (50 mL) followed by treatment with ethylenediamine (2.81 mL). This mixture was stirred at 20° C. for 1 hour and then at 55° C. for 1 hour. The mixture was cooled to room temperature and treated with tetrabutylammonium fluoride (1M in THF, 15.6 mL), then stirred at room temperature for 40 minutes. Solvents were evaporated under reduced pressure and the residue partitioned between ethyl acetate and brine. The organic layer was dried over sodium sulphate, filtered and the solvent evaporated under reduced pressure. The crude product was purified by flash silica chromatography, elution gradient 6 to 7% methanol in dichloromethane with 1% triethylamine. Pure fractions were evaporated to dryness to afford the subtitled compound. Yield 1.95 g.

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