Sodium cyanoborohydride → 4-(1-Acetylazetidin-3-yl)-7-chloro-6-fluoro-2-methyl-9-(2-methyl-1,3-dioxolan-2-yl)-4,5-dihydro-1,4-benzoxazepin-3(2H)-one

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Reaction Steps

A solution of ethyl 2-[4-chloro-3-fluoro-2-formyl-6-(2-methyl-1,3-dioxolan-2-yl)phenoxy]propanoate (392 mg, 1.09 mmol) in methanol (21 mL) was treated with sodium cyanoborohydride (171 mg, 2.72 mmol) followed by 1-acetylazetidin-3-amine hydrochloride (360 mg, 2.39 mmol) and stirred at room temperature overnight. The reaction mixture was quenched with acetic acid (200 μL) and concentrated in vacuo. The residue was diluted with toluene (60 mL) and heated at 110° C. for 2 h. The solvent was concentrated in vacuo, and the residue was purified via preparative LCMS (XBridge C18 column, eluting with a gradient of acetonitrile/water containing 0.1% ammonium hydroxide, at flow rate of 60 mL/min) to give the desired product (142 mg, 32%) as a mixture of enantiomers. LCMS calculated for C19H23ClFN2O5(M+H)+: m/z=413.1; found: 413.1.

Provenance & Evidence