Ethyl orthoformate → 3-((3S,9aS)-8-(2-(2-(1H-tetrazol-1-yl)pyrimidin-5-yl)-2,2-difluoroacetyl)octahydropyrazino[2,1-c][1,4]oxazin-3-yl)-6-fluoro-2-methylbenzonitrile

Participants

Reaction Steps

Trimethylsilyl trifluoroacetate (23.8 μL, 0.137 mmol) was added to a suspension of 3-((3S,9aS)-8-(2-(2-aminopyrimidin-5-yl)-2,2-difluoroacetyl)octahydropyrazino[2,1-c][1,4]oxazin-3-yl)-6-fluoro-2-methylbenzonitrile (36.1 mg, 0.081 mmol) in ethyl acetate (735 μL). The mixture was stirred for 5 min at room temperature and triethyl orthoformate (23.67 μL, 0.142 mmol) was added. After stirring for 5 more min at room temperature, azidotrimethylsilane (16.91 μL, 0.129 mmol) was added. The mixture was stirred at room temperature overnight. The reaction mixture was diluted with methanol and purified on mass-directed preparative HPLC. Appropriate fractions were collected and solvent was removed under reduced pressure. The residue was converted to hydrochloric acid salt. LC/MS: [(M+1)]+=500.0; 1H NMR (500 MHz, DMSO-d6) δ 10.33 (s, 1H), 9.35 (s, 2H), 7.85-7.94 (m, 1H), 7.43-7.54 (m, 1H), 5.14-5.27 (m, 1H), 4.01-4.60 (m, 5H), 3.13-3.95 (m, 6H), 2.53 (s, 3H).

Provenance & Evidence