2-Methyl-3-butyn-2-ol → HCID 86693503, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of -(difluoromethyl)-8-fluoro-9-iodo-3,4,5,6-tetrahydro-4,6-methanobenzo[3,4]cyclohepta[1,2-d]imidazole-2-carboxamide (12 mg at 80% purity LCMS-UV215) in piperidine (0.5 mL) was introduced 2-methyl-3-butyn-2-ol (12 mg, 0.14 mmol) and copper(I) iodide (0.3 mg, 0.001 mmol). The solution was de-oxygenated by nitrogen bubbling for five minutes, then tetrakis(triphenylphosphine)palladium(0) (0.6 mg, 0.001 mmol) added and bubbling continued for a further two minutes. The pressure tube was closed under an atmosphere of nitrogen and the reaction mixture warmed to 40° C. for 2 hr. After evaporation of the reaction mixture in vacuo, the residue was suspended in ethyl acetate (20 mL) and washed with saturated aqueous sodium bicarbonate (2×7 mL), water (2×7 mL) and brine (7 mL). The organic extract was dried over sodium sulfate, filtered, and the filtrate adsorbed onto silica gel in vacuo. Partial purification of the dry-loaded material by silica gel flash column chromatography (eluent: heptane/ethyl acetate gradient) was followed by suspension of the product in acetonitrile/water (3:1, 0.4 mL). Filtration furnished the title compound (4.5 mg, 0.011 mmol, 6% over 3 steps) as a colorless solid: 1H NMR (500 MHz, CDCl3) δ 1.67 (s, 6H), 1.73 (d, J=11.35 Hz, 2H), 2.93-3.04 (m, 2H), 3.60 (td, J=7.96, 3.31 Hz, 1H), 3.84-3.92 (m, 1H), 5.56 (br. s., 1H), 6.87 (d, J=10.09 Hz, 1H), 7.42 (br. s., 1H), 8.40 (d, J=7.57 Hz, 1H), 8.75 (t, J=58.40 Hz, 1H); M+H=390.

Provenance & Evidence