Trifluoroacetic acid → N-[2-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]ethyl]methanesulfonamide
Reaction equation
FC(F)(F)C(O)=O.C(OC(=O)[N:14]([S:32]([CH3:35])(=[O:34])=[O:33])[CH2:15][CH2:16][C:17]1[CH:22]=[CH:21][C:20]([B:23]2[O:27][C:26]([CH3:29])([CH3:28])[C:25]([CH3:31])([CH3:30])[O:24]2)=[CH:19][CH:18]=1)(C)(C)C.[OH-].[Na+]>ClCCl>[CH3:28][C:26]1([CH3:29])[C:25]([CH3:30])([CH3:31])[O:24][B:23]([C:20]2[CH:19]=[CH:18][C:17]([CH2:16][CH2:15][NH:14][S:32]([CH3:35])(=[O:34])=[O:33])=[CH:22][CH:21]=2)[O:27]1Participants
Procedure
Trifluoroacetic acid (10 mL) was added to a 0° C. solution of tert-butyl(methylsulfonyl){2-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]ethyl}carbamate (from the previous step, assumed 19.7 mmol) in dichloromethane (100 mL). The reaction mixture was allowed to warm to room temperature and stir for 18 hours. It was then cooled to 0° C. and brought to pH 10.5 with a 4N aqueous sodium hydroxide solution. The organic layer was washed with saturated aqueous sodium chloride solution, dried over magnesium sulfate, filtered and concentrated in vacuo. The residue was purified via silica gel chromatography (Gradient: 0% to 5% methanol in dichloromethane) to provide the title compound as an off-white solid. Yield: 2.5 g, 7.7 mmol, 39% over two steps. LCMS m/z 326.1 (M+1). 1H NMR (400 MHz, CDCl3) δ 1.35 (s, 12H), 2.84 (s, 3H), 2.90 (t, J=6.8 Hz, 2H), 3.42 (dt, J=6.6, 6.6 Hz, 2H), 4.18 (br t, J=6 Hz, 1H), 7.23 (d, J=8.1 Hz, 2H), 7.78 (d, J=8.1 Hz, 2H).
Workup
- temperatureIt was then cooled to 0° C.
- washThe organic layer was washed with saturated aqueous sodium chloride solution
- dry with materialdried over magnesium sulfate
- filtrationfiltered
- concentrationconcentrated in vacuo
- customThe residue was purified via silica gel chromatography (Gradient: 0% to 5% methanol in dichloromethane)
Sources & evidence
- ORD record
- ord-b938a0578f5f4ed788a8a441bddeb09a
- Source dataset
- uspto-grants-2012_10
- Patent number
- US08278457B2
Reaction notes
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