Cesium carbonate → methyl 1-[3-(benzyloxy)propyl]-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrrole-2-carboxylate

HRID 2279825Notes

Reaction equation

[CH3:1][C:2]1([CH3:18])[C:6]([CH3:8])([CH3:7])[O:5][B:4]([C:9]2[CH:10]=[C:11]([C:14]([O:16][CH3:17])=[O:15])[NH:12][CH:13]=2)[O:3]1.Br[CH2:20][CH2:21][CH2:22][O:23][CH2:24][C:25]1[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=1.C(=O)([O-])[O-].[Cs+].[Cs+]>CN(C=O)C.O>[CH2:24]([O:23][CH2:22][CH2:21][CH2:20][N:12]1[CH:13]=[C:9]([B:4]2[O:3][C:2]([CH3:18])([CH3:1])[C:6]([CH3:7])([CH3:8])[O:5]2)[CH:10]=[C:11]1[C:14]([O:16][CH3:17])=[O:15])[C:25]1[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=1

Participants

Conditions

Temperature: 70 °C

Procedure

A mixture of methyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrrole-2-carboxylate (Compound 38F, 600 mg, 2.39 mmol) and 1-bromo-3-benzyloxypropane (575 mg, 2.51 mmol) in DMF (2.19 mL) was charged with cesium carbonate (778 mg, 2.39 mmol). The reaction mixture was allowed to stir at 70° C. for 16 hrs. The reaction mixture was diluted with water and then extracted with EtOAc (2×). The organic layer was washed with water (2×), brine (1×), dried over Na2SO4, filtered, concentrated in vacuo and purified using a Teledyne ISCO Combiflash® Rf system [0→4% Ethanol in DCM] to afford 442 mg of the title compound (46%). 1H NMR (400 MHz, CD3OD) δ 7.26-7.37 (m, 5H), 7.25 (d, J=1.8 Hz, 1H), 7.17 (d, J=1.8 Hz, 1H), 4.45 (s, 2H), 4.42 (t, J=6.8 Hz, 2H), 3.78 (s, 3H), 3.38 (t, J=5.9 Hz, 2H), 2.01 (t, J=6.2 Hz, 2H), 1.31 (s, 12H). MS (ESI): m/z 440.59 [M+H]+. UPLC: tR=1.60 min (UPLC-TOF: polar—2 min).

Workup

extractionextracted with EtOAc (2×)
washThe organic layer was washed with water (2×), brine (1×)
dry with materialdried over Na2SO4
filtrationfiltered
concentrationconcentrated in vacuo
custompurified

Sources & evidence

ORD record: ord-0b597521263d443cb6c96f7011bbd266
Source dataset: uspto-grants-2015_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09133224B2

Reaction notes

Loading…