Cesium carbonate → HCID 68842939, compound

HRID 1784871Notes

Reaction equation

Br[C:2]1[CH:3]=[C:4]([C:9]2[O:10][C:11]3[CH:17]=[CH:16][CH:15]=[CH:14][C:12]=3[N:13]=2)[CH:5]=[C:6]([Br:8])[CH:7]=1.[CH2:18]([O:25][C:26](=[O:28])[NH2:27])[C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1.C(=O)([O-])[O-].[Cs+].[Cs+].CC1(C)C2C(=C(P(C3C=CC=CC=3)C3C=CC=CC=3)C=CC=2)OC2C(P(C3C=CC=CC=3)C3C=CC=CC=3)=CC=CC1=2>C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd]>[CH2:18]([O:25][C:26](=[O:28])[NH:27][C:2]1[CH:7]=[C:6]([Br:8])[CH:5]=[C:4]([C:9]2[O:10][C:11]3[CH:17]=[CH:16][CH:15]=[CH:14][C:12]=3[N:13]=2)[CH:3]=1)[C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1

Participants

Conditions

Temperature: 60 °C

Procedure

2-(3,5-Dibromo-phenyl)-benzoxazole (0.4 g, 1.10 mmol), carbamic acid benzyl ester (0.17 g, 1.10 mmol), cesium carbonate (0.74 g, 2.30 mmol), Xantphos (46.0 mg, 0.08 mmol) and Pd(dba)2 (62.0 mg, 0.74 mmol) were placed into a dry two-neck flask, which was then flushed with nitrogen. 1,4-Dioxane (5.0 mL) was added into the flask, and the reaction mixture was degassed with argon at room temperature for 40 min. The mixture was heated to 60° C. and stirred for 18 h. The solvent was removed under reduced pressure and the residue was purified by silica gel chromatography eluting with 5:1/hexanes:ethyl acetate to give (3-benzoxazol-2-yl-5-bromo-phenyl)-carbamic acid benzyl ester (0.22 g, 46%) as a yellow solid.

Workup

customwhich was then flushed with nitrogen
addition1,4-Dioxane (5.0 mL) was added into the flask
customthe reaction mixture was degassed with argon at room temperature for 40 min
customThe solvent was removed under reduced pressure
customthe residue was purified by silica gel chromatography
washeluting with 5:1/hexanes

Sources & evidence

ORD record: ord-c921fa3934a246efafb7e0885251b9e0
Source dataset: uspto-grants-2009_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07504401B2

Reaction notes

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