Cesium carbonate → 4-(Cyclopropanecarbonyl-amino)-3-methyl-benzofuran-2-carboxylic acid ethyl ester

HRID 29297

Reaction equation

HRID 29297 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[O:7][C:8]2[CH:15]=[CH:14][CH:13]=[C:12](OS(C(F)(F)F)(=O)=O)[C:9]=2[C:10]=1[CH3:11])=[O:5])[CH3:2].[CH:24]1([C:27]([NH2:29])=[O:28])[CH2:26][CH2:25]1.C1(P(C2C=CC=CC=2)C2C3OC4C(=CC=CC=4P(C4C=CC=CC=4)C4C=CC=CC=4)C(C)(C)C=3C=CC=2)C=CC=CC=1.C(=O)([O-])[O-].[Cs+].[Cs+]>O1CCOCC1.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.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].[Pd]>[CH2:1]([O:3][C:4]([C:6]1[O:7][C:8]2[CH:15]=[CH:14][CH:13]=[C:12]([NH:29][C:27]([CH:24]3[CH2:26][CH2:25]3)=[O:28])[C:9]=2[C:10]=1[CH3:11])=[O:5])[CH3:2]

Participants

7

Procedure

To 3-methyl-4-trifluoromethanesulfonyloxy-benzofuran-2-carboxylic acid ethyl ester (300 mg, 0.85 mmol, 1 eq, prepared according to Example 20, Step 1) in 8 mL of dioxane under nitrogen were added cyclopropyl carboxamide (87 mg, 1.02 mmol, 1.2 eq), Pd2 (dba)3 (16 mg, 0.017 mmol, 0.02 eq), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (30 mg, 0.051 mmol, 0.06 eq), and cesium carbonate (390 mg, 1.19 mmol, 1.4 eq). The reaction mixture was heated at reflux for 72 h. After work up and column chromatography (dichloromethane/hexanes), 4-(cyclopropanecarbonyl-amino)-3-methyl-benzofuran-2-carboxylic acid ethyl ester was obtained in 98% yield (238 mg). 1H NMR (400 MHz, DMSO-d6) δ ppm 0.8 (m, 4 H) 1.3 (t, J=7.1 Hz, 3 H) 1.8 (s, 1 H) 2.6 (s, 3 H) 4.4 (q, J=7.2 Hz, 2 H) 7.2 (d, J=7.1 Hz, 1 H) 7.5 (m, 1 H) 7.5 (m, 1 H) 10.1 (s, 1 H).

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureat reflux for 72 h

Sources & evidence

ORD record
ord-6cb6a804429c49f08029e7b531d8aa19
Source dataset
uspto-grants-2008_09
Patent number
US07420001B2

Linked notes

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