Cesium carbonate → methyl 2-[(2'-oxospiro[furo[2,3-f][1,3]benzodioxole-7,3'-indol]-1'(2'H)-yl)methyl]-1,3-oxazole-4-carboxylate

HRID 1407474Notes

Reaction equation

HRID 1407474 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[C:3]2([C:13]3=[CH:14][C:15]4[O:19][CH2:18][O:17][C:16]=4[CH:20]=[C:12]3[O:11][CH2:10]2)[C:2]1=[O:21].Cl[CH2:23][C:24]1[O:25][CH:26]=[C:27]([C:29]([O:31][CH3:32])=[O:30])[N:28]=1.C(=O)([O-])[O-].[Cs+].[Cs+]>O1CCCC1>[O:21]=[C:2]1[C:3]2([C:13]3=[CH:14][C:15]4[O:19][CH2:18][O:17][C:16]=4[CH:20]=[C:12]3[O:11][CH2:10]2)[C:4]2[C:9](=[CH:8][CH:7]=[CH:6][CH:5]=2)[N:1]1[CH2:23][C:24]1[O:25][CH:26]=[C:27]([C:29]([O:31][CH3:32])=[O:30])[N:28]=1

Participants

5

Reactant 3

HCID 10796Cesium carbonateHCID 2763199Methyl 2-(chloromethyl)oxazole-4-carboxylateHCID 53375495spiro[furo[2,3-f][1,3]benzodioxole-7,3'-indol]-2'(1'H)-one

Product 1

HCID 68599804methyl 2-[(2'-oxospiro[furo[2,3-f][1,3]benzodioxole-7,3'-indol]-1'(2'H)-yl)methyl]-1,3-oxazole-4-carboxylateYield 92%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A suspended mixture of spiro[furo[2,3-f][1,3]benzodioxole-7,3′-indol]-2′(1′H)-one (1.60 g, 5.70 mmol), methyl 2-(chloromethyl)oxazole-4-carboxylate (1.00 g, 5.70 mmol) and cesium carbonate (3.71 g, 11.4 mmol) in tetrahydrofuran (10 mL) was refluxed for 16 h. The reaction mixture was cold down to ambient temperature and concentrated in vacuo. The residue was treated with water (20 mL) and extracted with ethyl acetate (3×20 mL). The combined organic solution was dried over sodium sulfate and filtered. The filtrate was concentrated in vacuo to dryness. The residue was purified by column chromatography with a 20% to 30% gradient of ethyl acetate in hexanes to afford methyl 2-[(2′-oxospiro[furo[2,3-f][1,3]benzodioxole-7,3′-indol]-1′(2′H)-yl)methyl]-1,3-oxazole-4-carboxylate (2.19 g, 92%) as a colorless solid: mp 183-185° C.; 1H NMR (300 MHz, DMSO-d6) δ 8.86 (s, 1H), 7.28 (t, J=7.2 Hz, 1H), 7.16 (d, J=7.0 Hz, 1H), 7.09 (d, J=7.8 Hz, 1H), 7.03 (t, J=7.5 Hz, 1H), 6.66 (s, 1H), 6.41 (s, 1H), 5.90 (d, J=2.1 Hz, 2H), 5.23-5.17 (m, 2H), 4.74 (ABq, 2H), 3.74 (s, 3H); 13C NMR (75 MHz, DMSO-d6) δ177.2, 161.3, 160.2, 155.6, 148.8, 146.9, 142.3, 142.0, 132.8, 132.4, 129.4, 124.1, 123.9, 120.4, 109.7, 103.9, 101.9, 93.7, 80.0, 57.9, 52.3, 37.4; MS (ES+) m/z 421.2 (M+1).

Workup

  1. temperaturewas refluxed for 16 h
  2. customwas cold down to ambient temperature
  3. concentrationconcentrated in vacuo
  4. additionThe residue was treated with water (20 mL)
  5. extractionextracted with ethyl acetate (3×20 mL)
  6. dry with materialThe combined organic solution was dried over sodium sulfate
  7. filtrationfiltered
  8. concentrationThe filtrate was concentrated in vacuo to dryness
  9. customThe residue was purified by column chromatography with a 20% to 30% gradient of ethyl acetate in hexanes

Sources & evidence

ORD record
ord-3c0d3b313d114cb58b2360dda915d918
Source dataset
uspto-grants-2014_12
Patent number
US08916580B2

Reaction notes

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