Triethylsilane → 6,7-dihydro-5H-spiro[furo[3,2-g]chromene-3,3'-indol]-2'(1'H)-one

HRID 2385206Notes

Reaction equation

HRID 2385206 reaction equation
C1(C(C2C=CC=CC=2)[N:8]2[C:16]3[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=3)[C:10]3([C:20]4[CH:21]=[C:22]5[C:27](=[CH:28][C:19]=4[O:18][CH2:17]3)[O:26][CH2:25][CH2:24][CH2:23]5)[C:9]2=[O:29])C=CC=CC=1.C([SiH](CC)CC)C>FC(F)(F)C(O)=O.O>[NH:8]1[C:16]2[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=2)[C:10]2([C:20]3[CH:21]=[C:22]4[C:27](=[CH:28][C:19]=3[O:18][CH2:17]2)[O:26][CH2:25][CH2:24][CH2:23]4)[C:9]1=[O:29]

Participants

5

Reactant 2

HCID 12052TriethylsilaneHCID 593523511'-(diphenylmethyl)-6,7-dihydro-5H-spiro[furo[3,2-g]chromene-3,3'-indol]-2'(1'H)-one

Product 1

HCID 673578866,7-dihydro-5H-spiro[furo[3,2-g]chromene-3,3'-indol]-2'(1'H)-oneYield 64.6%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6422Trifluoroacetic acidSolvent

Procedure

A solution of 1′-(diphenylmethyl)-6,7-dihydro-5H-spiro[furo[3,2-g]chromene-3,3′-indol]-2′(1′H)-one (0.61 g, 1.32 mmol) and triethylsilane (0.67 mL, 4.2 mmol) in trifluoroacetic acid (4.5 mL) was stirred at reflux under nitrogen for 2.5 h. Once cooled, the reaction was diluted with water (40 mL) and extracted with ethyl acetate (3×25 mL). The combined organic solution was washed with brine (50 mL), dried (sodium sulfate), filtered and concentrated under reduced pressure. The residue was dissolved into 10% diethyl ether in dichloromethane (5 mL) and, after standing at ambient temperature, yielded a colorless precipitate. This material was collected by filtration and washed with hexanes. Drying in air provided 6,7-dihydro-5H-spiro[furo[3,2-g]chromene-3,3′-indol]-2′(1′H)-one (0.25 g, 63%) as a colorless solid. An additional portion (0.14 g, 37%) of product was also recovered by concentrating the filtrate and triturating the residual solid with hexanes: mp 216-220° C. (hexanes); 1H NMR (300 MHz, DMSO-d6) δ10.58 (s, 1H), 7.23 (ddd, J=7.8, 7.5, 0.9 Hz, 1H), 7.08 (d, J=7.2 Hz, 1H), 6.98-6.91 (m, 2H), 6.36 (s, 1H), 6.31 (s, 1H), 4.74 (d, J=9.0 Hz, 1H), 4.61 (d, J=9.0 Hz, 1H), 4.05 (dd, J=5.1, 4.8 Hz, 2H), 2.61-2.45 (m, 2H), 1.84-1.77 (m, 2H); 13C NMR (75 MHz, DMSO-d6) δ178.6, 159.5, 155.4, 141.8, 132.9, 128.6, 123.8, 123.6, 122.3, 121.4, 114.8, 109.7, 97.9, 79.5, 66.0, 57.3, 23.9, 21.7; MS (ES+) m/z 294.1 (M+1).

Workup

  1. temperatureat reflux under nitrogen for 2.5 h
  2. temperatureOnce cooled
  3. extractionextracted with ethyl acetate (3×25 mL)
  4. washThe combined organic solution was washed with brine (50 mL)
  5. dry with materialdried (sodium sulfate)
  6. filtrationfiltered
  7. concentrationconcentrated under reduced pressure
  8. dissolutionThe residue was dissolved into 10% diethyl ether in dichloromethane (5 mL)
  9. customafter standing at ambient temperature
  10. customyielded a colorless precipitate
  11. filtrationThis material was collected by filtration
  12. washwashed with hexanes
  13. customDrying in air

Sources & evidence

ORD record
ord-137fd54b2ea04e989dfed1ca27fed12f
Source dataset
uspto-grants-2012_09
Patent number
US08263606B2

Reaction notes

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