Lithium borohydride → HCID 25138433, compound

HRID 1044441Notes

Reaction equation

HRID 1044441 reaction equation
[CH2:1]([O:8][C:9]1[CH:33]=[C:32]([O:34][Si:35]([C:38]([CH3:41])([CH3:40])[CH3:39])([CH3:37])[CH3:36])[CH:31]=[CH:30][C:10]=1[C:11]1[C:20](=O)[C:19]2[C:14](=[CH:15][C:16]([O:22][CH2:23][C:24]3[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=3)=[CH:17][CH:18]=2)[O:13][CH:12]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[BH4-].[Li+]>C1COCC1>[CH2:1]([O:8][C:9]1[CH:33]=[C:32]([O:34][Si:35]([C:38]([CH3:41])([CH3:40])[CH3:39])([CH3:36])[CH3:37])[CH:31]=[CH:30][C:10]=1[C:11]1[CH2:12][O:13][C:14]2[C:19]([CH:20]=1)=[CH:18][CH:17]=[C:16]([O:22][CH2:23][C:24]1[CH:25]=[CH:26][CH:27]=[CH:28][CH:29]=1)[CH:15]=2)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

4

Reactant 2

HCID 4148881Lithium borohydrideHCID 53248200HCID 53248200, compound

Product 1

HCID 25138433HCID 25138433, compoundYield 45%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
60 °C

Procedure

To an ice cooled solution of 2′,7-dibenzyloxy-4′-(t-butyldimethylsilyloxy)-isoflavone (0.564 g, 1 mmol) in 10 mL of THF was added 1.6 M lithium borohydride solution in THF (3 mmol) dropwise. The reaction mixture was allowed to come to RT gradually and then stirred for ca. 2 hrs. After disappearance of the starting material (TLC) the reaction was quenched with 1N HCl (pH 4). The reaction was further stirred at room temperature followed by refluxing at 60° C. for ca. 2 hours. The reaction mixture was extracted with DCM:water (2×15 mL:15 mL). The organic layers were combined and washed with 1N NaHCO3 (2×15 mL), dried over sodium sulfate and evaporated at 20° C. to obtain an oily residue. The residue was chromatographed over silica using DCM:hexanes (1:1). The organic fractions were evaporated to provide 0.247 g (45%) of white solid: mp 105-107° C.; TLC Rf0.75 in DCM:hexanes (2:1); 1H NMR (400 MHz, DMSO-d6) δ 7.46-7.32 (m, 10H, 2×CH5), 7.22-7.20 (d, 1H, J=8.4 Hz, Ar—H5), 7.03-7.01 (d, 1H, J=8.4 Hz), 6.63 (s, 1H, CH═), 6.58-6.55 (m, 2H, Ar—H3′/H5′), 6.49-6.46 (m, 2H, Ar—H6/8), 5.11 (s, 2H, Ph-CH2), 5.07 (s, 2H, Ph-CH2), 4.89 (s, 2H, OCH2), 0.93 {s, 9H, Si(CH3)3}, 0.17 {s, 6H, Si(CH3)2}; 13C NMR (100 MHz, DMSO-d6) δ 199.6, 159.7, 157.5, 156.8, 154.7, 137.7, 137.5, 129.7, 129.2, 129.1, 128.6, 128.5, 128.4, 128.3, 128.1, 121.5, 121.4, 117.5, 112.8, 108.9, 105.9, 102.8, 70.5, 69.9, 68.3, 26.3, 18.7; analysis calcd. for C35H38O4Si.0.25H2O: C, 75.71; H, 6.99. found: C, 76.0; H, 6.70.

Workup

  1. customto come to RT
  2. customAfter disappearance of the starting material (TLC) the reaction was quenched with 1N HCl (pH 4)
  3. stirringThe reaction was further stirred at room temperature
  4. extractionThe reaction mixture was extracted with DCM
  5. washwashed with 1N NaHCO3 (2×15 mL)
  6. dry with materialdried over sodium sulfate
  7. customevaporated at 20° C.
  8. customto obtain an oily residue
  9. customThe residue was chromatographed over silica
  10. customThe organic fractions were evaporated

Sources & evidence

ORD record
ord-cb5145e806ef4031811c6bcddb7938ff
Source dataset
uspto-grants-2013_10
Patent number
US08563599B2

Reaction notes

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