Diisobutylaluminumhydride → (3,5-Diethoxy-4-pyrrol-1-yl-phenyl)-methanol

HRID 2264488Notes

Reaction equation

HRID 2264488 reaction equation
C([O:3][C:4](=O)[C:5]1[CH:10]=[C:9]([O:11][CH2:12][CH3:13])[C:8]([N:14]2[CH:18]=[CH:17][CH:16]=[CH:15]2)=[C:7]([O:19][CH2:20][CH3:21])[CH:6]=1)C.[H-].C([Al+]CC(C)C)C(C)C>C1(C)C=CC=CC=1>[CH2:20]([O:19][C:7]1[CH:6]=[C:5]([CH2:4][OH:3])[CH:10]=[C:9]([O:11][CH2:12][CH3:13])[C:8]=1[N:14]1[CH:15]=[CH:16][CH:17]=[CH:18]1)[CH3:21]

Participants

4

Reactant 2

HCID 21225700DiisobutylaluminumhydrideHCID 669121583,5-Diethoxy-4-pyrrol-1-yl-benzoic acid ethyl ester

Product 1

HCID 66912179(3,5-Diethoxy-4-pyrrol-1-yl-phenyl)-methanolYield 100%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

To a solution of 3,5-diethoxy-4-pyrrol-1-yl-benzoic acid ethyl ester (1.51 g, 4.98 mmol, 1.0 equiv) in toluene (5 mL) was added slowly over a time period of 15 min under slight cooling to 20° C. a solution of diisobutylaluminium hydride (8.9 mL, 12.45 mmol, 2.5 equiv; 20% solution in toluene). After 1 h the excess hydride was quenched by cautious addition of water (10 mL) and a 28% solution of NaOH (2 mL). The mixture was stirred for 30 min and the organic phase filtered over Hyflo Super Cel. The aqueous layer was extracted with toluene (2×50 mL), the combined organic phases washed with a sat. solution of sodium chloride (2×50 mL) and concentrated by evaporation under reduced pressure to afford 1.30 g (100%) of (3,5-diethoxy-4-pyrrol-1-yl-phenyl)-methanol. The crude alcohol (1.30 g, 4.98 mmol, 1.0 equiv) was dissolved in toluene (20 mL) and activated MnO2 (7.79 g, 89.5 mmol, 18.0 equiv) was added. The reaction mixture was heated to reflux for 7 h, after which time the reaction was filtered through Hyflo Super Cel and concentrated yielding 1.15 g (89% yield) of the title compound. 1H NMR (300 MHz, DMSO): δ 1.17 (t, J=7.0 Hz, 6H), 4.02 (q, J=7.0 Hz, 4H), 6.08-6.09 (m, 2H), 6.75-6.76 (m, 2H), 7.25 (s, 2H), 9.89 (s, 1H). MS (ISP): 260.1 [M+H]+.

Workup

  1. customAfter 1 h the excess hydride was quenched by cautious addition of water (10 mL)
  2. filtrationthe organic phase filtered over Hyflo Super Cel
  3. extractionThe aqueous layer was extracted with toluene (2×50 mL)
  4. washthe combined organic phases washed with a sat. solution of sodium chloride (2×50 mL)
  5. concentrationconcentrated by evaporation under reduced pressure

Sources & evidence

ORD record
ord-22a6ead9640b4d07820a76572830c786
Source dataset
uspto-grants-2010_12
Patent number
US07855194B2

Reaction notes

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