Hydrochloric Acid → (4-Nitro-2-phenylbenzoyl)methionine 2-trimethylsilylethyl ester

HRID 2121222Notes

Reaction equation

HRID 2121222 reaction equation
[CH3:1][O:2][C:3](=[O:27])[C@H:4]([CH2:23][CH2:24][S:25][CH3:26])[NH:5][C:6](=[O:22])[C:7]1[CH:12]=[CH:11][C:10]([N+:13]([O-:15])=[O:14])=[CH:9][C:8]=1[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1.[OH-].[Li+].Cl.[CH3:31][Si:32]([CH3:37])([CH3:36])[CH2:33]CO.C(N=C=NC(C)C)(C)C>CO.CN(C)C1C=CN=CC=1.C1COCC1>[CH3:31][Si:32]([CH3:37])([CH3:36])[CH2:33][CH2:1][O:2][C:3](=[O:27])[C@H:4]([CH2:23][CH2:24][S:25][CH3:26])[NH:5][C:6](=[O:22])[C:7]1[CH:12]=[CH:11][C:10]([N+:13]([O-:15])=[O:14])=[CH:9][C:8]=1[C:16]1[CH:17]=[CH:18][CH:19]=[CH:20][CH:21]=1

Participants

9

Reactant 5

HCID 313Hydrochloric Acid2×HCID 3939Lithium HydroxideHCID 12734DiisopropylcarbodiimideHCID 180132-(Trimethylsilyl)ethanolHCID 18666764(4-Nitro-2-phenylbenzoyl)methionine methyl ester

Product 1

HCID 69844218(4-Nitro-2-phenylbenzoyl)methionine 2-trimethylsilylethyl esterYield 87%

Reagents, catalysts & solvents 3

HCID 142844-(Dimethylamino)pyridineCatalystHCID 887MethanolSolventHCID 8028TetrahydrofuranSolvent

Procedure

A mixture of (4-nitro-2-phenylbenzoyl)methionine methyl ester (7.69 g, 30 mmol), prepared as in Example 192A and aqueous saturated lithium hydroxide (20 mL) in methanol (50 mL) was refluxed for 6 hours. The reaction mixture was carefully acidified with concentrated hydrochloric acid (10 mL), and extracted with ethyl acetate (4×). The combine extracts were washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. The residue was dissolved in dichloromethane (50 mL) and THF (10 mL) and 2-trimethylsilylethanol (3.72 g, 31.5 mmol), 1,3-diisopropylcarbodiimide (5.17 mL, 33 mmol) and 4-dimethylaminopyridine (30 mg) were added sequentially. After 4 hours, aqueous hydrochloric acid (0.1 N, 0.5 mL) was added and the reaction mixture was stirred for another 2 hours. The reaction mixture was then filtered through silica gel (40 g), and the filtrate was concentrated in vacuo. The residue was purified by column chromatography (5% ethyl ether-hexane) to give the title compound (8.90 g, 87%).

Workup

  1. temperaturewas refluxed for 6 hours
  2. extractionextracted with ethyl acetate (4×)
  3. washThe combine extracts were washed with brine
  4. dry with materialdried over anhydrous magnesium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. dissolutionThe residue was dissolved in dichloromethane (50 mL)
  8. filtrationThe reaction mixture was then filtered through silica gel (40 g)
  9. concentrationthe filtrate was concentrated in vacuo
  10. customThe residue was purified by column chromatography (5% ethyl ether-hexane)

Sources & evidence

ORD record
ord-c9352c20a5d0439eb70d4779182299fe
Source dataset
uspto-grants-2004_02
Patent number
US06693123B2

Reaction notes

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