Sulfuric Acid → 2-(4-Tert-butyl-benzoylamino)-4-hydroxy-benzoic acid methyl ester

HRID 29662Notes

Reaction equation

HRID 29662 reaction equation
[CH3:1][O:2][C:3](=[O:24])[C:4]1[CH:9]=[CH:8][C:7](N)=[CH:6][C:5]=1[NH:11][C:12](=[O:23])[C:13]1[CH:18]=[CH:17][C:16]([C:19]([CH3:22])([CH3:21])[CH3:20])=[CH:15][CH:14]=1.N([O-])=[O:26].[Na+].OS(O)(=O)=O>FC(F)(F)C(O)=O.O>[CH3:1][O:2][C:3](=[O:24])[C:4]1[CH:9]=[CH:8][C:7]([OH:26])=[CH:6][C:5]=1[NH:11][C:12](=[O:23])[C:13]1[CH:18]=[CH:17][C:16]([C:19]([CH3:22])([CH3:21])[CH3:20])=[CH:15][CH:14]=1

Participants

6

Reactant 3

HCID 1118Sulfuric AcidHCID 23668193Sodium NitriteHCID 691966714-Amino-2-(4-tert-butyl-benzoylamino)-benzoic acid methyl ester

Product 1

HCID 691962732-(4-Tert-butyl-benzoylamino)-4-hydroxy-benzoic acid methyl esterYield 71%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6422Trifluoroacetic acidSolvent

Procedure

To a solution of 4-amino-2-(4-tert-butyl-benzoylamino)-benzoic acid methyl ester (0.711 g, 2.18 mmol) in trifluoroacetic acid cooled to 0° C. was added NaNO2 (0.182 g, 2.64 mmol, 1.21 eq) as a solution in water (4 mL) and the reaction was stirred for 5 minutes. It was then added dropwise to a 30% solution of H2SO4 (50 mL) at 65° C. and stirred for 15 minutes. It was extracted with ethyl acetate, dried over MgSO4 and concentrated in vacuo. The residue was purified by flash chromatography using ethyl acetate/hexanes (20/80) to afford 2-(4-tert-butyl-benzoylamino)-4-hydroxy-benzoic acid methyl ester (0.508, 71%) as a white solid. mp=146.0-148.4° C.; mass spectrum (−ES, M−H) m/z 326. 1H NMR (400 MHz, DMSO-d6); δ 11.95 (bs, 1H), 10.60 (bs, 1H), 8.26 (d, 1H), 7.88 (m, 3H), 7.62 (d, 2H), 6.58 (dd, 1H), 3.85 (s, 3H), 1.32 (s, 9H). Elemental analysis: Calcd. for C19H21NO4: C, 69.71; H, 6.47; N, 4.28, Found: C, 69.20; H, 6.54; N, 4.17.

Workup

  1. stirringstirred for 15 minutes
  2. extractionIt was extracted with ethyl acetate
  3. dry with materialdried over MgSO4
  4. concentrationconcentrated in vacuo
  5. customThe residue was purified by flash chromatography

Sources & evidence

ORD record
ord-2f4dd14e73bb4e4e88456187c30bafd3
Source dataset
uspto-grants-2008_09
Patent number
US07420083B2

Reaction notes

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