Water → 2-Amino-5-(4-methoxy-phenyl)-thiophene-3-carboxylic acid

HRID 30340Notes

Reaction equation

HRID 30340 reaction equation
C[O:2][C:3]([C:5]1[CH:9]=[C:8]([C:10]2[CH:15]=[CH:14][C:13]([O:16][CH3:17])=[CH:12][CH:11]=2)[S:7][C:6]=1[NH2:18])=[O:4].[OH-].[Na+].O>CO>[NH2:18][C:6]1[S:7][C:8]([C:10]2[CH:15]=[CH:14][C:13]([O:16][CH3:17])=[CH:12][CH:11]=2)=[CH:9][C:5]=1[C:3]([OH:4])=[O:2]

Participants

5

Reactant 3

HCID 962WaterHCID 14798Sodium HydroxideHCID 689635672-Amino-5-(4-methoxy-phenyl)-thiophene-3-carboxylic acid methyl ester

Product 1

HCID 689579752-Amino-5-(4-methoxy-phenyl)-thiophene-3-carboxylic acidYield 91%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a stirred solution of 2-amino-5-(4-methoxy-phenyl)-thiophene-3-carboxylic acid methyl ester (6.6 g, 26.6 mmol) in MeOH (200 mL) was added 6N NaOH (100 mL) and water (50 mL). The reaction was heated to reflux for 2 h or until starting material was gone by TLC or LCMS. The solution was concentrated under vacuum to about half of the original volume. The pH of the resultant cloudy mixture was adjusted to 3-5 by the careful addition of 6N HCl (˜150 mL) while stirring. The gummy red precipitate was filtered and dried. Purification was achieved by triturating in boiling hexanes. The product (6.0 g, 91%) was isolated in pure form by filtration after cooling to room temperature and drying in a vacuum oven overnight. 1H NMR (d6-DMSO δ 7.37, d, 2H, δ 7.11, s, 1H; δ 7.10, br s, 2H; δ 6.94, d, 2H), LC/MS (APCI, ES, M+H=250).

Workup

  1. temperatureThe reaction was heated
  2. temperatureto reflux for 2 h
  3. concentrationThe solution was concentrated under vacuum to about half of the original volume
  4. additionThe pH of the resultant cloudy mixture was adjusted to 3-5 by the careful addition of 6N HCl (˜150 mL)
  5. filtrationThe gummy red precipitate was filtered
  6. customdried
  7. customPurification
  8. customby triturating

Sources & evidence

ORD record
ord-53951d626cc64e1db4cdb53e1bcc500e
Source dataset
uspto-grants-2008_09
Patent number
US07423061B2

Reaction notes

Loading…