Sodium Hydroxide → 4-(4-bromo-1-methyl-1H-pyrazol-5-yl)-5-methyl-2-thiophenecarboxylic acid

HRID 1961205Notes

Reaction equation

HRID 1961205 reaction equation
C1C(=O)N([Br:8])C(=O)C1.[CH3:9][C:10]1[S:14][C:13]([C:15]([O:17]C)=[O:16])=[CH:12][C:11]=1[C:19]1[N:23]([CH3:24])[N:22]=[CH:21][CH:20]=1.[OH-].[Na+]>O1CCCC1>[Br:8][C:20]1[CH:21]=[N:22][N:23]([CH3:24])[C:19]=1[C:11]1[CH:12]=[C:13]([C:15]([OH:17])=[O:16])[S:14][C:10]=1[CH3:9]

Participants

5

Reactant 3

HCID 14798Sodium HydroxideHCID 67184N-bromobutanimideHCID 57826485methyl 5-methyl-4-(1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate

Product 1

HCID 578265224-(4-bromo-1-methyl-1H-pyrazol-5-yl)-5-methyl-2-thiophenecarboxylic acidYield 105.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
70 °C

Procedure

NBS (1.84 g, 10.33 mmol) was added in portions to a 150 mL sealed tube reactor containing methyl 5-methyl-4-(1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (2 g, 8.46 mmol) [prepared according to the procedure of Preparation 10] in Tetrahydrofuran (THF) (40 ml) at room temperature. The mixture was heated to 70° C. for 1 h. 6N NaOH (28 ml, 168 mmol) was then added and the mixture stirred at 70° C. for 2 h. The mixture was partitioned between CHCl3 and H2O and the aqueous layer was made acidic with 6N HCl. The aqueous phase was washed several times with CHCl3 and the organic fractions were combined, dried over Na2SO4 and concentrated affording the title compound (2.68 g, 8.9 mmol, quant.): LC-MS (ES) m/z=302 (M+H)+.

Workup

  1. customsealed tube reactor
  2. customprepared
  3. customThe mixture was partitioned between CHCl3 and H2O
  4. washThe aqueous phase was washed several times with CHCl3
  5. dry with materialdried over Na2SO4
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-cd1b08df9fb044a5bc85a88dbc762d6a
Source dataset
uspto-grants-2013_04
Patent number
US08410158B2

Reaction notes

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