Sodium Hydroxide → 5-(Phenylmethyl)-1H-pyrrole-2-carboxylic acid

HRID 1434744Notes

Reaction equation

HRID 1434744 reaction equation
[OH-].[Na+].C([O:5][C:6]([C:8]1[NH:9][C:10]([CH2:13][C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)=[CH:11][CH:12]=1)=[O:7])C>CO>[CH2:13]([C:10]1[NH:9][C:8]([C:6]([OH:7])=[O:5])=[CH:12][CH:11]=1)[C:14]1[CH:15]=[CH:16][CH:17]=[CH:18][CH:19]=1

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 14449694HCID 14449694, compound

Product 1

HCID 184690125-(Phenylmethyl)-1H-pyrrole-2-carboxylic acid

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

Freshly prepared aq. NaOH (10 M in H2O, 4.78 mmol) was added to a stirring, room temperature solution of 31 (0.2190 g, 0.955 mmol) in MeOH (2.4 mL, 0.4 M) under N2. The reaction was heated to reflux until the reaction was judged complete by HPLC (40 min). The product was concentrated and then dissolved in 1.9 mL H2O. 10% aq. HCl was added dropwise until the pH=2. The white solid that precipitated from the reaction was filtered off and washed with cold H2O. The solid was dried under vacuum overnight to obtain 32 as a pale pink, impure solid (0.0845 g). 32 was further purified by adding CHCl3, stirring, and filtering off pure white 32 (0.0445 g). Note. The undesired impurity has a retention time of 9.643 min by HPLC. Also, the 13C NMR of 32 at room temperature showed doublets for the peaks corresponding to the pyrrole carbons, benzyl carbon, and acid carbon. When the NMR probe was heated to 28° C., all doubled peaks collapsed into single peaks as reported below. 1H (CD3OD, 400 MHz): δ 11.04 (1H, broad s), 7.27-7.13 (5H, m), 6.80 (1H, d, J=3.4 Hz), 5.87 (1H, d, J=3.4 Hz) 3.93 (2H, s) ppm. 13C (CD3OD, 100 MHz): δ 164.52, 140.71, 139.04, 129.56, 129.42, 127.27, 122.77, 117.59, 109.66, 34.65 ppm. DEPT (CD3OD, 100 MHz): CH2 carbons: 34.65; CH carbons: 129.56, 129.42, 127.27, 117.59, 109.66 ppm. HPLC: 8.698 min.

Workup

  1. temperatureThe reaction was heated
  2. temperatureto reflux until the reaction
  3. customwas judged complete by HPLC (40 min)
  4. concentrationThe product was concentrated
  5. dissolutiondissolved in 1.9 mL H2O
  6. addition10% aq. HCl was added dropwise until the pH=2
  7. customThe white solid that precipitated from the reaction
  8. filtrationwas filtered off
  9. washwashed with cold H2O
  10. customThe solid was dried under vacuum overnight

Sources & evidence

ORD record
ord-17225ed7b4b34df2bf37ffe2ca3b109d
Source dataset
uspto-grants-2009_11
Patent number
US07615572B2

Reaction notes

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