Hydrochloric Acid → 3,4-Dichloro-5-methyl-1H-pyrrole-2-carboxylic acid

HRID 2233806Notes

Reaction equation

HRID 2233806 reaction equation
[Cl:1][C:2]1[C:6]([Cl:7])=[C:5]([CH3:8])[NH:4][C:3]=1[C:9]([O:11]CC)=[O:10].C(Cl)Cl.[Li+].[OH-].Cl>CO>[Cl:1][C:2]1[C:6]([Cl:7])=[C:5]([CH3:8])[NH:4][C:3]=1[C:9]([OH:11])=[O:10]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 3939Lithium HydroxideHCID 6344DichloromethaneHCID 68519325Ethyl 3,4-dichloro-5-methyl-1H-pyrrole-2-carboxylate2×

Product 1

HCID 251376823,4-Dichloro-5-methyl-1H-pyrrole-2-carboxylic acidYield 64%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

Ethyl 3,4-dichloro-5-methyl-1H-pyrrole-2-carboxylate (Intermediate 4, 7.765 g, 0.03496 mol) was dissolved in MeOH (80 ml) and DCM (10 ml) and slowly added to a 70° C. solution of 2 N LiOH (105 ml, 0.21 mol). After 2 h, the reaction mixture was cooled to room temperature and then in an ice bath, followed by acidification with 2 N HCl. The mixture was stirred at 0° C. for 1 h, and a purple solid was filtered, washed with water and lyophilized overnight to give 4.314 g (0.0222 mol, 64% yield) of the desired product.

Workup

  1. filtrationa purple solid was filtered
  2. washwashed with water
  3. waitlyophilized overnight

Sources & evidence

ORD record
ord-301786ab60e54854a5cdd1753f865dc3
Source dataset
uspto-grants-2010_05
Patent number
US07709503B2

Reaction notes

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