Citric Acid → 5-naphthalen-1-yl-1H-pyrrole-2-carboxylic acid chloride

HRID 985608Notes

Reaction equation

HRID 985608 reaction equation
C[O:2][C:3]([C:5]1[NH:6][C:7]([C:10]2[C:19]3[C:14](=[CH:15][CH:16]=[CH:17][CH:18]=3)[CH:13]=[CH:12][CH:11]=2)=[CH:8][CH:9]=1)=O.O.[OH-].[Li+].C(O)(=O)CC(CC(O)=O)(C(O)=O)O.C(Cl)(=O)C([Cl:39])=O>O1CCOCC1.O.CN(C=O)C>[C:10]1([C:7]2[NH:6][C:5]([C:3]([Cl:39])=[O:2])=[CH:9][CH:8]=2)[C:19]2[C:14](=[CH:15][CH:16]=[CH:17][CH:18]=2)[CH:13]=[CH:12][CH:11]=1

Participants

7

Reactant 4

HCID 311Citric AcidHCID 65578Oxalyl chlorideHCID 168937Lithium hydroxide, monohydrateHCID 697453065-naphthalen-1-yl-1H-pyrrole-2-carboxylic acid methyl ester

Product 1

HCID 879770875-naphthalen-1-yl-1H-pyrrole-2-carboxylic acid chloride

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideCatalystHCID 218864351,4-Dioxane--water (1/1)Solvent

Procedure

5-Naphthalen-1-yl-1H-pyrrole-2-carboxylic acid methyl ester was diluted with 1:1 dioxane-water (30 ml), and treated with lithium hydroxide hydrate (24.4 mmol, 1.02 g), then heated to reflux for 15 min. The solution was acidified with 20% aqueous citric acid (30 ml), then extracted with ethyl acetate (75 ml). The organics were washed with brine (2×20 ml), then concentrated under reduced pressure. The residue was diluted with CH2Cl2, (30 ml), and treated with oxalyl chloride (24.0 mmol, 2.10 ml), and DMF (one drop), then heated to reflux for 30 min. The solution was concentrated under reduced pressure to provide 1.95 g of 5-naphthalen-1-yl-1H-pyrrole-2-carboxylic acid chloride.

Workup

  1. temperatureheated
  2. temperatureto reflux for 15 min
  3. extractionextracted with ethyl acetate (75 ml)
  4. washThe organics were washed with brine (2×20 ml)
  5. concentrationconcentrated under reduced pressure
  6. additionThe residue was diluted with CH2Cl2, (30 ml)
  7. temperatureheated
  8. temperatureto reflux for 30 min
  9. concentrationThe solution was concentrated under reduced pressure

Sources & evidence

ORD record
ord-478997a75ce0418794edde9dbb1412d2
Source dataset
uspto-grants-2005_03
Patent number
US06872745B2

Reaction notes

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