Hydrochloric Acid → HCID 21071898, compound

HRID 1372422Notes

Reaction equation

HRID 1372422 reaction equation
P(Cl)(Cl)(Cl)=O.[CH3:6][C:7]1[NH:8][CH:9]=[C:10]([CH3:21])[C:11]=1[C:12]1[CH:20]=[CH:19][C:15](C(O)=O)=[CH:14][CH:13]=1.[OH-].[K+].Cl.[C:25]([O:28]CC)(=[O:27])C.CCCCCC.[C:37](O)(=[O:39])C>ClCCl.O.CN(C)C=O>[CH:37]([C:9]1[NH:8][C:7]([CH3:6])=[C:11]([C:12]2[CH:13]=[C:14]([CH:15]=[CH:19][CH:20]=2)[C:25]([OH:28])=[O:27])[C:10]=1[CH3:21])=[O:39]

Participants

9

Reactant 5

HCID 313Hydrochloric AcidHCID 14797Potassium HydroxideHCID 24813Phosphorus oxychlorideHCID 21071901HCID 21071901, compoundHCID 21901998Ethyl acetate hexane acetic acid

Product 1

HCID 21071898HCID 21071898, compoundYield 50%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 6228DimethylformamideSolventHCID 6344DichloromethaneSolvent2×

Conditions

Temperature
5 °C

Procedure

Dimethylformamide (7.5 mL) and 55 mL of dichloromethane were cooled to 3° C. and 7.2 mL of phosphorus oxychloride were added with stirring. 4-(2,4-Dimethyl-1H-pyrrol-3-yl)-benzoic acid (10.9 g) was slowly added. The mixture was refluxed for 30 minutes. Thin layer chromatography (ethyl acetate:hexane:acetic acid 4:6:0.5) showed no starting material at Rf 0.6 and a new spot at the origin. The mixture was cooled to 5° C. and 55 mL of ice water were added. Potassium hydroxide (9 N, 50 mL total) was slowly added with cooling. The final pH was 12–13. The maximum temperature reached was 48° C. Water (100 mL) was added along with 15 mL of dichloromethane to replace that which had boiled off. The aqueous phase was isolated at a temperature of about 35° C. The aqueous phase was adjusted to pH 3 by slow addition of about 21 mL of 10 N hydrochloric acid with stirring and cooling in an ice bath. The solids were collected by vacuum filtration and washed 3 times with 15 mL of water each time to give 6.1 g (50% yield) of 3-(5-formyl-2,4-dimethyl-1H-pyrrol-3-yl)-benzoic acid as a reddish solid. 1H-NMR (dimethylsulfoxide-d6) δ 2.20, 2.24 (2×s, 2×3H, 2×CH3), 7.53, 7.78, 7.85 (multiplets, 4H, aromatic), 9.55 (s, 1H, CHO), 11.85 (br s, 2H, and COOH). MS m/z 244 [M+1].

Workup

  1. temperatureThe mixture was refluxed for 30 minutes
  2. temperaturewith cooling
  3. customreached was 48° C
  4. customThe aqueous phase was isolated at a temperature of about 35° C
  5. stirringwith stirring
  6. temperaturecooling in an ice bath
  7. filtrationThe solids were collected by vacuum filtration
  8. washwashed 3 times with 15 mL of water each time

Sources & evidence

ORD record
ord-9f828cbba2a04018b8d23d7cd5902d3a
Source dataset
uspto-grants-2007_01
Patent number
US07157577B2

Reaction notes

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