Phthalic Anhydride → 2-(2-Thienylcarbonyl)benzoic acid

HRID 628205Notes

Reaction equation

HRID 628205 reaction equation
[Cl-].[Al+3].[Cl-].[Cl-].[C:5]1(=[O:15])[O:10][C:8](=[O:9])[C:7]2=[CH:11][CH:12]=[CH:13][CH:14]=[C:6]12.[S:16]1[CH:20]=[CH:19][CH:18]=[CH:17]1>ClCCl>[S:16]1[CH:20]=[CH:19][CH:18]=[C:17]1[C:8]([C:7]1[CH:11]=[CH:12][CH:13]=[CH:14][C:6]=1[C:5]([OH:10])=[O:15])=[O:9]

Participants

5

Reactant 3

HCID 6811Phthalic AnhydrideHCID 8030ThiopheneHCID 6451240Aluminum(III) Chloride

Product 1

HCID 2826542-(2-Thienylcarbonyl)benzoic acid

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

Aluminum chloride (58.7 g, 440 mmol, 2.2 equiv.) and dichloromethane (150 mL) were added to a round bottom flask. A solution of phthalic anhydride (29.6 g, 200 mmol, 1.0 equiv.) in dichloromethane (150 mL) was then added, and the mixture was stirred at room temperature for 30 minutes. Thiophene (15.8 mL, 200 mL, 1.0 equiv.) was added over 1 hour, after which the reaction mixture was stirred for 3 hours at room temperature. The reaction mixture was cautiously quenched with hydrochloric acid (0.2 M, 1 L), extracted with dichloromethane, and extracted with aqueous NaOH (1 N, 3×200 mL). The aqueous layer was acidified with concentrated hydrochloric acid; the solids were collected by filtration, and stirred in refluxing methanol. The suspension was filtered, and water was added to the filtrate to crystallize 1 as a colorless solid (20.7 g, 45%). 1H NMR (500 MHz, CDCl3) δ8.09 (dd, J=7.8, 0.85 Hz, 1H), 7.70 (dd, J=4.9, 1.1 Hz, 1H), 7.67 (td, J=7.5, 1.3 Hz, 1H), 7.58 (td, J=7.8, 1.3 Hz, 1H), 7.47 (dd, J=7.5, 0.90, 1H), 7.27-7.26 (m, 1H), 7.07-7.06 (m, 1H). m.p 144-145° C.

Workup

  1. stirringafter which the reaction mixture was stirred for 3 hours at room temperature
  2. customThe reaction mixture was cautiously quenched with hydrochloric acid (0.2 M, 1 L)
  3. extractionextracted with dichloromethane
  4. extractionextracted with aqueous NaOH (1 N, 3×200 mL)
  5. filtrationthe solids were collected by filtration
  6. stirringstirred
  7. temperaturein refluxing methanol
  8. filtrationThe suspension was filtered
  9. additionwater was added to the filtrate
  10. customto crystallize 1 as a colorless solid (20.7 g, 45%)
  11. customm.p 144-145° C.

Sources & evidence

ORD record
ord-53ae5e94bf874d3cac512981bf01d3f8
Source dataset
uspto-grants-2016_04
Patent number
US09312501B2

Reaction notes

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