Tetrachlorophthalic anhydride → 1-Ethyl-2-methyl-3-(2-carboxy-3,4,5,6-tetrachlorobenzoyl)indole

HRID 1449083Notes

Reaction equation

HRID 1449083 reaction equation
[Cl:1][C:2]1[C:3]([Cl:15])=[C:4]([Cl:14])[C:5]([Cl:13])=[C:6]2[C:11](=[O:12])[O:10][C:8](=[O:9])[C:7]=12.[CH2:16]([N:18]1[C:26]2[C:21](=[CH:22][CH:23]=[CH:24][CH:25]=2)[CH:20]=[C:19]1[CH3:27])[CH3:17].[Cl-].[Al+3].[Cl-].[Cl-]>C1C=CC=CC=1>[CH2:16]([N:18]1[C:26]2[C:21](=[CH:22][CH:23]=[CH:24][CH:25]=2)[C:20]([C:11]([C:6]2[C:5]([Cl:13])=[C:4]([Cl:14])[C:3]([Cl:15])=[C:2]([Cl:1])[C:7]=2[C:8]([OH:10])=[O:9])=[O:12])=[C:19]1[CH3:27])[CH3:17]

Participants

5

Reactant 3

HCID 8326Tetrachlorophthalic anhydrideHCID 1704321H-Indole, 1-ethyl-2-methyl-HCID 6451240Aluminum(III) Chloride

Product 1

HCID 197638051-Ethyl-2-methyl-3-(2-carboxy-3,4,5,6-tetrachlorobenzoyl)indoleYield 89.9%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

To a stirred suspension of 9.66 g (0.017 mole) of tetrachlorophthalic anhydride and 13.5 g (0.034 mole) of 80 percent active 1-ethyl-2-methylindole in 30 ml of benzene maintained at 0°-5° C. by means of a ice bath, 10.6 g (0.079 mole) of aluminum chloride was added in small increments. The reaction mixture was then maintained at 0° to 5° C. for an additional twenty minutes, allowed to warm to room temperature and stirred overnight. The mixture was transferred to a beaker and triturated successively with hexane, 10 percent hydrochloric acid, and lastly with 5 percent aqueous sodium hydroxide which had been heated to 70° C. The residual oil was filtered, acidified with dilute hydrochloric acid and allowed to stand overnight. On standing, the oil gave way to a solid which was collected by filtration, washed with water and dried to yield 6.8 g of 2-[(1-ethyl-2-methyl-3-indolyl)carbonyl]3,4,5,6-tetrachlorobenzoic acid (Formula VIII: R°=R1 =R2 =R3 =Cl; R5 =CH3 ; R6 =CH3CH2 ; Y1 =H), an off white solid melting at 214°-216° C. Analysis by mass spectrum showed m/e peaks at 443 (M+, Cl=35) and 398 (M30 --COOH).

Workup

  1. temperaturemaintained at 0°-5° C. by means of a ice bath
  2. temperatureThe reaction mixture was then maintained at 0° to 5° C. for an additional twenty minutes
  3. customtriturated successively with hexane, 10 percent hydrochloric acid
  4. temperaturelastly with 5 percent aqueous sodium hydroxide which had been heated to 70° C
  5. filtrationThe residual oil was filtered
  6. waitto stand overnight
  7. customthe oil gave way to a solid which
  8. filtrationwas collected by filtration
  9. washwashed with water
  10. customdried

Sources & evidence

ORD record
ord-36dd82290bed4c46b80e7fea9af13725
Source dataset
uspto-grants-1980_02
Patent number
US04189171

Reaction notes

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