Phenylhydrazine → HCID 58489576, compound

HRID 476412Notes

Reaction equation

HRID 476412 reaction equation
[C:1]([C:4]1[O:8][C:7]2[CH:9]=[CH:10][C:11]([Br:13])=[CH:12][C:6]=2[CH:5]=1)(=O)[CH3:2].[C:14]1([NH:20]N)[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1.[OH-].[Na+]>C(O)C.C(O)(=O)C>[Br:13][C:11]1[CH:10]=[CH:9][C:7]2[O:8][C:4]([C:1]3[NH:20][C:14]4[C:19]([CH:2]=3)=[CH:18][CH:17]=[CH:16][CH:15]=4)=[CH:5][C:6]=2[CH:12]=1

Participants

6

Reactant 3

HCID 7516Phenylhydrazine2×HCID 14798Sodium HydroxideHCID 7056701-(5-Bromo-1-benzofuran-2-yl)ethan-1-one

Product 1

HCID 58489576HCID 58489576, compound

Reagents, catalysts & solvents 2

HCID 176Acetic AcidCatalystHCID 702EthanolSolvent

Procedure

Under nitrogen, 2-acetyl-5-bromobenzo[b]furan (commercially available, 5.0 g, 1 eq.) is initially charged in absolute ethanol. Phenylhydrazine (97%; 2.33 g, 1 eq.) is introduced. 20 drops of glacial acetic acid are added to this mixture and the reaction is stirred at room temperature for 24 h. Then phenylhydrazine (97%; 0.36 g, 0.15 eq.) is added and the mixture is stirred at room temperature for a further 5 h. The solids are filtered off and washed with distilled water. Dried under reduced pressure at 65° C. This gives 6.65 g of intermediate. This is introduced gradually into polyphosphoric acid (60 g), and the mixture is heated to 120° C. and stirred for a further 1 h. 0.5 l of distilled water is cautiously added dropwise to the reaction and the mixture is stirred for a further 2 h. The suspension obtained is neutralized with 50% sodium hydroxide solution. The suspension is filtered with suction and the solids are washed with distilled water. The solids obtained are dried under reduced pressure. This gives 6.07 g of slightly contaminated product (crude yield 93%). This is used in the next stage without purification.

Workup

  1. stirringthe mixture is stirred at room temperature for a further 5 h
  2. filtrationThe solids are filtered off
  3. washwashed with distilled water
  4. customDried under reduced pressure at 65° C
  5. additionThis is introduced gradually into polyphosphoric acid (60 g)
  6. temperaturethe mixture is heated to 120° C.
  7. stirringstirred for a further 1 h
  8. addition0.5 l of distilled water is cautiously added dropwise to the reaction
  9. stirringthe mixture is stirred for a further 2 h
  10. customThe suspension obtained
  11. filtrationThe suspension is filtered with suction
  12. washthe solids are washed with distilled water
  13. customThe solids obtained
  14. customare dried under reduced pressure
  15. customThis is used in the next stage without purification

Sources & evidence

ORD record
ord-cfa40abd03ef47dab5ee06903821a1d7
Source dataset
uspto-grants-2014_01
Patent number
US08637857B2

Reaction notes

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