4-Bromophenylhydrazine hydrochloride → HCID 12136728, compound

HRID 476409Notes

Reaction equation

HRID 476409 reaction equation
Cl.[Br:2][C:3]1[CH:8]=[CH:7][C:6]([NH:9]N)=[CH:5][CH:4]=1.[CH2:11]1[CH2:18][C:16](=O)[C:14](=O)[CH2:13][CH2:12]1>C(O)C.C(O)(=O)C>[Br:2][C:3]1[CH:8]=[CH:7][C:6]2[NH:9][C:13]3[C:12](=[CH:11][CH:18]=[C:16]4[C:14]=3[NH:9][C:6]3[C:5]4=[CH:4][C:3]([Br:2])=[CH:8][CH:7]=3)[C:5]=2[CH:4]=1

Participants

5

Reactant 2

HCID 121574-Bromophenylhydrazine hydrochloride4×HCID 130061,2-Cyclohexanedione

Product 1

HCID 12136728HCID 12136728, compoundYield 29.7%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidCatalystHCID 702EthanolSolvent2×

Procedure

4-Bromophenylhydrazine hydrochloride (99%; 10.44 g, 1 eq) is introduced into a solution of 1,2-cyclohexadione (98%; 5.4 g, 1 eq) in absolute ethanol (50 ml). After adding 20 drops of glacial acetic acid, the mixture is stirred at room temperature for 1 h and then at 80° C. for 4 h. Then a further 5.3 g of 99% 4-bromophenylhydrazine hydrochloride are added to the reaction and, after a further 6 h at 80° C., another 5.3 g of 99% 4-bromophenylhydrazine hydrochloride are added. The reaction is stirred overnight. After 22 h, the mixture becomes viscous, so 150 ml of absolute ethanol and a further 3 g of 99% 4-bromophenylhydrazine hydrochloride are added. After a further 2 h at 80° C., the mixture is worked up. For this purpose, the solvent is distilled off. The residue is introduced gradually into polyphosphoric acid (50 g), heated to 120° C. and stirred for 1 h. The reaction output is added cautiously to ice-water and neutralized with 2M NaOH. The precipitate is filtered off and washed with distilled water. The residue is dried under reduced pressure. After recrystallization in glacial acetic acid, 5.8 g are obtained. Yield: 29.7%

Workup

  1. waitat 80° C. for 4 h
  2. stirringThe reaction is stirred overnight
  3. waitAfter 22 h
  4. waitAfter a further 2 h at 80° C.
  5. distillationFor this purpose, the solvent is distilled off
  6. additionThe residue is introduced gradually into polyphosphoric acid (50 g)
  7. temperatureheated to 120° C.
  8. stirringstirred for 1 h
  9. additionThe reaction output is added cautiously to ice-water and neutralized with 2M NaOH
  10. filtrationThe precipitate is filtered off
  11. washwashed with distilled water
  12. customThe residue is dried under reduced pressure
  13. customAfter recrystallization in glacial acetic acid
  14. custom5.8 g are obtained

Sources & evidence

ORD record
ord-f89dc54d152348659dc8e71883e675cb
Source dataset
uspto-grants-2014_01
Patent number
US08637857B2

Reaction notes

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