Acetic Anhydride → 2-(4-Aminophenyl)-2,4-dihydro-5-methyl-3H-pyrazol-3-one

HRID 362453Notes

Reaction equation

HRID 362453 reaction equation
C(OC(=O)C)(=O)C.C(OC1C=CC=CC=1NC=[C:15]1[C:19](=[O:20])[N:18]([C:21]2[CH:26]=[CH:25][C:24](S(N)(=O)=O)=[CH:23][CH:22]=2)[N:17]=[C:16]1[CH3:31])C.C[N:37](C1C=CC=CN=1)C>N1C=CC=CC=1>[NH2:37][C:24]1[CH:25]=[CH:26][C:21]([N:18]2[C:19](=[O:20])[CH2:15][C:16]([CH3:31])=[N:17]2)=[CH:22][CH:23]=1

Participants

5

Reactant 3

HCID 7918Acetic AnhydrideHCID 218852-DimethylaminopyridineHCID 178466194HCID 178466194, compound

Product 1

HCID 808152-(4-Aminophenyl)-2,4-dihydro-5-methyl-3H-pyrazol-3-one

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

0.17 ml of acetic anhydride is added dropwise to a solution of 1.0 g of 4-(4-(2-ethoxyanilinomethylene)-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl)benzenesulfonamide and 0.9 g of dimethylaminopyridine in 30 ml of pyridine while cooling in ice, and the mixture is then stirred for 10 hours. The residue obtained after concentration in vacuo is mixed with dilute hydrochloric acid, and the crystals which have separated out are filtered off with suction and triturated with ethanol.

Workup

  1. temperaturewhile cooling in ice
  2. customThe residue obtained
  3. concentrationafter concentration in vacuo
  4. additionis mixed with dilute hydrochloric acid
  5. customthe crystals which have separated out
  6. filtrationare filtered off with suction
  7. customtriturated with ethanol

Sources & evidence

ORD record
ord-b2a3a75d2d4246ac894cdd0cbd0990b3
Source dataset
uspto-grants-1999_02
Patent number
US05869516

Reaction notes

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