2-Methylbenzenesulfonic acid → 3-Amino-1-(3-chloro-4-bromobenzyl)-pyrazol-5-one

HRID 1605709Notes

Reaction equation

HRID 1605709 reaction equation
[Br:1][C:2]1[CH:10]=[CH:9][C:5]([CH2:6][NH:7][NH2:8])=[CH:4][C:3]=1[Cl:11].C([O:14][C:15](=O)[CH:16]=[C:17]([NH2:21])OCC)C.C1(C)C(S(O)(=O)=O)=CC=CC=1>C(O)C>[NH2:21][C:17]1[NH:8][N:7]([CH2:6][C:5]2[CH:9]=[CH:10][C:2]([Br:1])=[C:3]([Cl:11])[CH:4]=2)[C:15](=[O:14])[CH:16]=1

Participants

5

Reactant 3

HCID 69252-Methylbenzenesulfonic acidHCID 278451beta-Aminobeta-ethoxyacrylic acid ethyl esterHCID 20495799[(4-Bromo-3-chlorophenyl)methyl]hydrazine

Product 1

HCID 203672203-Amino-1-(3-chloro-4-bromobenzyl)-pyrazol-5-one

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

48.8 g of 4-bromo-3-chlorobenzylhydrazine are added dropwise under nitrogen to a solution of 33.2 g of β-amino-β-ethoxyacrylic acid ethyl ester and 1.5 g of toluenesulphonic acid in 150 ml of ethanol. After stirring for a further two hours, the mixture was left to stand and the compound identified above began to crystallise out after four hours. It was filtered off and twice recrystallised from ethanol. Melting point: 145°-146°, 23 g (37%).

Workup

  1. waitthe mixture was left
  2. customto crystallise out after four hours
  3. filtrationIt was filtered off
  4. customtwice recrystallised from ethanol

Sources & evidence

ORD record
ord-1a3479f573c34a72bc936c38411f997a
Source dataset
uspto-grants-1976_04
Patent number
US03950528

Reaction notes

Loading…