p-Toluenesulfonic acid → Pyrazolam

HRID 918256Notes

Reaction equation

HRID 918256 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[N:11]=[C:10]([NH:12][NH2:13])[CH2:9][N:8]=[C:7]([C:14]3[CH:19]=[CH:18][CH:17]=[CH:16][N:15]=3)[C:6]=2[CH:20]=1.[CH2:21](C(CC)(CC)C([O-])([O-])[O-])[CH3:22].C1(C)C=CC(S(O)(=O)=O)=CC=1>C(O)C>[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[N:11]3[C:21]([CH3:22])=[N:13][N:12]=[C:10]3[CH2:9][N:8]=[C:7]([C:14]3[CH:19]=[CH:18][CH:17]=[CH:16][N:15]=3)[C:6]=2[CH:20]=1

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 12612400HCID 12612400, compoundHCID 21875354Triethylorthoaceate

Product 1

HCID 12562545Pyrazolam

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 2.9 g. of 7-bromo-2-hydrazino-5-(2-pyridyl)-3H-1,4-benzodiazepine, 50 ml. of ethanol, 2 ml. of triethylorthoacetate and 0.2 g. of p-toluenesulfonic acid was refluxed for 20 minutes. The solvent was evaporated under reduced pressure and the residue was partitioned between methylene chloride and aqueous sodium carbonate solution. The organic phase was dried and evaporated. Crystallization from methylene chloride/hexane yielded 8-bromo-1-methyl-6-(2-pyridyl)-4H-s-triazolo[4,3-a][1,4]benzodiazepine, having a melting point of 245°-248°. Chromatography of the mother liquor on 60 g. of silica gel using 10 percent ethanol in methylene chloride afforded additional product, m.p. 248°-250°.

Workup

  1. additionA mixture of 2.9 g
  2. customThe solvent was evaporated under reduced pressure
  3. customthe residue was partitioned between methylene chloride and aqueous sodium carbonate solution
  4. customThe organic phase was dried
  5. customevaporated
  6. customCrystallization from methylene chloride/hexane

Sources & evidence

ORD record
ord-23db7ac5d6d9491ea1ae2d033f1e7b79
Source dataset
uspto-grants-1976_07
Patent number
US03970664

Reaction notes

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