Ammonia → 4-Chloro-2,6-diphenyl-2H-pyrazolo[3,4-b]pyridine

HRID 65996Notes

Reaction equation

HRID 65996 reaction equation
[C:1]1([N:7]2[CH:15]=[C:14]3[C:9]([N:10]=[C:11]([C:17]4[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=4)[CH:12]=[C:13]3O)=[N:8]2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.P(Cl)(Cl)([Cl:25])=O.N>>[Cl:25][C:13]1[C:14]2[C:9](=[N:8][N:7]([C:1]3[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=3)[CH:15]=2)[N:10]=[C:11]([C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)[CH:12]=1

Participants

4

Reactant 3

HCID 222AmmoniaHCID 24813Phosphorus oxychlorideHCID 178515555HCID 178515555, compound

Product 1

HCID 227568644-Chloro-2,6-diphenyl-2H-pyrazolo[3,4-b]pyridine

Procedure

5.5 g. of 2,6-diphenyl-2H-pyrazolo[3,4-b]pyridin-4-ol (0.019 mol.) and 27.5 ml. of phosphorus oxychloride are refluxed with stirring for 90 minutes. The cooled mixture is poured onto crushed ice, then made alkaline with concentrated aqueous ammonia while adding ice. The collected 4-chloro-2,6-diphenyl-2H-pyrazolo[3,4-b]pyridine is washed with water and dried at 80°; m.p. 175°-177°. A sample, recrystallized from ethanol, melts at 176°-178°; yield: 5 g. (86%).

Workup

  1. additionThe cooled mixture is poured
  2. customonto crushed ice
  3. additionwhile adding ice
  4. washThe collected 4-chloro-2,6-diphenyl-2H-pyrazolo[3,4-b]pyridine is washed with water
  5. customdried at 80°
  6. customA sample, recrystallized from ethanol, melts at 176°-178°

Sources & evidence

ORD record
ord-9debad76e9d442c48dd3c866812d6803
Source dataset
uspto-grants-1978_12
Patent number
US04129738

Reaction notes

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