Trityl chloride → 6-chloro-1-trityl-1H-pyrazolo[4,3-c]pyridine

HRID 571390Notes

Reaction equation

HRID 571390 reaction equation
[Cl:1][C:2]1[N:7]=[CH:6][C:5]2[CH:8]=[N:9][NH:10][C:4]=2[CH:3]=1.[H-].[Na+].[C:13](Cl)([C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1)([C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1)[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1>C1COCC1>[Cl:1][C:2]1[N:7]=[CH:6][C:5]2[CH:8]=[N:9][N:10]([C:13]([C:14]3[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=3)([C:26]3[CH:27]=[CH:28][CH:29]=[CH:30][CH:31]=3)[C:20]3[CH:21]=[CH:22][CH:23]=[CH:24][CH:25]=3)[C:4]=2[CH:3]=1

Participants

5

Reactant 3

HCID 6456Trityl chlorideHCID 24758Sodium hydrideHCID 569321096-Chloro-1H-pyrazolo(4,3-c)pyridine

Product 1

HCID 895260086-chloro-1-trityl-1H-pyrazolo[4,3-c]pyridineYield 53.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Under ice-cooling, a solution of 6-chloro-1H-pyrazolo[4,3-c]pyridine (1 g, 6.51 mmol) in THF (40 mL), was treated with NaH (60% in mineral oil; 438 mg, 10.95 mmol) and the mixture was stirred for 1 h. Trityl chloride (2.17 g, 7.81 mmol) was added and the mixture was stirred at the same temperature for 1 h and further stirred at room temperature for 3 h. The mixture was quenched with saturated NH4Cl and then extracted with EtOAc. The organic layer was washed with water, brine, dried (MgSO4) and concentrated in vacuo. To the residue was added 10 ml of DCM, some solid precipitated out. After filtration, some yellow solid was afforded. The filtrate was purified by chromatography on silica gel (0-30% EtOAc in hexane) to isolate 6-chloro-1-trityl-1H-pyrazolo[4,3-c]pyridine (1.375 g, 3.47 mmol, 53% overall) as a yellow solid. MS ESI calc'd. for C25H19ClN3 [M+H]+ 396, found 396.

Workup

  1. temperatureUnder ice-cooling
  2. stirringthe mixture was stirred at the same temperature for 1 h
  3. stirringfurther stirred at room temperature for 3 h
  4. customThe mixture was quenched with saturated NH4Cl
  5. extractionextracted with EtOAc
  6. washThe organic layer was washed with water, brine
  7. dry with materialdried (MgSO4)
  8. concentrationconcentrated in vacuo
  9. additionTo the residue was added 10 ml of DCM
  10. customsome solid precipitated out
  11. filtrationAfter filtration
  12. customsome yellow solid was afforded
  13. customThe filtrate was purified by chromatography on silica gel (0-30% EtOAc in hexane)

Sources & evidence

ORD record
ord-cf84e08293b84742988be68708c3f419
Source dataset
uspto-grants-2015_05
Patent number
US09023865B2

Reaction notes

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