Cornforth reagent → 3-[2-(2-Oxocyclohexyl)-3-oxo-2,3-dihydropyridazin-6-yl]-2-phenylpyrazolo[1,5-a]pyridine

HRID 965346Notes

Reaction equation

HRID 965346 reaction equation
[OH:1][C@@H:2]1[CH2:7][CH2:6][CH2:5][CH2:4][C@H:3]1[N:8]1[C:13](=[O:14])[CH:12]=[CH:11][C:10]([C:15]2[C:16]([C:24]3[CH:29]=[CH:28][CH:27]=[CH:26][CH:25]=3)=[N:17][N:18]3[CH:23]=[CH:22][CH:21]=[CH:20][C:19]=23)=[N:9]1.[Cr](O[Cr]([O-])(=O)=O)([O-])(=O)=O.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1>ClCCl>[O:1]=[C:2]1[CH2:7][CH2:6][CH2:5][CH2:4][CH:3]1[N:8]1[C:13](=[O:14])[CH:12]=[CH:11][C:10]([C:15]2[C:16]([C:24]3[CH:25]=[CH:26][CH:27]=[CH:28][CH:29]=3)=[N:17][N:18]3[CH:23]=[CH:22][CH:21]=[CH:20][C:19]=23)=[N:9]1

Participants

4

Reactant 2

HCID 2724130Cornforth reagentHCID 54253144trans-3-[2-(2-Hydroxycyclohexyl)-3-oxo-2,3-dihydropyridazin-6-yl]-2-phenylpyrazolo[1,5-a]-pyridine

Product 1

HCID 110690413-[2-(2-Oxocyclohexyl)-3-oxo-2,3-dihydropyridazin-6-yl]-2-phenylpyrazolo[1,5-a]pyridineYield 74.6%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of trans-3-[2-(2-hydroxycyclohexyl)-3-oxo-2,3-dihydropyridazin-6-yl]-2-phenylpyrazolo[1,5-a]-pyridine (157 mg) in 20 ml of dichloromethane was added pyridinium dichromate (307 mg) and molecular sieves 4A (144 mg) at 5° C. The reaction mixture was allowed to stir at room temperature for 28.5 hours. Insoluble material was filtered off using celite and the filtrate was washed with 1N hydrochloric acid (10 ml), saturated aqueous sodium bicarbonate (10 ml), and brine (10 ml), dried over sodium sulfate, and concentrated in vacuo. The crude material was purified by column chromatography on silica gel (2 g) eluted with a mixture of dichloromethane and ethyl acetate (4:1) to give 3-[2-(2-oxocyclohexyl)-3-oxo-2,3-dihydropyridazin-6-yl]-2-phenylpyrazolo[1,5-a]pyridine (116.5 mg). The nmr spectrum for this compound was identical with that of the authentic sample prepared by the method described in Example 2.

Workup

  1. filtrationInsoluble material was filtered off
  2. washthe filtrate was washed with 1N hydrochloric acid (10 ml), saturated aqueous sodium bicarbonate (10 ml), and brine (10 ml)
  3. dry with materialdried over sodium sulfate
  4. concentrationconcentrated in vacuo
  5. customThe crude material was purified by column chromatography on silica gel (2 g)
  6. washeluted with a mixture of dichloromethane and ethyl acetate (4:1)

Sources & evidence

ORD record
ord-b71ae045560b44f9ad900aa32d7aeafb
Source dataset
uspto-grants-1998_06
Patent number
US05773530

Reaction notes

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