Hydrochloric Acid → 3-(3-Chloropyridazin-6-yl)-2-phenylpyrazolo[1,5-a]pyridine

HRID 276923Notes

Reaction equation

HRID 276923 reaction equation
[Cl:1][C:2]1[N:7]=[N:6][C:5]([C:8]#[C:9][C:10]2[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=2)=[CH:4][CH:3]=1.[I-].[NH2:17][N+:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1.[OH-].[Na+].Cl>[Cl-].C([N+](C)(C)C)C1C=CC=CC=1.O.ClCCl>[Cl:1][C:2]1[N:7]=[N:6][C:5]([C:8]2[C:9]([C:10]3[CH:11]=[CH:12][CH:13]=[CH:14][CH:15]=3)=[N:17][N:18]3[CH:23]=[CH:22][CH:21]=[CH:20][C:19]=23)=[CH:4][CH:3]=1

Participants

8

Reactant 4

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 2733704Pyridinium, 1-amino-, iodide (1:1)HCID 126802603-Chloro-6-(phenylethynyl)pyridazine

Product 1

HCID 151581443-(3-Chloropyridazin-6-yl)-2-phenylpyrazolo[1,5-a]pyridine

Reagents, catalysts & solvents 3

HCID 5963Benzyltrimethylammonium chlorideCatalystHCID 962WaterSolvent2×HCID 6344DichloromethaneSolvent2×

Procedure

To a two-phase mixture of 6-chloro-3-(2-phenylethynyl)pyridazine (2.3 g), N-aminopyridinium iodide (90% purity; 5.3 g), benzyltrimethylammonium chloride (0.2.0 g), dichloromethane (23 ml), and water (23 ml) was added sodium hydroxide (3.4 g) in one portion. After stirring at ambient temperature overnight, the reaction mixture was treated with concentrated hydrochloric acid followed by dilution with dichloromethane and water. The organic layer was separated, and the aqueous layer was extracted once with dichloromethane. The combined organic layers were washed with water and brine, dried over anhydrous magnesium sulfate, and concentrated in vacuo. The residue was purified by column chromatography on silica gel (elution with 25:1 dichloromethane-ethyl acetate) to give 3-(3-chloropyridazin-6-yl)-2-phenylpyrazolo[1,5-a]pyridine (0.92 g).

Workup

  1. customThe organic layer was separated
  2. extractionthe aqueous layer was extracted once with dichloromethane
  3. washThe combined organic layers were washed with water and brine
  4. dry with materialdried over anhydrous magnesium sulfate
  5. concentrationconcentrated in vacuo
  6. customThe residue was purified by column chromatography on silica gel (elution with 25:1 dichloromethane-ethyl acetate)

Sources & evidence

ORD record
ord-bf92e9a9e01343b0ad6dce274b2a6a20
Source dataset
uspto-grants-2002_03
Patent number
US06355640B1

Reaction notes

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