Water → 7-Chloro-2-(3-methylphenyl)pyrazolo[1,5-a]pyridine-3-carbaldehyde

HRID 861141Notes

Reaction equation

HRID 861141 reaction equation
CN(C)[CH:3]=[O:4].P(Cl)(Cl)(Cl)=O.[Cl:11][C:12]1[N:17]2[N:18]=[C:19]([C:21]3[CH:26]=[CH:25][CH:24]=[C:23]([CH3:27])[CH:22]=3)[CH:20]=[C:16]2[CH:15]=[CH:14][CH:13]=1.O>ClCCl>[Cl:11][C:12]1[N:17]2[N:18]=[C:19]([C:21]3[CH:26]=[CH:25][CH:24]=[C:23]([CH3:27])[CH:22]=3)[C:20]([CH:3]=[O:4])=[C:16]2[CH:15]=[CH:14][CH:13]=1

Participants

6

Reactant 4

HCID 962WaterHCID 6228DimethylformamideHCID 24813Phosphorus oxychlorideHCID 574447357-Chloro-2-(3-methylphenyl)pyrazolo[1,5-a]pyridine

Product 1

HCID 574947427-Chloro-2-(3-methylphenyl)pyrazolo[1,5-a]pyridine-3-carbaldehydeYield 79%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

N,N-Dimethylformamide (150 mL) was cooled to 0° C. and treated with phosphorous oxychloride (8.8 mL, 94 mmol). After the addition was complete, the mixture was warmed to room temperature and stirred for 1 hour. To this was added 7-chloro-2-(3-methylphenyl)pyrazolo[1,5-a]pyridine (16.3 g, 67 mmol) and the resultant solution was stirred overnight. Water was added, followed by dichloromethane. The aqueous layer was extracted with dichloromethane. The combined organics were washed with brine, dried over magnesium sulfate, filtered and concentrated. The residue was recrystallized from diethyl ether and hexanes to give 7-chloro-2-(3-methylphenyl)pyrazolo[1,5-a]pyridine-3-carbaldehyde (14.3 g, 79%) as a pale yellow solid. 1H NMR (CDCl3): δ 10.11 (s, 1 H), 8.41 (dd, 1H), 7.63 (s, 1H), 7.58 (d, 1H), 7.49 (dd, 1H), 7.42 (t, 1H), 7.33 (d, 1H), 7.20 (dd, 1H), 2.45 (s, 3H); MS m/z 271 (M+1).

Workup

  1. additionAfter the addition
  2. extractionThe aqueous layer was extracted with dichloromethane
  3. washThe combined organics were washed with brine
  4. dry with materialdried over magnesium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customThe residue was recrystallized from diethyl ether and hexanes

Sources & evidence

ORD record
ord-4806390e0a5c4a9bb293fec30fc63205
Source dataset
uspto-grants-2006_12
Patent number
US07153855B2

Reaction notes

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