Water → 7-Chloro-2-(4-fluorophenyl)pyrazolo[1,5-a]pyridine-3-carbaldehyde

HRID 1797077Notes

Reaction equation

HRID 1797077 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][C:24]([F:27])=[CH:23][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][C:24]([F:27])=[CH:23][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 111841947-Chloro-2-(4-fluorophenyl)pyrazolo[1,5-a]pyridine

Product 1

HCID 221748437-Chloro-2-(4-fluorophenyl)pyrazolo[1,5-a]pyridine-3-carbaldehydeYield 95%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

N,N-Dimethylformamide (100 mL) was cooled to 0° C. and treated with phosphorous oxychloride (5.7 mL, 60.8 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-(4-fluorophenyl)pyrazolo[1,5-a]pyridine (10.0 g, 40.5 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-(4-fluorophenyl)pyrazolo[1,5-a]pyridine-3-carbaldehyde (10.6 g, 95%) as a fluffy white solid. 1H NMR (CDCl3): δ 10.07 (s, 1 H), 8.37 (d, 1 H), 7.78 (m, 2 H), 7.48 (t, 1 H), 7.20 (m, 3 H); 19F NMR (CDCl3) δ −111.25; MS m/z 275 (M+1); Anal. Calcd for C14H8ClFN2O: C, 61.22; H, 2.94; N, 10.20. Found: C, 61.34; H, 2.90; N, 10.15; mp 212–213° C. (decomp.).

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-f82e0e678dcb48099af6bd42ee0ab3ed
Source dataset
uspto-grants-2006_04
Patent number
US07034030B2

Reaction notes

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