Potassium Carbonate → 5-(Tert-butyl-diphenyl-silanyloxymethyl)-2-methyl-pyrazolo[1,5-a]pyridine

HRID 216656Notes

Reaction equation

HRID 216656 reaction equation
C1(C)C=C(C)C=C(C)C=1S(O[NH2:13])(=O)=O.[C:15]([SiH2:19][O:20][C:21]([C:37]1[CH:42]=[CH:41][CH:40]=[CH:39][CH:38]=1)([C:31]1[CH:36]=[CH:35][CH:34]=[CH:33][CH:32]=1)[C:22]1[CH:27]=[CH:26][N:25]=[C:24]([C:28]#[C:29][CH3:30])[CH:23]=1)([CH3:18])([CH3:17])[CH3:16].C(=O)([O-])[O-].[K+].[K+]>C(Cl)(Cl)Cl.O>[C:15]([SiH2:19][O:20][C:21]([C:31]1[CH:36]=[CH:35][CH:34]=[CH:33][CH:32]=1)([C:37]1[CH:38]=[CH:39][CH:40]=[CH:41][CH:42]=1)[C:22]1[CH:27]=[CH:26][N:25]2[N:13]=[C:29]([CH3:30])[CH:28]=[C:24]2[CH:23]=1)([CH3:16])([CH3:17])[CH3:18]

Participants

6

Reactant 3

HCID 11430Potassium CarbonateHCID 11830845O-(2,4,6-Trimethylbenzenesulfonyl)hydroxylamineHCID 1317297504-(Tert-butyl-diphenyl-silanyloxymethyl)-2-prop-1-ynyl-pyridine

Product 1

HCID 1317297495-(Tert-butyl-diphenyl-silanyloxymethyl)-2-methyl-pyrazolo[1,5-a]pyridineYield 42%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6212ChloroformSolvent2×

Procedure

A solution of O-mesitylenesulfonylhydroxylamine (18.6 g, 77.8 mmol, 5.0 equiv) in chloroform (50 ml) is added at 0-10° C. to a solution of 4-(tert-butyl-diphenyl-silanyloxymethyl)-2-prop-1-ynyl-pyridine in chloroform (50 ml). The resulting mixture is stirred at room temperature overnight. The solvent is removed in vacuo, and N,N-dimethylformamide (50 ml) is added to the residue. Potassium carbonate (4.30 g, 31.1 mmol, 2.0 equiv) is added, and the mixture is stirred at room temperature for 2 hours. The reaction mixture is diluted with water and extracted three times with EtOAc. The combined organic layers are washed with brine, dried over Na2SO4, filtered and concentrated in vacuo. Purification via flash chromatography (gradient from hexane/EtOAc 100:0 to 30:70) affords the title compound (2.6 g, 42%). 1H NMR (400 MHz, d6-DMSO): δ=8.42 (d, J=7.1 Hz, 1H), 7.60-7.58 (m, 4H), 7.43-7.35 (m, 7H), 6.64 (dd, J=7.3/1.9 Hz, 1H), 6.27 (s, 1H), 4.71 (s, 2H), 2.30 (s, 3H), 0.99 (s, 9H). MS (ES+): 401 (M+H)+.

Workup

  1. customThe solvent is removed in vacuo, and N,N-dimethylformamide (50 ml)
  2. additionis added to the residue
  3. stirringthe mixture is stirred at room temperature for 2 hours
  4. extractionextracted three times with EtOAc
  5. washThe combined organic layers are washed with brine
  6. dry with materialdried over Na2SO4
  7. filtrationfiltered
  8. concentrationconcentrated in vacuo
  9. customPurification via flash chromatography (gradient from hexane/EtOAc 100:0 to 30:70)

Sources & evidence

ORD record
ord-4d488241359f4e8a9e4a035a4674cae1
Source dataset
uspto-grants-2012_06
Patent number
US08193236B2

Reaction notes

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