1,5-dimethyl-1H-pyrazole-4-carbaldehyde → (NE)-N-[(1,5-dimethylpyrazol-4-yl)methylidene]-2-methylpropane-2-sulfinamide

HRID 2425541Notes

Reaction equation

HRID 2425541 reaction equation
[CH3:1][N:2]1[C:6]([CH3:7])=[C:5]([CH:8]=O)[CH:4]=[N:3]1.[C:10]([S:14]([NH2:16])=[O:15])([CH3:13])([CH3:12])[CH3:11]>C1COCC1.[Cl-].[Na+].O>[CH3:1][N:2]1[C:6]([CH3:7])=[C:5](/[CH:8]=[N:16]/[S:14]([C:10]([CH3:13])([CH3:12])[CH3:11])=[O:15])[CH:4]=[N:3]1

Participants

5

Reactant 2

HCID 5796431,5-dimethyl-1H-pyrazole-4-carbaldehydeHCID 3382465Tert-Butanesulfinamide

Product 1

HCID 87300965(NE)-N-[(1,5-dimethylpyrazol-4-yl)methylidene]-2-methylpropane-2-sulfinamideYield 97%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 57417360Sodium chloride; waterSolvent

Procedure

A mixture of 1,5-dimethyl-1H-pyrazole-4-carbaldehyde (Zhumal Obshchei Khimii 1980, 50, 2370-5, 2.0 g, 16.1 mmol), tert-butylsulfinamide (2.05 g, 16.9 mmol), and Ti(OEt)4 (6.76 ml, 32.2 mmol) in THF (32 ml) was heated under reflux for 18 h under nitrogen. After being cooled to rt, the mixture was poured into brine (32 ml) with stirring. The resulting suspension was filtered through a plug of Celite, and the filter cake was washed with EtOAc. The filtrate was transferred to a separation funnel, and organic layer was washed with brine. Then the aqueous layer was washed with EtOAc and the combined organic extracts were dried over Na2SO4, and concentrated in vacuo. The crude material was purified by silica gel chromatography (CH2Cl2:MeOH=50:1-30:1) to give the desired product as a white solid (3.55 g, 97% yield). 1H NMR (300 MHz, CDCl3) δ 1.23 (9H, s), 2.52 (3H, s), 3.83 (3H, s), 7.81 (1H, s), 8.49 (1H, s). MS (ESI) m/z 228 (M+H)+

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 18 h under nitrogen
  3. filtrationThe resulting suspension was filtered through a plug of Celite
  4. washthe filter cake was washed with EtOAc
  5. customThe filtrate was transferred to a separation funnel
  6. washorganic layer was washed with brine
  7. washThen the aqueous layer was washed with EtOAc
  8. dry with materialthe combined organic extracts were dried over Na2SO4
  9. concentrationconcentrated in vacuo
  10. customThe crude material was purified by silica gel chromatography (CH2Cl2:MeOH=50:1-30:1)

Sources & evidence

ORD record
ord-6e2124333ead431d9f3bc8ec6796d80b
Source dataset
uspto-grants-2011_06
Patent number
US07964732B2

Reaction notes

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