Pyrazole → 1-(3-nitrothiophen-2-yl)-1H-pyrazole

HRID 1519958Notes

Reaction equation

HRID 1519958 reaction equation
CC(C)([O-])C.[K+].[NH:7]1[CH:11]=[CH:10][CH:9]=[N:8]1.Cl[C:13]1[S:14][CH:15]=[CH:16][C:17]=1[N+:18]([O-:20])=[O:19]>CN(C=O)C.[Cl-].[Na+].O>[N+:18]([C:17]1[CH:16]=[CH:15][S:14][C:13]=1[N:7]1[CH:11]=[CH:10][CH:9]=[N:8]1)([O-:20])=[O:19]

Participants

6

Reactant 3

HCID 1048PyrazoleHCID 2201862-Chloro-3-nitrothiopheneHCID 23665647Potassium tert-butoxide

Product 1

HCID 125544861-(3-nitrothiophen-2-yl)-1H-pyrazole

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 57417360Sodium chloride; waterSolvent

Procedure

Potassium tert-butoxide (2.28 g, 20.3 mmol) and 1H-pyrazole (2.02 g, 29.7 mmol) in DMF (50 ml) was stirred for 30 min. 2-chloro-3-nitrothiophene (2.56 g, 15.6 mmol) was added and the solution was placed into a preheated oil bath at 100° C. After stirring for 1 h, the solution was diluted with brine and extracted with diethyl ether. The combined organic extracts were dried over magnesium sulfate, filtered and concentrated under reduced pressure. The residue was flash chromatographed with 9:1, 4:1, 7:3, 3:2, and 1:1 hexane:ethyl acetate as the eluant to yield impure 1-(3-nitrothiophen-2-yl)-1H-pyrazole. Method [1] Retention time 1.52 min by HPLC (MH+196).

Workup

  1. customthe solution was placed into a preheated oil bath at 100° C
  2. extractionextracted with diethyl ether
  3. dry with materialThe combined organic extracts were dried over magnesium sulfate
  4. filtrationfiltered
  5. concentrationconcentrated under reduced pressure
  6. customchromatographed with 9:1, 4:1, 7:3, 3:2, and 1:1 hexane

Sources & evidence

ORD record
ord-73fced4bba2145fa91a5e487e75593e8
Source dataset
uspto-grants-2015_07
Patent number
US09073891B2

Reaction notes

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