Water → methyl 1-(3-chloropyridin-2-yl)-3-(oxiran-2-yl)-1H-pyrazole-5-carboxylate

HRID 1630674Notes

Reaction equation

HRID 1630674 reaction equation
[Cl:1][C:2]1[C:3]([N:8]2[C:12]([C:13]([O:15][CH3:16])=[O:14])=[CH:11][C:10]([CH:17]=[O:18])=[N:9]2)=[N:4][CH:5]=[CH:6][CH:7]=1.[I-].[CH3:20][S+](C)C.CC([O-])(C)C.[K+].O>CS(C)=O>[Cl:1][C:2]1[C:3]([N:8]2[C:12]([C:13]([O:15][CH3:16])=[O:14])=[CH:11][C:10]([CH:17]3[CH2:20][O:18]3)=[N:9]2)=[N:4][CH:5]=[CH:6][CH:7]=1

Participants

6

Reactant 4

HCID 962WaterHCID 75127Trimethylsulfonium iodideHCID 23665647Potassium tert-butoxideHCID 86661390HCID 86661390, compound

Product 1

HCID 86661393methyl 1-(3-chloropyridin-2-yl)-3-(oxiran-2-yl)-1H-pyrazole-5-carboxylateYield 21%

Reagents, catalysts & solvents 1

HCID 679Dimethyl SulfoxideSolvent2×

Procedure

5.00 g (18.8 mmol) of methyl 1-(3-chloropyridin-2-yl)-3-formyl-1H-pyrazole-5-carboxylate (known from WO 2006/000336) and 5.76 g (28.2 mmol) of trimethylsulphonium iodide were initially charged in 12.5 ml of dimethyl sulphoxide, and 2.64 g (23.5 mmol) of t-BuOK in 12.5 ml of dimethyl sulphoxide were added dropwise at room temperature. After 1.5 hours of stirring at room temperature, 60 ml of water were carefully added dropwise with ice cooling, whereupon the reaction mixture was extracted repeatedly with ethyl acetate. The combined organic phases were washed three times with water and then dried over magnesium sulphate. The solvent was distilled off under reduced pressure and the residue was chromatographed on silica gel, which gave 1.10 g (21% of theory) of methyl 1-(3-chloropyridin-2-yl)-3-(oxiran-2-yl)-1H-pyrazole-5-carboxylate. (logP: 1.67; MH+: 280.0; 1H-NMR (400 MHz, CD3CN, δ, ppm): 3.10 (m, 2H), 3.71 (s, 3H), 3.98 (s, 1H), 6.92 (s, 1H), 7.56 (m, 1H), 8.07 (m, 1H), 8.51 (m, 1H).)

Workup

  1. extractionwas extracted repeatedly with ethyl acetate
  2. washThe combined organic phases were washed three times with water
  3. dry with materialdried over magnesium sulphate
  4. distillationThe solvent was distilled off under reduced pressure
  5. customthe residue was chromatographed on silica gel, which

Sources & evidence

ORD record
ord-a85167f3bd064b518f00f3889eee788c
Source dataset
uspto-grants-2014_07
Patent number
US08791139B2

Reaction notes

Loading…