ChemicalBook CAS DataBase List 1,5-DIMETHYL-3-(TRIFLUOROMETHYL)-1H-PYRAZOLE

1,5-DIMETHYL-3-(TRIFLUOROMETHYL)-1H-PYRAZOLE synthesis

6synthesis methods

Product Name:1,5-DIMETHYL-3-(TRIFLUOROMETHYL)-1H-PYRAZOLE
CAS Number:79080-31-2
Molecular formula:C6H7F3N2
Molecular Weight:164.13

116-11-0 Synthesis

116-11-0
272 suppliers
$10.00/5g

60-34-4
2 suppliers
$51.79/25g

407-25-0 Synthesis

407-25-0
439 suppliers
$9.00/1g

1,5-DIMETHYL-3-(TRIFLUOROMETHYL)-1H-PYRAZOLE

79080-31-2
72 suppliers
$8.00/100mg

Yield: 83%

Reaction Conditions:

Stage #1:2-Methoxypropene;trifluoroacetic anhydride with pyridine in tert-butyl methyl ether at 0 - 5; for 0.5 h;
Stage #2:methylhydrazine in tert-butyl methyl ether at -20 - 20;

Steps:

1 Example 1; Preparation of 1,5-dimethyl-3-trifluoromethyl-1H-pyrazole
187 ml (1.32 mol) of trifluoroacetic anhydride are added dropwise to a solution of 95.4 g (1.32 mol) of isopropenyl methyl ether in 265 ml of tert-butyl methyl ether and 107 ml (1.32 mol) of pyridine at a temperature of 0° C. to +5° C. After a reaction time of 30 min at +5° C., the reaction mixture is washed with 400 ml of water and 200 ml of a saturated Na2CO3 solution. The organic phase is removed and dried over MgSO4. The solution is cooled to a temperature of -20° C. and 70.4 ml (1.32 mol) of methylhydrazine are added dropwise thereto. The reaction mixture is allowed to gradually come to room temperature, the organic phase is dried over MgSO4, and the solution is subsequently concentrated under reduced pressure. Distillation of the oily residue results in 186 g (1.13 mol; 83%) of 1,5-dimethyl-3-trifluoromethyl-1H-pyrazole (b.p.: 71° C./12 mbar).

References:

Ebenbeck, Wolfgang;Rampf, Florian;Marhold, Albrecht US2004/142820, 2004, A1 Location in patent:Page 7

10010-93-2 Synthesis