Methylhydrazine → 1-methyl-3-(trifluoromethyl)-1H-pyrazol-5-amine

HRID 871522Notes

Reaction equation

HRID 871522 reaction equation
[NH2:1]/[C:2](/OCC)=[CH:3]\[C:4](=O)[C:5]([F:8])([F:7])[F:6].[CH3:13][NH:14][NH2:15]>CCO>[CH3:13][N:14]1[C:2]([NH2:1])=[CH:3][C:4]([C:5]([F:8])([F:7])[F:6])=[N:15]1

Participants

4

Reactant 2

HCID 6061MethylhydrazineHCID 151117544-Amino-4-ethoxy-1,1,1-trifluorobut-3-en-2-one

Product 1

HCID 196233031-methyl-3-(trifluoromethyl)-1H-pyrazol-5-amineYield 82.1%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Using the procedure described in Example 161A Step 3, (E)-4-amino-4-ethoxy-1,1,1-trifluorobut-3-en-2-one (2.34 g, 12.78 mmol) and methylhydrazine (0.645 g, 14 mmol) were reacted in EtOH (10 mL) at 95° C. for 8 hours, and purified by silica gel chromatography with 30-40% EtOAc/hexane as eluants to afford 1-methyl-3-(trifluoromethyl)-1H-pyrazol-5-amine as solid (1.733 g, 68.3%). MP: 100-101° C.; 1H NMR (300 MHz, CDCl3) δ 5.80 (s, 1H), 3.71 (s, 3H), 3.62 (br, 2H); LC-MS (ESI) m/z 166 (M+H)+.

Workup

  1. custompurified by silica gel chromatography with 30-40% EtOAc/hexane as eluants

Sources & evidence

ORD record
ord-57b66e0fb5e94ada9756894cda60a077
Source dataset
uspto-grants-2015_03
Patent number
US08969587B2

Reaction notes

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