Trifluoromethyl Pyrazoline Medicaments

Title Pyrazoline Derivatives, Their Preparation, and Application as Medicaments 

Utility Nonsteroid Anti-inflammatory Agents with Reduced Gastrointestinal Toxicity 

THF (15 ml) was cooled to -70°C, then treated with 5 ml 2M LDA in hexane and diethylmethyl phosphonate (5 mmol) dissolved in 5 ml THF, and shaken 

Preparation of l-(4-aminosulphonylphenyl)-4,5-dihydro-5-(4-methylphenyl)-3-trifluoromethyl- lH-pyrazole 

4-(Aminosulphonyl)phenylhydrazine chlorohydrate (3.69 mmol) and the Step 1 product (3.69 mmol) were dissolved in 15 ml of acetic acid, then refluxed 3 hours, and poured over water. The mixture was extracted with EtOAc, then washed with water, dried, and concentrated. The solid was recrystallized using ethyl alcohol/petroleum ether and the product isolated in 45% yield, mp = 140-143°C. 

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