Reaktion #2514309

Reaktionsgleichung

4-chlorophenyl-1-(2,4-dichlorophenyl)-4,5-dihydro-pyrazole-3carboxylic acid chloride

5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4,5-dihydro-pyrazole-3-carboxylic acid chloride

N-aminopiperidine

triethylamine

→

N-piperidinyl-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4,5-dihydropyrazole-3-carboxamide

Ausbeute 57.0%

Lösungsmittel

methylene chloride

methylene chloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe resulting reaction mixture
2. 2
   WaschenAfterwards the reaction mixture was washed with water
3. 3
   Trocknenagain with water, dried over sodium sulfate
4. 4
   Filtrationfiltered
5. 5
   Sonstigeevaporated to dryness in a rotavapor
6. 6
   SonstigeThe resulting crude solid was crystallized from ethanol
7. 7
   SonstigeThe crystallized solid was removed via filtration
8. 8
   Einengenthe mother liquors were concentrated
9. 9
   Sonstigeto yield a second fraction of crystallized product

Vorschrift

Under nitrogen atmosphere N-aminopiperidine (0.6 mL, 5.6 mmoles) and triethylamine (4 mL) were dissolved in methylene chloride (25 mL). The resulting mixture was ice-cooled down to 0° C. and a solution of 5-(4-chlorophenyl-1-(2,4-dichlorophenyl)-4,5-dihydro-pyrazole-3carboxylic acid chloride obtained in step (c) in methylene chloride (15 mL) was added dropwise. The resulting reaction mixture was stirred at room temperature (approximately 25° C.) overnight. Afterwards the reaction mixture was washed with water, followed by a saturated aqueous solution of sodium bicarbonate, then again with water, dried over sodium sulfate, filtered and evaporated to dryness in a rotavapor. The resulting crude solid was crystallized from ethanol. The crystallized solid was removed via filtration and the mother liquors were concentrated to yield a second fraction of crystallized product. The two fractions were combined to give a total amount of 1.7 g (57% of theoretical yield) of N-piperidinyl-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4,5-dihydropyrazole-3-carboxamide having a melting point of 183-186° C.

Quelle