One‐Pot Syntheses of 2‐Pyrazoline Derivatives.

Abstract

Pyrazole derivativesPyrazole derivatives R 0180One-Pot Syntheses of 2-Pyrazoline Derivatives. -Treatment of hydrazinediium dithiocyanates with α,β-unsaturated ketones leads to 1-thiocarbamoyl-or 1-formyl-2-pyrazolines depending on the ketone substituents. Additionally, it is shown that (Ia) reacts with dialkylammonium thiocyanates (VII) giving bicyclooctanones. With diethylammonium thiocyanate (IX) the pyridinethione (X) is formed. With ammonium thiocyanate (XI) the pyrimidine (XII) is prepared. -(SEEBACHER*, W.; MICHL, G.; BELAJ, F.; BRUN, R.; SAF, R.; WEIS*, R.; Tetrahedron 59 (2003) 16, 2811-2819; Inst. Pharm. Chem., Karl-Franzens-Univ., A-8010 Graz, Austria; Eng.) -Jannicke 32-090

5-(3-Nitrophenyl)-3-phenyl-4,5-dihydro-1H-pyrazole-1-carbaldehyde

“…On the basis of these spectral results, the molecule was characterized as the new structure, 5-(3-nitrophenyl)-3-phenyl-4,5-dihydro-1H-pyrazole-1-carbaldehyde. N-formyl derivatives of 2-pyrazolines have been reported previously [12]. The structure of a similar compound, 3-(4-methylphenyl)-5-[4-(methylthio)phenyl]-4,5-dihydro-1H-pyrazole-1-carbaldehyde, has also been established by crystallographic method [13].…”