Synthesis, Spectroscopic Studies and X-ray Crystal Structures of New Pyrazoline and Pyrazole Derivatives

• Published in: Journal of chemical crystallography 2011-03, Vol.41 (3), p.401-408
• Main Authors: de Sousa, Gerimário F., Gatto, Claudia C., Resck, Inês S., Deflon, Victor M.
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Crystallography and Scattering Methods; Inorganic Chemistry; Organometallic Chemistry; Original Paper; Physical Chemistry
• ISSN: 1074-1542; 1572-8854
• DOI: 10.1007/s10870-010-9896-2

The synthesis and characterization of some pyrazoline compounds of 1,3-diketones with hydrazine derivatives, namely, 1-( S -benzyldithiocarbazate)-3-methyl-5-phenyl-5-hydroxypyrazoline ( 1 ); 1-(2-thiophenecarboxylic)-3-methyl-5-phenyl-5-hydroxypyrazoline ( 2 ); 1-(2-thiophenecarboxylic)-3,5-dimethyl-5-hydroxypyrazoline ( 3 ); 1-( S -benzyldithiocarbazato)-3-methyl-5-phenylpyrazole ( 4 ); 1-(2-thiophenecarboxylic)-3-methyl-5-phenylpyrazole ( 5 ) and 1-( S -benzyldithiocarbazate)-3,5-dimethylpyrazole ( 6 ) are reported. Studies by IR, ( 1 H, 13 C)-NMR spectroscopies and single crystal X-ray diffraction revealed that compounds ( 1 ) , ( 2 ) and ( 3 ) are formed as pyrazoline, whereas ( 4 ) and ( 5 ) are formed as pyrazole derivatives only under acidic conditions. Compound ( 1 ) crystallizes in orthorhombic P 2 1 2 1 2 1 , a  = 6.38960(10) Å, b  = 12.9176(3) Å, c  = 21.2552(5) Å, ( 2 ) crystallizes in monoclinic, P 2 1 / n , a  = 11.3617(2) Å, b  = 8.4988(2) Å, c  = 92.8900(10) Å and β  = 92.8900(5)°, ( 3 ) crystallizes in monoclinic, C 2/ c , a  = 15.9500(5) Å, b  = 9.3766(3) Å, c  = 16.6910(5) Å and β  = 113.825(2)°, ( 4 ) crystallizes in monoclinic, P 2 1 / c , a  = 15.228(4) Å, b  = 5.5714(13) Å, c  = 19.956(5) Å and β  = 91.575(7)° and ( 6 ) crystallizes in orthorhombic, P 2 1 2 1 2 1 , a  = 5.3920(2) Å, b  = 11.2074(5) Å, c  = 21.885(1) Å. The ( 3 ) derivative represents the first pyrazoline compound prepared from 2,4-pentanedione and characterized crystallographically. Graphical Abstract The synthesis and characterization of some pyrazoline compounds of 1,3-diketones with hydrazine derivatives, namely, 1-( S -benzyldithiocarbazate)-3-methyl-5-phenyl-5-hydroxypyrazoline ( 1 ); 1-(2-thiophenecarboxylic)-3-methyl-5-phenyl-5-hydroxypyrazoline ( 2 ); 1-(2-thiophenecarboxylic)-3,5-dimethyl-5-hydroxypyrazoline ( 3 ); 1-( S -benzyldithiocarbazato)-3-methyl-5-phenylpyrazole ( 4 ); 1-(2-thiophenecarboxylic)-3-methyl-5-phenylpyrazole ( 5 ) and 1-( S -benzyldithiocarbazate)-3,5-dimethylpyrazole ( 6 ) are reported. Studies by IR, ( 1 H, 13 C)-NMR spectroscopies and single crystal X-ray diffraction revealed that compounds ( 1 ) , ( 2 ) and ( 3 ) are formed as pyrazoline, whereas ( 4 ) and ( 5 ) are formed as pyrazole derivatives only under acidic conditions. Compound ( 1 ) crystallizes in orthorhombic P 2 1 2 1 2 1 , a  = 6.38960(10) Å, b  = 12.9176(3) Å, c  = 21.2552(5) Å, ( 2 ) crystallizes in monoclinic, P 2 1 / n , a  = 11.3617(2) Å, b  = 8.4988(2) Å, c  = 92.89