Synthesis and Bioactivity of Pyrazole Acyl Thiourea Derivatives

• Main Authors: Jian Wu, Linhong Jin, Qing Shi, Deyu Hu, Ming He, Zhuo Chen
• Format: Article
• Language: English
• Published: MDPI AG 2012-05-01
• Series: Molecules
• Subjects: pyrazole acyl thiourea derivatives; synthesis; antifungal activity; antiviral activity
• Online Access: http://www.mdpi.com/1420-3049/17/5/5139

Sixteen novel pyrazole acyl thiourea derivatives <strong>6</strong> were synthesized from monomethylhydrazine (phenylhydrazine) and ethyl acetoacetate. The key 5-chloro-3-methyl-1-substituted-1<em>H</em>-pyrazole-4-carbonyl chloride intermediates <strong>4</strong> were first generated in four steps through cyclization, formylation, oxidation and acylation. Thess were then reacted with ammonium thiocyanate in the presence of PEG-400 to afford 5-chloro-3-methyl-1-substituted-1<em>H</em>-pyrazole-4-carbonyl isothiocyanates <strong>5</strong>. Subsequent reaction with fluorinated aromatic amines resulted in the formation of the title compounds.<strong> </strong>The synthesized compound were unequivocally characterized by IR, <sup>1</sup>H-NMR, <sup>13</sup>C-NMR and elemental analysis and some of the synthesized compounds displayed good antifungal activities against <em>Gibberella zeae</em>, <em>Fusarium oxysporum</em>, <em>Cytospora mandshurica</em> and anti-TMV activity in preliminary antifungal activity tests.