α-Pyrazolyl-Alkylphosphonates. Part. II1: A simple and Efficient Synthesis of Diethyl 1-(pyrazol-4-yl)-alkylphosphonates

Efficient one-pot protocol for diverse pyrazolylphosphonates by multi-component reactions: their antioxidant and antibacterial activities

Efficient one-pot three-component reactions of pyrazolones with arylaldehydes and triethyl phosphite were carried out in the presence of ethylenediammonium diacetate as catalyst to synthesize biologically interesting pyrazolylphosphonate derivatives. This methodology offers several significant advantages such as environmentally benign character, the use of a mild catalyst, high yields, and ease of handling. The synthesized compounds were screened for their antioxidant and antibacterial activities. The result showed that compound 4d [Formula: see text] exhibited a strong free radical scavenger toward DPPH free radicals compared with standard BHT [Formula: see text]. In addition, compounds 4e and 4p showed potent antibacterial activities against Gram-negative bacteria of E. coli and compound 4o exhibited a potent activity against Gram-positive bacteria of S. aureus compared with standard Ampicillin.

Approaches towards the synthesis of 5-aminopyrazoles

The biological and medicinal properties of 5-aminopyrazoles have prompted enormous research aimed at developing synthetic routes to these heterocyles. This review focuses on the biological properties associated with this system. Various synthetic methods developed up to 2010 for these compounds are described, particularly those that involve the reactions of β-ketonitriles, malononitrile, alkylidenemalononitriles and their derivatives with hydrazines, as well as some novel miscellaneous methods.

Synthesis, antiviral and antifungal bioactivity of 2-cyano-acrylate derivatives containing phosphonyl moieties

Alkyl 2-cyano-3-methylthio-3-phosphonylacrylates were synthesized by the reaction of alkyl 2-cyano-3,3-dimethylthioacrylates with dialkyl phosphites. The structures of the new compounds were characterized by elemental analyses, IR, 1H-, 13C- and 31P-NMR spectral data. These compounds were tested in vitro against pathogenic fungi, namely, Fusarium graminearum, Cytospora mandshurica and Fusarium oxysporum. Amongst all compounds, 2d and 2t were found to be effective against the tested fungi at 50 microg/mL. A half-leaf method was used to determine the in vivo protective, inactivation and curative efficacies of the title products against tobacco mosaic virus (TMV). Title compounds 2a and 2b were found to possess good in vivo curative, protection and inactivation effects against TMV with inhibitory rates at 500 mg/L of 60.0, 89.4 and 56.5 and 64.2, 84.2 and 61.2 %, respectively. To the best of our knowledge, this is the first report on the antiviral and antifungal activity of alkyl 2-cyano-3-methylthio-3-phosphonylacrylates.