Antihypertensive Agents II: Synthesis and Hypotensive Activity of Certain 1,4,5-Trisubstituted Pyrazoles

Synthesis of novel pyrazolo[3,4‐d]pyridazine, pyrido[1,2‐a]benzimidazole, pyrimido[1,2‐a]benzimidazole and triazolo[4,3‐a]pyrimidine derivatives

“…Thus, heating equimolar amounts of compound 2 with 1H-benzimidazol-2-ylacetonitrile (16) in the presence of a catalytic amount of piperidine, resulted in the formation of a single product (as examined by TLC). The structure of the isolated product was identified as 3-(5-methyl-1phenyl-1H-pyrazol-4-yl)-benzo [4,5]imidazo [1,2-a]pyridine-4-carbonitrile (18). The IR spectrum of compound 18 revealed a characteristic nitrile absorption band at 2191 cm -1 , whereas its 1 H nmr spectrum displayed two singlets at 2.24 and 8.05 due to CH 3 and pyrazole-3-CH protons, respectively, two doublets at 7.04 and 8.32 due to two pyridine protons, in addition to an aromatic multiplet in the region 7.02-7.71.…”

“…Compound 2 reacted also with 2-aminobenzimidazole (19) under the same experimental conditions and gave one isolable product identified as 4-(5-methyl-1-phenyl-1Hpyrazol-4-yl)-benzo [4,5]imidazo [1,2-a]pyrimidine (21) (Scheme 4). The IR spectrum of the reaction product revealed no bands due to amino or carbonyl functions.…”

“…On the other hand, a great deal of interest has been focused on the synthesis of functionalized pyrazole derivatives due to their synthetic and biological potentialities [4][5][6]. In continuation of our interest in the synthesis of heterocycles containing a pyrazole moiety for biological screening [7,8], we report here on the synthesis of 1-(5methyl-1-phenyl-1H-pyrazol-4-yl)-3-(N,N-dimethylamino)-2-propen-1-one (2) and its utility in 1,3-dipolar cycloaddition reactions with nitrilimines 4a-g and nitrile oxides 11a-c.…”

Ultrasound mediated green synthesis of pyrano[2,3-c]pyrazoles by using Mn doped ZrO2

“…Among them, pyrazoles annulated heterocyclic derivatives represent an important class of N-containing heterocycles being the main components of many naturally occurring products (Dastan et al, 2012). Pyrazole derivatives have occupied a vital place in drug research because of their various biological and pharmacological activities such as antibacterial (Tanitame et al, 2004), antifungal (Ragavan et al, 2010), antioxidant (Daiane et al, 2014), anticancer , antileishmanial (Faria et al, 2013), hypotensive (Arya et al, 1969), antiallergenic (Parsia et al, 1981) activities etc. Subsequently, several reports for the synthesis of these compounds have been reported including the use of TEA (Litvinov et al, 2009), Per-6-ABCD (Kuppusamy and Kasi, 2010), (Javad et al, 2012), TEABr (Kumar et al, 2007), [Dsim]AlCl 4 (Ahmad et al, 2013), FeNi 3 /SiO 2 /HPGMNP (Mohammad and Seyed, 2013), NaOH/microwave (Kathrotiya and Patel, 2012), Δ/reflux (Zonouz et al, 2012), Δ/CH 3 COOH (Gein et al, 2014), UV (Zou et al, 2011), Microwave (Sharma et al, 2016), Meglumine (Guo et al, 2013), Sproline (Khoobi et al, 2015), ZrO 2 (Saha et al, 2015), Fe 3 O 4 @SiO 2 (Soleimani et al, 2015), 1- (Bodhak et al, 2015) and SnO 2 (Paul et al, 2014).…”

Design, synthesis, and biological evaluation of N-phenylpyrazole derivatives featuring nitrogen-containing side chains as potent antitumor agents

“…In addition, pyrazoles have been used for treatment of antiangiogenesis, obesity, thrombopiotinmimetics and type 2 diabetes, because of their kinase inhibitory effects [13]. Furthermore, pyrazole and its synthetic analogs have also been reported to possess antihypertensive [14,15], and used as…”