Synthesis and antimicrobial evaluation of some new pyrazole, pyrazoline and chromeno[3,4-c]pyrazole derivatives

Abstract

Alguns novos derivados de pirazol-5-carbonitrila 8,9 e pirazol-5-carboxamida 13 foram sintetizados pela reação de cicloadição de nitriliminas 3,4 a α-cianocinamonitrilas 5a-f e α-cianocinamamida 12a,b, respectivamente. Por outro lado, a adição de 3,4 a α-cianocinamato de etila 14a-f leva à produção de derivados de 2-pyrazoline-5-carboxilato de etila, 15, 16. Também, a cicloadição de 3,4 à 3-cianocumarina 19a ou à 3-fenilsulfonilcumarina 19b ou à 3-bromocumarina 19c leva à produção de derivados do cromeno[3,4-c]pirazol-4(3H)-ona, 20. A cicloadição de 3,4 à 3-acetilcumarina, 22 e 3-benzoilcumarina, 23, produz o correspondente diidrocromeno [3,4-c] pirazol-4(3H)-ona, 24 e 25, respectivamente. A oxidação de 24 e 25 produz 20. A maioria dos compostos preparados mostrou boa a moderada atividade antibacteriana e antifúngica.Some new pyrazole-5-carbonitrile derivatives 8,9 and pyrazole-5-carboxamide 13 were synthesized by the cycloaddition reaction of nitrilimines 3,4 to α-cyanocinnamonitriles 5a-f and α-cyanocinnamamide 12a,b respectively. On the other hand 3,4 add to ethyl α-cyanocinnamate 14a-f to give ethyl 2-pyrazoline-5-carboxylate derivatives 15,16. Also, cycloaddition of 3,4 to 3-cyanocoumarin 19a or 3-phenylsulphonylcoumarin 19b or 3-bromocoumarin 19c give chromeno [3,4-c]pyrazol-4(3H)-one derivatives 20. In the same direction, the cycloaddition of 3,4 to 3-acetylcoumarin 22 and 3-benzoylcoumarin 23 gives the corresponding dihydrochromeno[3,4-] pyrazol-4(3H)-one 24 and 25 respectively. Oxidation of 24 and 25 give 20. Most of the prepared compounds showed good to moderate antibacterial and antifungal activities.

Synthesis and biological evaluation of modified purine homo-N-nucleosides containing pyrazole or 2-pyrazoline moiety

“…In particular, pyrazoline derivatives have antimicrobial, anticancer, antiviral, anti-inflammatory 20 , antidepressant 21 , anticonvulsant 22 , antiamoebic 23 activity. The pyrazole derivatives present 19 analgesic, hypoglycemic, antibacterial, antiinflammatory, insecticidal, anti-influenza virus 24 , antimicrobial 25 activity. Pyrazolines are prepared mainly by cyclization of chalcones with hydrazines 16,20,23 , from 1,3-dipolar cycloaddition reactions of nitrile imines to alkenes 26 by heating 27 or under microwaves 28 or from the cyclocondensation of hydrazines with 1,3-dihalides under MW irradiation 29 .…”

“…Pyrazolines are prepared mainly by cyclization of chalcones with hydrazines 16,20,23 , from 1,3-dipolar cycloaddition reactions of nitrile imines to alkenes 26 by heating 27 or under microwaves 28 or from the cyclocondensation of hydrazines with 1,3-dihalides under MW irradiation 29 . Pyrazoles are synthesized mainly by the reaction of hydrazines with b-difunctional compounds 30 , from tosylhydrazones of a,b-unsaturated ketones under MW irradiation 31 and by 1,3-dipolar cycloaddition reactions of tosylhydrazone salts 32,33 or nitrile imines 25 with alkynes. In continuation to our work in the field of modified homo-N-nucleosides, we present here the reactions of 9-allyl-6-chloropurine with nitrile imines under MW irradiation and the replacement of chlorine by amines in the above products (Schemes 1 and 2).…”

Synthesis and Biological Activity Evaluation of Some New Heterocyclic Spirocompounds with Imidazolinone and Pyrazoline Moieties

“…Spiro compounds have also been recently used as antioxidants (Sarma et al, 2010;Shimakawa et al, 2003). Also, the pyrazoline derivatives are very interesting compounds due to their important role for the antifungal (Korgaokar et al, 1996;Abunada et al, 2009), antidepressant (Palaska et al, 2003;Rajendra et al, 2005;Ozdemir et al, 2007;Ruhogluo et al, 2005), anticonvulsant (Ozdemir et al, 2007;Ruhogluo et al, 2005), anti-inflammatory (Karabasanagouda et al, 2009), antibacterial (Abunada et al, 2009;Nauduri & Reddy, 1998) and anti-tumor (Taylor & Patel, 1992) activity. Besides, it is known that the imidazolinone derivatives are associated with a wide range of therapeutic activities such as anticonvulsant (Godefroi & Platje, 1972), potent CNS depressant, (Harfenist et al, 1978).…”

Reaction of thiocarboxanilide derivatives of 2-phenylimino-3-phenyl-4-thiazolidinone and 1,3-diphenyl-2-thioxo-4-imidazolone with hydrazonoyl halides and active chloromethylene compounds

“…Some workers have recognized 5-imidazolone as having anticancer activity [20]. Prompted by these findings and due to our interest in the synthesis of new heterocyclic compounds with potential biological activities [23][24][25][26] and in continuation of our work on the synthesis of hetaryl-ylidene derivatives [27][28][29], we report herein the synthesis of some new 1,3,4-thiadiazoline-(thiazoline)-2-hetarylylidene derivatives that might be of pharmacological importance.…”