Synthesis of novel benzo[4,5]imidazo[1,2-a]pyrimido- [4,5-d]pyrimidine derivatives as potent antimicrobial agents

445-453Synthesis of novel benzo[4,5]imidazo[1,2-a]pyrimido[4,5-d] pyrimidines 5/6 has been achieved by reaction of 2-amino-4-aryl-4,10-dihydrobenzo[4,5]imidazo[1,2-a]pyrimidine-3-carbonitriles 4 with formaldehyde/urea. The key intermediate 4, is obtained by reaction of 2-aminobenzaldehyde 1 with aromatic aldehyde and malononitrile by a three-component one-pot process. The newly synthesized title compounds 5/6 have been evaluated for their in vitro antimicrobial activity. Compounds 5 and 6 exhibit potent antimicrobial activity compared to that of standard drugs

A facile synthesis of 1-aryl pyrroles by Clauson-Kaas reaction using oxone as a Catalyst under microwave irradiation

A new and efficient methodology to synthesize N-substituted pyrrole derivatives by Clauson Kaas reaction employing Oxone as catalyst was developed. The transformation was performed in acetonitrile under microwave irradiation. This procedure has several advantages such as high yield, clean product formation, and short reaction time.               KEY WORDS: Synthesis, Pyrrole, Oxone, Microwave irradiation Bull. Chem. Soc. Ethiop. 2019, 33(1), 143-148DOI: https://dx.doi.org/10.4314/bcse.v33i1.14

Antifungal activity of naphthothiazoles derived from Lawsone (Lawsonia inermis)

A series of Naphtho [2,3-d] thiazole-4, 9-diones was prepared by the condensation of bromolawsone with thiosemicarbazones derived from the aldehydes and ketones in dry dimethyl formamide (DMF). The products are also obtained by the cyclization of the intermediate 2-chlorobenzaldehyde thiosemicarbazone of 1,4-napthoquinone in ethanol containing K2CO3 obtained from 2,3-dichloro naphthoquinone. These compounds showed that maximum fungicidal activity varied with substituent on the compounds of Lawsone.Key words: Lawsonia inermis, 2,3-dichloronaphthoquinones, thiosemicarbazones, naphthothiazoles, fungicidal activity, Fusarium oxysporum, Curvularia lunata

Synthesis and antimicrobial activity of 2-((4-(1H-benzo[d]imidazol-2-yl)-6-(2-ethylcyclopentyl) pyrimidin-2-yl)thio)-N-methylacetamide

It was possible to synthesise a brand new series of 2-((4-(1H-benzo[d]imidazol-2-yl)-6-(2-ethylcyclopentyl)pyrimidin-2-yl)thio)-N-methyl acetamide (4a-h). The reaction of 1-(1H-benzimidazol-2-yl)ethanone with 2-ethylcyclopentane carbaldehyde with ethanol and KOH yielded (E)-1-(1H-benzo[d]imidazol-2-yl)-3-(2-ethylcyclopentyl)prop-2-en-1-one (1a-c). All compounds shown to have antimicrobial action via pharmacological study are listed here. . Chloramphenicol and Amphotericin B, two conventional antibiotics, were compared to the antibacterial and antifungal properties of synthetic compounds. It was discovered that Schlenter products had spectroscopic properties worth investigating

Synthesis and antimicrobial activity of novel benzo[4', 5']-imidazo[1',2':1,2]pyrrolo[3,4-b]isoxazolo[4,5-e]pyridines

174-183Synthesis of novel benzo [4',5'] imidazo [1',2':1,2] pyrrolo [3,4-b] isoxazolo [4,5-e] pyridines 8 has been achieved by reaction of 1-(prop-2-yn-1-yl)-1H-benzo [d] imidazo-2-carbaldehydes 5 with 5-amino -3-methylisoxazole 6 in presence of InCl3 in CH3CN media, followed by reaction of imine 7 with BF3.Et2O in DCE at 80°C. The newly synthesized title compounds 8 have been evaluated for their in vitro antimicrobial activity. Compounds 8 exhibit potent antimicrobial activity compared to that of standard drugs

Synthesis of novel benzo[4,5]imidazo[1,2-a]pyrimido- [4,5-d]pyrimidine derivatives as potent antimicrobial agents

Synthesis of novel benzo[4,5]imidazo[1,2-a]pyrimido[4,5-d] pyrimidines 5/6 has been achieved by reaction of 2-amino-4-aryl-4,10-dihydrobenzo[4,5]imidazo[1,2-a]pyrimidine-3-carbonitriles 4 with formaldehyde/urea. The key intermediate 4, is obtained by reaction of 2-aminobenzaldehyde 1 with aromatic aldehyde and malononitrile by a three-component one-pot process. The newly synthesized title compounds 5/6 have been evaluated for their in vitro antimicrobial activity. Compounds 5 and 6 exhibit potent antimicrobial activity compared to that of standard drugs

A simple and efficient one-pot synthesis of novel benzimidazo[1,2-a]- chromeno[4,3-d] pyrimidinones catalyzed by [Et3NH][HSO4]

1418-1424A simple and efficient one-pot synthesis of novel polyheterocyclic benzimidazo[1,2-a]- chromeno[4,3-d]pyrimidinones 4 via a three-component condensation of 2-aminobenzimidazole 1, aromatic aldehydes 2 and 4-hydroxy coumarin 3 catalyzed by Bronsted acid ionic liquid triethyl ammonium hydrogen sulphate [Et3NH][HSO4] under solvent-free conditions is reported. The main advantages of this protocol are short reaction time, easy work-up, operational simplicity, and excellent yields with high purity, without intervention of chromatography

Preparation of 2-aryl-6,7-dihydroxy-8-undecyl-4H-1,3,4-benzoxadiazines

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Synthesis of 6,7-dihydroxy-3-aryl-5-undecyl-4,1,2-benzoxadiazines

1457-1461 Condensation of Embelin 1 with different aromatic acid hydra­zides 2 in glacial acetic acid to give N1-5-hydroxy-6-unde­cyl-p-benzoaquinone-2-yl)-benzohydrides 3. Reductive cycli­za­tion of the product 3 with simultaneous acetylation in situ resulted in the formation of the compound 4 1-N-acetyl-6,7-diacetyl-3-aryl-5-undecyl-4,1,2-benzoxadiazine. In the final step the compound 4 is deacetylated to give the title products 5. The structures of the newly prepared compounds have been confirmed from analytical and spectral data. Some of the compounds exhibited antibacterial and antifungal activity. </smarttagtype

Synthesis and antimicrobial activity of benzimidazolyl oxazolyl thiazolidin-4-ones and azetidin-2-ones

1042-1050A new series of 3-[4-(1H-benzo[d] imidazol-2-yl) oxazol-2-yl]-2-thiazolidin -4-ones 4 and 1-[4-(1H-benzo[d] imidazol-2-yl) oxazol-2-yl)-3-azetidin-2-ones 5 have been prepared from 2-acetyl benzimidazole 1. Compound 1 on treatment with urea in presence of I2 furnishes 4-(1H-benzo[d] imidazol-2-yl) oxazol-2-amine 2, which on condensation with aromatic aldehydes affords the corresponding Schiff bases 3. Cyclocondensation of 3 with thioglycollic acid produces the benzimidazolyl oxazolyl thiazolidin-4-ones 4, whereas, reaction of 3 with chloroacetyl chloride in presence of triethyl amine furnishes benzimidazolyl oxazolyl azetidin-2-ones 5. The structures of the newly synthesized compounds 3-5 have been elucidated on the basis of spectral (IR, 1H and 13C NMR and MS) and analytical data. The title compounds 4 and 5 have been screened for their antimicrobial activity. Some of the compounds exhibit promising antimicrobial activity