benzofurans and salicylaldehyde

Different benzofuran derivatives are synthesized via a catalyst-free reaction between nitroepoxides and salicylaldehydes. In the employed methodology, K

Topics: Aldehydes; Benzofurans; Catalysis

Two salicylaldehyde derivatives (1 and 2), a hydroxymethylphenol (3), five dihydroisobenzofuran (4-8) derivatives, and a 5-chloro-3-deoxyisoochracinic acid (9), together with a known 3-deoxyisoochracinic acid (10) were isolated from the marine fungus Zopfiella marina BCC 18240 (or NBRC 30420). The structures of these compounds were elucidated by extensive spectroscopic analysis. Compound 1 showed weak antituberculous activity against Mycobacterium tuberculosis H37Ra, and antibacterial activity against Bacillus cereus with MIC values of 25 and 12.5 μg/mL, respectively.

Topics: Aldehydes; Anti-Bacterial Agents; Bacillus cereus; Benzofurans; Fungi; Marine Biology; Microbial Sensitivity Tests; Molecular Structure; Mycobacterium tuberculosis; Spectrum Analysis

We report the development of a concise method of synthesizing possible cyclooxygenase (COX) inhibitor BRL-37959, which is believed to be a potent nonsteroidal anti-inflammatory drug (NSAID). The four-step synthesis greatly increased the efficiency of compound production from commercially available salicylaldehydes. The synthesis involved an optimized, bismuth(III) trifluoromethanesulfonate catalyzed benzoylation of a benzofuran ring.

Topics: Acylation; Aldehydes; Anti-Inflammatory Agents, Non-Steroidal; Benzofurans; Bismuth; Catalysis; Cyclooxygenase Inhibitors; Microwaves; Temperature

An organocatalytic cascade synthesis of 3-arylcoumarins has been developed. Mediated by 1,8-diazabicyclo[5,4,0]-undec-7-ene or tetramethylguanidine, a number of 3-arylcoumarins were obtained in good to excellent yields via condensation-ring opening-annulation between N-Bocindolin-2-ones/benzofuran-2(3H)-ones and salicylaldehydes. This method was featured by a broad scope of reactants, mild conditions, and simple operation.

Topics: Aldehydes; Benzofurans; Bridged Bicyclo Compounds, Heterocyclic; Catalysis; Coumarins; Guanidines; Indoles; Molecular Structure

Benzofuran and 2,3-dihydrobenzofuran scaffolds are core components in a large number of biologically active natural and synthetic compounds including approved drugs. Herein, we report efficient synthetic protocols for preparation of libraries based on 3-carboxy 2-aryl benzofuran and 3-carboxy 2-aryl trans-2,3-dihydrobenzofuran scaffolds using commercially available salicylaldehydes, aryl boronic acids or halides and primary or secondary amines. The building blocks were selected to achieve variation in physicochemical properties and statistical molecular design and subsequent synthesis resulted in 54 lead-like compounds with molecular weights of 299-421 and calculated octanol/water partition coefficients of 1.9-4.7.

Topics: Aldehydes; Amination; Benzofurans; Boronic Acids; Combinatorial Chemistry Techniques; Small Molecule Libraries; Stereoisomerism

Two concise syntheses of (+/-)-frondosin B (1), an interleukin-8 receptor antagonist, have been achieved from commercially available 5-methoxysalicylaldehyde. The seven-membered ring in ketone 33, the common intermediate for both syntheses, was built by a classical Friedel-Crafts reaction. The key step of the first route was facile cationic cyclization of the vinylogous benzofuran to the trisubstituted olefin (30 --> 16 + 38) to construct a six-membered carbocycle. Although this route demonstrated the efficacy of the stepwise approach to the frondosin ring-system, it also resulted in olefinic isomers that were easily isomerized in acidic conditions. In the second route, we utilized a Diels-Alder reaction between sterically demanding diene 42 and nitroethylene to fix the double bond in its required position in the resultant dimethylcyclohexane ring. A third total synthesis was devised for the purpose of determining the absolute configuration of frondosin B. It reached diene 42, this time in the enantiomerically defined form. From this point, naturally configured frondosin B was obtained in the enantiomerically enriched form. These studies establish the absolute configuration of the secondary methyl center in frondosin B to be R.

Topics: Aldehydes; Benzofurans; Heterocyclic Compounds, 4 or More Rings; Molecular Conformation; Receptors, Interleukin-8A; Stereoisomerism