Modifications of 5,12-dihydroindolo[3,2-a]carbazole scaffold via its regioselective C2,9-formylation and C2,9-acetylation

The effective approaches for regioselective double formylation and acetylation of 5,12-dialkyl-6,7-diaryl-substituted 5,12-dihydroindolo[3,2-a]carbazoles by their treatment with dichloromethyl methyl ether in the presence of SnCl₄ or with acetyl chloride in the presence of AlCl₃ to afford the 2,9-diformyl or 2,9-diacetyl derivatives, respectively, were developed. Furthermore, new 2,9-bis(2,2-dicyanovinyl) derivatives were synthesized by the Knoevenagel condensation of diformyl-containing substrates with malononitrile, when new 2,9-bis(quinoxaline-2-yl)- and 2,9-bis(benzo[g]quinoxaline-2-yl) derivatives were formed via microwave-promoted oxidation of diacetyl-containing substrates with SeO₂ to the corresponding diglyoxals, followed by the reaction of these intermediates with o-phenylendiamine or 2,3-diaminonaphthalene, respectively. The basic optical and electrochemical properties of some 5,12-dihydroindolo[3,2-a]carbazoles were investigated.     

A consecutive one-pot two-step approach to novel trifluoromethyl-substituted bis(indolyl)methane derivatives promoted by Sc(OTf)3 and p-TSA

A one-pot two-step reaction of 3-(trifluoroacetyl)coumarin and indole afforded trifluoromethyl-substituted bis(indolyl)methane compounds containing coumarin skeleton. The atomic economic and simply manipulative reaction involved premier treatment of reaction mixtures with Sc(OTf)₃, followed by p-TSA in one-pot process. The reaction proceeded to give the title compounds in high yields (up to 95% yield).     

An Efficient and Environment Friendly Procedure for the Synthesis of Arylmethylenemalononitrile Catalyzed by Strong Base Anion‐Exchange Resin in Water

Abstract

Knoevenagel condensation of malononitrile with aromatic aldehydes catalyzed by strong base anion‐exchange resin in water results arylmethylenemalononitrile in 74–98% yield at room temperature.     

Design, synthesis and primary activity of thiomorpholine derivatives as DPP-IV inhibitors

Thirteen thiomorpholine-bearing compounds were designed and synthesized as dipeptidyl peptidase IV（DPP-IV） inhibitors, with natural and non-natural L-amino acids as the starting materials.Their structures were characterized by ¹H NMR,¹³C NMR and HR-MS.The target compounds were screened for the DPP-IV inhibition,and the preliminary SAR result was obtained.Particularly, compounds 4c,4d and 4f with good DPP-IV inhibition in vitro were further evaluated through a mouse oral glucose tolerance test （OGTT）.The preliminary result showed the potential value for further studies on those thiomorpholine-bearing compounds as DPP-IV inhibitors.     

Enzymatic Synthesis of Fructosyl Glycerol

ABSTRACT

The enzymatic synthesis of ß2-2' and ß2-1'-D- fructopyranosyl glycerol was carried out with levansucrase from Bacillus circulans or B.subtilis, using sucrose as fructosyl donor and glycerol. The specificity and efficiency of the enzyme was modified by controlling both the water and the total substrate concentrations. The products were purified by HPLC and analyzed by ¹H, ¹³C NMR and GC-MS.     

Studies on Azolylacetonitriles: The Reactivity of Thiazole-2-yl,Thiadiazol-2-yl Acetonitriles Toward Electrophilic Reagents

5-Acetyl-2-cyanomethyl-4-methylthiazole, 2-aminothiazole, and 5-N-benzoylamino-1,3,4-thiadiazole-2-yl-acetonitrile react with acetone, and malononitrile derivatives in the presence of sulfur to yield the corresponding thiophene derivatives. Also, 4-furylmethylene-2-phenyl-2-oxazolin-5-ones react with thiophenol, and/or thionaphthol to give the thiolester derivatives in one-pot synthesis. The structures of the products were based on IR, 1 H NMR, and elemental analysis.     

Synthesis of Calix[4]arene Derivatives Containing a Nucleobase and their Interaction with Complementary Nucleosides at the Air–Water Interface

Amphiphilic calix[4]arene derivatives with a nucleobase on the lower rim have been synthesized in good yields by the condensation of calix[4]arenediamine {5,11,17,23-tetra-tert-butyl-25,27-bis(2-aminoethoxy)-26,28-dihydroxycalix[4]arene} with uracilo-N-acetic acid, thymino-N-acetic acid and adenino-N-propionic acid in the presence of CDI in DMF. Monolayers of the amphiphilic calix[4]arene-nucleobase derivatives on the surface of pure water, the aqueous subphases containing complementary nucleosides, were studied by film balance measurement and relaxation experiments. LB films deposited from all subphases were investigated by UV spectra and FT-IR spectroscopy. All the results indicate that the interaction between the nucleobases in the headgroup of amphiphilic p-tert-butylcalix[4]arene derivatives and the complementary nucleosides in the subphase takes place through multiple hydrogen bonding and the nucleosides can be transferred to solid substrates along with their monolayers.     

SYNTHESIS AND ANTIBACTERIAL ACTIVITY OF SOME NEW PYRIDYL DIARYLSULFIDE AND DIARYLSULFONES

Abstract

Condensation of isonicotinaldehyde with 4-aminodiphenyl sulfides 1 and/or sulfones II gave 4-[N-[p-(diaryl/thio)]formimidoyl]-pyridine III and/or 4-[N-[p-(diarylsulfonyl)]-formimidoyl]pyridine IV. Cyclocondensation of mercaptoacetic acid on III and IV gave 3-[p-(diarylthio)]-2-(4-pyridyl)-4-thiazolidinones V and 3-[p-(diarylsulfonyl)]-2-(4-pyridyl)-4-thiazolidinones VI respectively. (Hetero/arylthio)-N-(6-methyl-2-pyridyl)-acetamides VIII have been synthesised via interaction of 6-methyl-2-chloroacetamido-pyridine VII with heterocyclic and/or aromatic mercaptans. Reaction of VII with piperidine and/or morpholine affords (IX). Biological activities of these compounds were tested.     

A Novel Synthesis of 2-Alkylthiobenzothiazoles and 2-Alkylthiobenzoxazoles

Abstract

3H-Benzothiazole-2-thione and 3H-benzoxazole-2-thione were selectively S-alkylated by use of O-alkylisoureas as the alkylating reagents. The reactions could be performed under mild reaction conditions in short reaction times, and high yields were obtained using O-primary-alkylisoureas, whereas low yields were obtained with sec- and tert-alkylisoureas.