A new approach for the solid-phase synthesis of pyrrolo[2,1-c][1,4]benzodiazepines involving reductive cleavage

A methodology based on reductive cleavage followed by cyclization, for the solid-phase synthesis of pyrrolo[2,1-c][1,4]benzodiazepines employing DIBAL-H, is described.     

Synthesis and Antibacterial Evaluation of Benzofuran Based Di-1,2,3-triazoles

Russian Journal of General Chemistry - A series of novel benzofuran-1,2,3-triazole hybrid molecules are synthesized using the click chemistry approach. Structures of the synthesized compounds were...     

Synthesis,characterization and biological evaluation of purine nucleoside analogues

We present a convenient route for the synthesis of C6-amino-C5′-N-cyclopropyl carboxamido-C2-alkynylated purine nucleoside analogues 11a–g via Sonogashira coupling reaction. The nine step synthesis is easy to perform, employing commercially available reagents. Compound 9 is used as key intermediate for the synthesis of analogues 11a–g. Synthetic intermediates and final products are appropriately characterized by IR, ¹H NMR, ¹³C NMR and Mass. The modified nucleoside analogues 11a–g is evaluated for in vitro anticancer activity against MDA-MB-231 and Caco-2 cell lines. Screening data reveals that compounds 11b and 11e displayed potent IC₅₀ value of 7.9, 6.8 µg/mL respectively against MDA-MB-231 and of 7.5, 8.3 µg/mL respectively against Caco-2 than the standard drug doxorubicin, thus establishing the potential anti-cancer properties of these newer derivatives.     

A one-pot azido reductive tandem mono-N-alkylation employing dialkylboron triflates: online ESI-MS mechanistic investigation

An efficient one-pot reductive tandem mono-N-alkylation of both aromatic and aliphatic azides using dialkylboron triflates as alkylating agents has been examined under standardized reaction conditions. This methodology after optimization has been employed toward the syntheses of various secondary alkyl as well as aryl amines, including the synthesis of N10-butylated pyrrolo[2,1-c][1,4]benzodiazepine-5,11-diones via in situ azido reductive-cyclization process. This protocol is particularly attractive to provide an environmentally benign and practical method for mono-N-alkylation from organic azides without the use of toxic catalysts or corrosive alkylating agents. In addition, the mechanistic aspects have been investigated and the intermediates associated with this selective transformation have been intercepted and characterized by online monitoring of the reaction by ESI-MS/MS.     

Enantioselective total syntheses of ropivacaine and its analogues

An alternative asymmetric synthesis of ropivacaine and analogues employing the ‘cation pool’ strategy and host/guest supramolecular co-catalysis approach is presented. In this study, chiral auxiliaries, several soft nucleophiles as well as one-pot conditions for anodic oxidation, followed by nucleophilic addition, have been applied.     

Kumada cross coupling reaction based synthesis,antimicrobial and computational studies of 6-aryl-2-phenyl-3-methylquinazolin-4(3<Emphasis Type="Italic">H</Emphasis>)-ones

Nickel catalyzed Kumada cross coupling reaction, a novel synthetic method for the synthesis of 6-aryl-2-phenyl-3-methylquinazolin-4(3H)-ones (6a–6i), was carried out by condensing 6-iodo-2-phenyl-3-methyl-quinazolin-4(3H)-one (4) with various 6-aryl/heteroaryl Grignard reagents. Molecular properties of compounds 4 and 6a–6i were studied using semiempirical PM3 computational method. The optimized geometry of the product 6 indicated that the aryl group at the position 6 was not coplanar with respect to either quinazolinone ring or phenyl group at 2 position. Compounds 6a–6i were screened for their activity against bacteria and fungi.     

Synthesis and Antibacterial Activity of Some {6-[(1H-1,2,3-Triazol-4-yl)methoxy]-3-methylbenzofuran-2-yl}(4-bromophenyl)methanone Derivatives

Russian Journal of General Chemistry - A series of novel benzofuran?1,2,3-triazole hybrid heterocyclic molecules were synthesized using a click chemistry approach. The structure of the...     

A facile intramolecular azido/amido reductive cyclization approach: synthesis of pyrrolobenzodiazepines and their dimers

A new synthetic pathway has been developed for the preparation of imine-containing pyrrolo[2,1-c][1,4]benzodiazepines (PBDs) and their dimers. Selective reduction of aromatic azides as well as aliphatic amides in a single step leading to an intramolecular reductive cyclization process by employing LiAlH₄ or LiBH₄ provides the cyclized imines.