A one-pot access to pyridine/benzo fused cyclododecanes via multi-component tandem reactions

A facile syntheses of novel poly-substituted pyridine/benzo fused cyclododecane hybrid heterocycles have been achieved through one-pot multi-component tandem strategy employing cyclododecanone, aromatic aldehydes and malononitrile.     

A novel entry to xanthones by an intramolecular Diels-Alder reaction involving 2-(1,2-dichlorovinyloxy) aryl dienones

A wide array of synthetic methods are described in the literature for the preparation of xanthones—a prominent class of tricyclic molecules that occur widely in nature. Majority of these reported methods involve linking the two aromatic rings and forming the central pyrone ring using a variety of classical and non-classical cyclization strategies. In a conceptually different approach, we describe here a new xanthone synthesis wherein both the pyrone and the second aromatic rings were forged in a single step by an intramolecular cycloaddition reaction involving 2-(1,2-dichlorovinyloxy) aryldienones.     

A scalable synthesis of a histamine H3 receptor antagonist

Starting from 1-methylimidazole, a concise, scalable, three-step synthesis of the title compound is described. The required 2-chloroimidazole was prepared in very good yield by halogen-metal exchange between the 2-lithio derivative and hexachloroethane.     

Solid phase radioimmunoassay of triiodothyronine (T3) using antibody coupled carboxymethylcellulose powder

The paper describes a solid-phase radioimmunoassay for triiodothyronine (T₃) using antibody coupled to carboxymethylcellulose powder. The free carboxylic acid groups of cellulose are covalently coupled to the amino groups of the antibody using 1-ethyl-3-(3-dimethylamino-propyl) carbodiimide hydrochloride. Immobilized antibody thus prepared was used in a solid-phase radioimmunoassay of T₃. The assay has a sensitivity of 0.18 g/l, and a range of 0.18–4 g/l. Satisfactory correlation was obtained when this assay was compared with a T₃ assay based on dextran coated charcoal separation system (Y=0.95X+0.15 g/L; r=0.98).     

RP-HPLC analysis of Jirakadyarishta and chemical changes during fermentation

Jirakadyarishta, an Ayurvedic formulation prepared by the fermentation of a decoction of Cuminum cyminum (seeds) is traditionally used for intestinal disorders. RP-HPLC analysis of the decoction and the final processed formulation revealed that apigenin-7-O-[galacturonide (1 --> 4)-O-glucoside] and luteolin-4'-O-glucoside-7-O-galacturonide) were the two major constituents of the decoction of C. cyminum. Selective hydrolysis of 7-O-glucosides of luteolin and apigenin during fermentation resulted in an increase in the amount of luteolin and apigenin. The 4'-O-glucoside-7-O-galacturonide of luteolin and galacturonide derivative of apigenin were not hydrolyzed during fermentation. Monomeric phenolics, together with 5-hydroxymethyl furfural (5-HMF), were also introduced into the formulation through the jaggery and other plant materials during fermentation. This communication highlights the importance of the ancient processing methods used in Ayurveda.     

A facile domino protocol for the regioselective synthesis and discovery of novel 2-amino-5-arylthieno-[2,3-b]thiophenes as antimycobacterial agents

A series of novel 2-amino-5-arylthieno[2,3-b]thiophenes has been synthesized regioselectively from the reaction of 5-aryldihydro-3(2H)-thiophenones with ethyl cyanoacetate/malononitrile and sulfur powder in the presence of morpholine under thermal as well as microwave irradiation conditions. This transformation presumably occurs via domino Gewald reaction-dehydrogenation sequence. The 2-amino-5-arylthieno[2,3-b]thiophenes were evaluated for their in vitro activity against Mycobacterium tuberculosis H37Rv (MTB) and multi-drug resistant M. tuberculosis (MDR-TB). Among 12 compounds screened, ethyl 2-amino-5-(1-naphthyl)thieno[2,3-b]thiophene-3-carboxylate was found to be the most active compound with MIC of 1.1 μM against MTB and MDR-TB.