The development of multicomponent reactions (MCRs) designed to produce elaborate biologically active compounds has become an important area of research in organic, combinatorial, and medicinal chemistry. A comparative study of the synthesis of new bis-spiro-oxindolo(pyrrolizidines/pyrrolidines) ring systems by the cycloaddition of azomethine ylides generated by a decarboxylative route from sarc...

Commercial dehydroacetic acid was converted into 4-hydroxy-6-methylpyridin-2(1H)-one (3), which was then condensed with several aliphatic aldehydes to produce seven new title compounds in variable yields (35-92%). Reaction of 3 with alpha,beta-unsaturated aldehydes resulted in the formation of condensed pyran derivatives 4g' and 4h'. A mechanism is proposed to explain the formation of such comp...

We report the synthesis and the optoelectronic characterization of three new 4H-pyran-4-ylidene and thiazole derivatives (pyt) as metal-free organic dyes for solid-state dye-sensitized solar cells (DSSCs). We investigate the performance and the long-term stability of devices employing pyt dyes functionalized with carboxylic and phosphonic acids as TiO2 anchoring groups. In contrast to reports o...

The asymmetric unit of the title compound, C(25)H(22)OS, comprises two similar 4-(4-methoxy-phen-yl)-4-methyl-2,6-diphenyl-4H-thio-pyran mol-ecules. In each, the six-membered thio-pyran ring adopts a planar conformation (r.m.s. deviation of 0.041Å for the ring in one mol-ecule and 0.008 Å in the other). The methoxy-phenyl substituent is in a pseudo-axial position. The crystal studied is an inve...

The binding of three closely related chelators: 5-hydroxy-2-methyl-4H-pyran-4-thione (allothiomaltol, ATM), 3-hydroxy-2-methyl-4H-pyran-4-thione (thiomaltol, TM), and 3-hydroxy-4H-pyran-4-thione (thiopyromeconic acid, TPMA) to the active site of human carbonic anhydrase II (hCAII) has been investigated. Two of these ligands display a monodentate mode of coordination to the active site Zn(2+) io...

Homophthalic anhydride reacts with different aromatic amines to produce N-substituted homophthalimides. Bromination of the latter produces 4,4-dibromo-homophthalimide derivatives that can be used as precursors for spiro-derivatives. The dibromo derivatives react with different binucleophilic reagents to produce several spiro-isoquinoline derivatives. Reaction of the dibromo derivatives with mal...

greater than the response of similarly treated blanks at the 5-gg level and 400 times greater than the response of methanol to flame ionization detection (1 ,5 ) . The compound in which the methanol is to be determined, must be somewhat water soluble. Complete dissolution of the sample weight taken in the 1-ml water-urea mixture used is necessary to free the methanol for subsequent reaction. Ac...