We describe a new method for measuring total bilirubin in serum. Nonionic, cationic, or anionic surfactants can be used as solubilizing agents to promote the diazo coupling of indirect-reacting bilirubin. A representative surfactant-azobilirubin system is illustrated, in which absorbance is maximum at 560 nm and linear to a concentration of 200 mg of bilirubin per liter. At pH 2.5 and in the pr...

The solid-solid reactions of thiosemicarbazide with 4-formylantipyrine, 2-acetylpyrrole and camphor were performed to afford the thiosemicarbazones 1-3 which underwent hetero-cyclization with phenacyl bromide to furnish the corresponding thiazole derivatives 4-6. The yields of the reactions are quantitative in all cases and the products do not require further purification. A series of 5-arylazo...

In the crystal structure of the title compound, C23H19N5O3·0.58C2H6OS·0.42C2H3N, prepared by the azo coupling of the 4-nitro-phenyl-diazo-nium salt with 3a-(p-tol-yl)-2,3,3a,4-tetra-hydro-1H-benzo[d]pyrrolo-[1,2-a]imidazol-1-one, the azo mol-ecules are linked by N-H⋯O hydrogen bonds into chains along the a-axis direction, and by the π-π inter-action into [101] chains. The dimethyl sulfoxide and...

Isothiazolopyridines, pyridothiazines and pyridothiazepines are important compounds that possess valuable biological activities. This paper reports on the synthesis of these compounds using both conventional chemical methods and modern microwave techniques. 3-Bromo-6-hydroxy-4-methyl-2-thioxo-2,3-dihydropyridine-3-carboxamide, 5-arylazo-6-hydroxy-4-methyl-2-thioxo-1,2-dihydropyridine-3-carboxam...

The catalytic asymmetric cyclopropanation of a C]C double bond provides efficient access to optically active cyclopropane derivatives that are essential motifs in natural products and valuable building blocks for various transformations. Chiral transition-metal-catalyzed carbene transfer, such as that using Cu(I)-, Rh(II)-, Ru(II)-, and Co(II)-complexes with diazo compounds, permits such cylcop...

THE pigments present in the blood-serum in jaundice were first differentiated by van den Bergh, who found that, whereas all icteric sera coupled with diazobenzene-p-sulphonic acid (Ehrlich's diazo-reagent) in the presence of alcohol, only certain of these sera would couple in simple aqueous solution. These diazo-reactions van den Bergh termed "indirect" and "direct" respectively, and it is now ...

Azaserine, a natural product containing diazo group, exhibits anticancer activity. In this study, we investigated the biosynthetic pathway of azaserine. The putative azaserine gene ( azs ) cluster, which contains...

In the title compound, C(6)H(9)N(3)O(3), the 3-diazo-2-oxopropan-amide section of the mol-ecule is nearly planar, with a maximum deviation of 0.025 (1) Å from the mean plane of its constituent atoms. The diazo C=N=N angle is 178.0 (3)°. In the crystal, pairs of inter-molecular O-H⋯O and N-H⋯O hydrogen bonds link the mol-ecules into infinite double chains along the [100] direction. The double ch...

α,β-Unsaturated amidines can be synthesized in high yield by rhodium(II) carboxylate catalyzed 1,2-H shift following denitrogenation of α-diazo amidines. Using a large ligand and an electron-poor N-sulfonyl group results exclusive Z-selectivity excellent suppressing side reactions involving intramolecular oxygen transfer.