5,7-Diaryl-1,3-dimethyl-2,4-dioxo-1H,2H,3H,4H-pyrano[4,3-d]pyrimidinium bromides react with malonodinitrile to form 1,3-dimethyl- 2,4-dioxo-1H,2H,3H,4H-quinazolines, whereas their reaction with nitromethane gives dihydro-1,3-dimethyl-5-nitromethyl-2H- pyrano[4,3-d]pyrimidine-2,4(3H)-diones, the ...

The 1,3-dimethyl-2,4-dioxo-1H,2H,3H,4H-pyrano[4,3-d]pyrimidinium cation has been prepared by means of acid-catalyzed cyclization of 1,3-dimethyl-6-(2-dimethylaminoethenyl)pyrimidine-2,4(1H,3H)-dione in a chloroform–trifluoroacetic acid solution, and its reactivity towards N-nucleophiles has bee...

By using a secondary amine, e g. piperazine, a Mannich base polymer, having similar structure to the traditional polybenzoxazine, is synthesized. Unlike all the reported polybenzoxazines that are colored, the white polymer shows good thermal property that is close to the degradation temperature ...

The vibration spectrum and FAB mass spectrum of (±)-1-[3-(2-methoxyphenoxy)-2-hydroxypropyl]-4-[(2,6-dimethylphenyl)aminocarbonylmethyl]piperazine dihydrochloride salt was studied. By comparing with the spectra of free base, different bands of IR were found in the NH+ stretching, the NH+ defoma...

(±)-1-[3-(2-Methoxyphenoxy)-2-hydroxypropyl]-4-[(2,6-dimethylphenyl)aminocarbonylmethyl]piperazine dihydrochloride salt was studied spectroscopically. Complete NMR assignments for dihydrochloride salt were made using DEPT, H–H COSY, as well as HMQC and HMBC heteronuclear correlation techniques.

Heat capacities, enthalpies of phase transitions, and derived thermodynamic properties over the temperature range 5

Publisher SummaryThis chapter provides information on three-membered ring systems. The chemistry of three-membered rings continues to be as exciting, owing to the enormous synthetic utility of these compounds. The chapter presents the discussion from a synthetic chemist's point of view, wit...

Reaction of α,β-dichloroacrylonitrile with arylsulfinate salts in refluxing ethanol gave high yields of arylsulfonylacetonitriles. A proposed intermediate, α-chloro-β-p-tolylsulfonylacrylonitrile can be isolated and can be converted to p-tolylsulfonylacetonitrile under the conditions of the ...

A new and highly efficient method for the synthesis of 4-(benzimidazol-2-yl)quinolin-2(1H)-ones via the rearrangement of spiroquinoxalinones in moderate-to-excellent yields has been developed. The rearrangement represents a facile approach to medicinally important biheterocyclic compounds. Compa...

Background/aimDerivatives of thiazolidinones have attracted interest in recent years because it exhibits broad spectrum of biological activities like anticonvulsant, analgesic, anti-inflammatory. Thus we report the facile synthesis, characterization and biological evaluation of novel 1-[2 (subst...

Based on the roles of Raf1 and JNK1 in hepatocarcinoma development, scaffold-based drug design was employed to produce a series of compounds, which subsequently were synthesized and explored as potential dual inhibitors Raf1 and JNK1 kinases for anti-tumor treatment. The compound 1-(3-chloro-4-(...

1, 5-Bis(trimethylsiloxy)-1, 5-dimethoxy-1, 4-pentadienes (7) can be prepared in good yield by silylation of the dianions of dimethyl glutarates (8). On treatment with titanium tetrachloride, 7 cyclise stereoselectively to dimethyl trans-cyclopropane-1, 2-dicarboxylates 10. Reaction of 7 with ac...

The regioselectivity of the reaction between benzaldehyde and the silylketene acetal prepared from trimethylsilylsenecioate is studied as a function of the catalyst used. CsF leads exclusively to the “branched” product whereas TiCl4 gives the required “linear” hydroxy acid.

o-Tributylstannylmethyl benzaldehyde reacts with Zn in the presence of TMSCl and 2,6 lutidine at room temperature to give α-trimethylsiloxy-o-quinodimethane, which is trapped with dienophiles to afford cycloadducts in good to high yields.

The preparations of 4-trimethylsilyl-2-butenoate trimethylsilyl ester and 1,1- bis(trimethylsiloxy)-1,3-butadiene are described. The latter silyl derivative reacts with benzaldehyde in the presence of ZnBr2 in THF to give exclusively γ-substituted product (E configuration) in high yield. The fl...

Kidney acetone powders (KAP) from beef, dog, hog, rat, and sheep have been evaluated for resolving N-acetyl-dl-homophenylalanine. We also propose a simple protocol for the preparation of both enantiomers of homophenylalanine by enzymatic resolution using mammalian KAP. The beef kidney afforded t...

Two series of halogenated 1-benzyl-7-chloro-6-hydroxy-tetrahydroisoquinolines were prepared to explore the influence of each series on the affinity for dopamine receptors. All the compounds displayed a high affinity for D1-like and/or D2-like dopamine receptors in striatal membranes, although th...

Polymorphism has attracted increasing attentions due to its particular importance in the field of pharmaceutical industry, especially the studies on the conformations of different crystal structures. In this work, the relationship between crystalline forms and conformations of benidipine hydroch...

Monoacylglycerol lipase (MAGL) is a major serine hydrolase that hydrolyses 2-arachidonoylglycerol (2-AG) into arachidonic acid (AA) and glycerol in the brain. Because 2-AG and AA are endogenous biologically active ligands in the brain, the inhibition of MAGL is an attractive therapeutic target f...

New diphenyltin(IV) complexes of empirical formula, [Sn(C6H5)2(NS)Cl] (NS = anionic forms of the acetone Schiff bases of S-methyl or S-benzyldithiocarbazate) have been prepared and characterized by IR, NMR and Mössbauer spectroscopic techniques. The crystal and molecular structures of the aceton...