An efficient one-pot condensation for the synthesis of 1,8-dioxo-octahydroxanthene is  achieved through a condensation of aryl aldehydes and 5,5-dimethyl-1,3-cyclohexandione in the presence of  NBS. This method enjoys several advantages such as low cost, simple work up procedure and safe reaction condition. In addition, water was chosen as a green solvent.

Reaction between aromatic aldehydes and 3–methyl-1-phenyl-2-pyrazoline-5-one catalyzed by nano-SiO2/HClO4 in water under reflux provided a simple and efficient route for the synthesis of 4-((5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)(aryl)methyl)-3-methyl-1-phenyl-1H-pyrazol-5-ol derivatives in high yields.

4-(acetoacetamido) arsanilic acid (II), which was then condensed with aryl aldehydes. The resulting product on reaction with hydrazine hydrate and hydroxyl amine hydrochloride yielded Pyrazolines (IV) and Isoxazolines (V), respectively. The antimicrobial activity of compounds against a number of microorganisms was evaluated. Some of these compounds showed significant antimicrobial activity

Silica sodium carbonate (SSC) has been used as a valuable silica-supported catalyst for the preparation of a range of known and novel pyrano coumarins via the three-component reactions of aryl aldehydes, active methylene compound (malononitrile or ethyl cyanoacetate), and hydroxycoumarin (5,7-dihydroxy-4-substituted coumarins or 4-hydroxycoumarin). The heterogeneous catalyst showed much the sam...

Reaction between aromatic aldehydes and 3–methyl-1-phenyl-2-pyrazoline-5-one catalyzed by nano-SiO2/HClO4 in water under reflux provided a simple and efficient route for the synthesis of 4-((5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)(aryl)methyl)-3-methyl-1-phenyl-1H-pyrazol-5-ol derivatives in high yields.

Zinc chloride silica gel-supported was found to be an efficient, inexpensive catalyst for the synthesis of 1,8-dioxodecahydroacridines via one-pot three-component condensation of aryl aldehydes, dimedone, andammonium acetate in high yields. The described novel synthetic method propose several advantages of safety, mild condition, short reaction times, high yields, simplicityand easy workup comp...

Some 5-aryl-2-mercapto-1,3,4-oxadiazole (I) reacted with maleic anhydride, maleic acid and p-benzoquinone affording 2-(5-aryl-1,3,4-oxadiazol-2-ylthio)succinic anhydrides (II), 2-(5-aryl-1,3,4-oxadiazol-2-ylthio)succinic acids (III) and 2-(2,5-dihydroxyphenylthio)-5-aryl-l,3,4-oxadiazoles (IV), respectively. Treatment of 2-methylthio-5-phenyl-l,3-oxadiazole (V) with amines gives 2-[(alkyl or ar...

The microwave assisted and solvent free synthesis of title compounds is described in this protocol. Ten new aryl imidazoles, which are incorporated with the chemotherapeutic pharmacophores, have been synthesized by adopting one pot multicomponent reaction. First, primary aromatic or heteryl amine has been condensed with aryl or heteryl aldehydes to afford corresponding Schiff base. The Schiff b...

The desired fused ring system 3-(3-chlorophenyl)-6-aryl-5,6-dihydro[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles 5a-j were synthesized by the reaction of 4-amino-5-(3-chlorophenyl)-4H-1,2,4-triazole-3-thiol and different aryl aldehydes in the presence of catalytic amount of p-TsOH in dry DMF, while 3-(3-chlorophenyl)-6-aryl-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines 7a-j were synthesized by using...

An extracellular lignin-degrading enzyme from the basidiomycete Phanerochaete chrysosporium Burdsall was purified to homogeneity by ion-exchange chromatography. The 42,000-dalton ligninase contains one protoheme IX per molecule. It catalyzes, nonstereospecifically, several oxidations in the alkyl side chains of lignin-related compounds: C(alpha)-C(beta) cleavage in lignin-related compounds of t...