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Dibromoisocyanuric acid proves to be a more efficient reagent for the dibromination of the title pyrazole derivatives than NBS.

The advantage of the presented one-pot method is primarily a simple work-up procedure without isolation and purification of the intermediate 5-amino-1,3-diphenyl-pyrazole.

A new spirocyclization was developed for the synthesis of 1,7-dioxaspiro[5.5]undecanes and 1-oxa-7-thiaspiro[5.5]undecanes by reaction of exo -glycal with aryl alcohols or thiophenols in the presence of Lewis acid BF 3 ·OEt 2 . The reaction proceeded through tandem Ferrier rearrangement, glycosylation, and Friedel–Crafts alkylation to provide the corresponding products in good to excellent yields.

Cyclohexanone was employed as a coreactant in the liquid-phase oxidation of cyclohexane using glacial acetic acid as a solvent and CoAPO-5 as a catalyst at 105-135°C and 10 kg/cm2. Addition of cyclohexanone increases the rate of cyclohexane oxidation and selectivity to adipic acid. When the cyclohexanone concentration increases, the rate will increase at 115°C but decrease at 135°C, while the cyclohexanone concentration has no obvious effect on the rate at 125°C. The apparent activation energy for cyclohexane oxidation in the cooxidation system is lower than that of cyclohexane oxidation in the system without the addition of cyclohexanone. An increase of catalyst loading in the cooxidation system, though, increases the rate of cyclohexane oxidation but decreases the yield of adipic acid. Use of carboxylic acid, except formic acid, as the solvent is necessary for the oxidation of cyclohexane. Of acetic acid, propionic acid, butyric acid and n-pentanic acid, the use of propionic acid results in the highest reaction rate when the temperature is below 135°C, while these four carboxylic acids give almost the same conversion after 2 h at 135°C.

A new safe and convenient transformation has been developed. In the presence of cesium formate in dry MeOH solution, α-haloketones underwent direct conversion reaction to afford α-hydroxyketone in excellent yields. Furthermore, this methodology can be extended and applied in 2-chloro-N-(1,3-diphenyl-1H-pyrazol-5-yl)acetamide, 2-chloro-N-(2,6-dimethylphen-yl)acetamide, 1-(bromomethylsulfonyl)benzene, and N-(bromomethyl)phthalimide to give the corresponding products in moderate to excellent yields.

β-Enamino ketones were successfully synthesized in good to excellent yields by reaction of hex-1-en-3-uloses with amines. After hydrogenation on palladium catalyst, β-enamino ketones effectively underwent hydrodeamination and were converted to the corresponding 1,2-dideoxy- d -threo-3-hexulose derivatives in 89–95% yields.

Novel 4-amino-2-phenylquinoline derivatives were synthesized by reacting various 4-chloro-2-arylquinoline compounds having activated chloro group with the corresponding amide solvents at reflux for overnight. The activity of amination by the amide solvents depended on the competition between the steric and electronic effect of the N -substituents on the amino group. Their activities were shown as N , N -dimethylformamide> N , N -diethylformamide> N -methylformamide>formamide> N , N -dimethylacetamide> N , N -dimethylpropionamide. The yields for the amination products seemed proportional to the ease of the dissociation of the amides.

Sodium bis(trimethylsilyl)amide was first used as the desulfurizing agent for the conversion of isothiocyanates to cyanamides in a ‘one-flask’ reaction.