Journal of Chemical Research

New imidazo[2,1-b]-1,3,5-thiadiazines and 1,2,4-triazino[3,2,-b]-1,3,5-thiadiazines, which have been prepared in good yields under Mannich reaction conditions. The antibacterial activity of some compounds have been evaluated.

Benzylation of p-dialkoxybenzenes can be achieved through the use of modified montmorillonite K10 clay. For the first time, syntheses of nitro-diarylmethanes were obtained by Friedel-Crafts alkylation with good yields. In the case of p-methoxymethyl phenyl ether and phenyl ester, selectivity favoring Fries rearrangement over benzylation is reported.

Some new 6-aryl-7-cyano-1,5-diazatricyclo[7,4,1^1,9,0^5,14]tetradeca-6,9-dien-8-ones (4a–c) and 6-aryl-7-cyano-1,5-diazatricyclo[7,1,2^1,9,0^5,12]dodeca-6,9-dien-8-ones (5a–c) have been prepared in moderate to good yields by reacting ethyl (E)- and (Z)-3-aryl-3-chloro-2-cyanopropenoates (1a–c) with DBU (1,8-diazabicyclo[5,4,0]undec-7-ene) and DBN (1,5-diazabicyclo[4,3,0]non-5-ene).

Tert-butyl esters 3 and 3-cyanopyrrolidines 6 are prepared by phase-transfer-catalysed reactions of symmetrical 4,4′-disubstituted N-(benzylidene)benzylamines with tert-butyl cinnamate and α-phenylcinnamonitrile, respectively; similar reactions of mono-substitited N-(benzylidene)benzylamines afforded mixtures of compounds 3, respectively 6, and their regioisomers 3(A) and 6(A).

Various alkyl-substituted p-dimethoxybenzenes (ArH) react readily with nitric acid and sulfuric to form nitro-products (ArNO₂). When the nitric acid is used in excess, the nitro-product react via either nitration to dinitro-compound (Ar(NO₂)₂) or via oxidative demethylation to nitro-p-quinone (Q). As such, the competition between the nitration, polynitration and oxidative dealkylation is effectively modulated by the added nitric acid and the alkyl-substituted p-dimethoxybenzenes.

The product distribution of sodium bismuthate mediated oxidation of several hydrofluorenes was found to depend on the structure of the starting materials and reaction conditions.

The oxidation of benzyl alcohol by dichromate and seven chromium(VI) complexes in aqueous acetic acid in the presence of perchloric acid is first order each in the oxidants, the alcohol and the mineral acid. The oxidation conforms to the isokinetic and Exner relationships and follows a common mechanism.

Mixed-valent salts Ba₃(MnO₄)₄ and BaK(MnO₄)₂ are indicated by maximal 1:1 mixed-component conductivities, as governed by Marcus reorganisation energies.

α, β-unsaturated tellurolesters have been prepared in good yield by the reaction of ArTeI with acylzirconocene chlorides.

(±)Trans-2-aminocyclohexanesulfonic acid and (±)trans-2-aminocyclopentanesulfonic acid were prepared respectively from cyclohexene and cyclopentene by sulfur monochloride addition, followed by oxidation to 2-chlorosulfonic acid and substitution of chlorine.

Montmorillonite K-10 catalyses the conversion of oxiranes to the corresponding thiiranes in the presence of thiourea efficiently and the yields obtained are excellent.

The reaction of β-cyanoester 1 with a two-fold excess of the lithium salt of homoveratrylamine in THF at 0 °C to room temperature affords the imidosuccinimide 3, which undergoes derivation to the succinimide monooxime 4 by treatment with m-chloroperoxybenzoic acid.

A new and effecient method for cleavage of oximes has been achieved by a simple reaction of an oxime with clayfen in dichloromethane and under microwave irradiation in solventless system.

A facile and efficient method for the selective deprotection of 1,1-diacetates to the corresponding aldehydes in the presence of TiO₂/SO₄^2- solid superacid in excellent yield is described.

A facile stereoselective synthetic procedure to (+)-ferruginyl methyl ether and (+)-sugiyl methyl ether has been developed with high stereoselectivity and overall yield.

Aldol condensation of amide enolates with imines affords β-amino acid dialkylamides in both high yields and excellent threo diastereoselectivity; electronic factors seem to be of great importance for successful interaction.

9-Halogenoacridines undergo Suzuki cross-coupling reactions with a range of arylboronic and thienyl-3-boronic acids to yield substituted 9-arylacridines and 9-(thien-3-yl)acridines.

The reaction of 3-t-butyl-2-hydroxy-5-methoxybenzaldehyde 6 with acetylacetone resulted in the formation of an unusual product, 1-[8-(t-butyl)-6-methoxy-2H-chromem-2-ylidene] acetone 4.

A new olefination catalysed by a base (KOBu^t) and its application to the stereoselective synthesis of substituted (E)-α-cyano and (E)-α-ethoxycarbonyl vinylphosphonates is described.

2,2,2-Trifluoroethylarenes were obtained in good yield from the addition of KF to 2′,2′-difluorostyrenes in the presence of crown ether. A linear regression line obtained from correlation between log(reaction rate) and Hammett constants with slope of +4.28 suggested that this addition process is very sensitive to the substituents on the phenyl ring.

A solvent-free method for the efficient preparation of symmetrically trisubstituted aryl or alkyl isocyanurates from isocyanates catalysed by sodium or potassium piperidinedithiocarbamate or the readily available sodium or potassium nitrite under conventional or microwave heating is described.

A simple and efficient method for one step oxidative decarboxylation of some aromatic carboxylic acids, using potassium permanganate in non-aqueous media is described.