M. T. Ismail

NONCONVENTIONAL FRIEDEL-CRAFTS CHEMISTRY II. ON THE CATALYTIC ACTION OF TRIFLIC ACID AND ALUMINIUM CHLORIDE ON SELECTED ARYL THIOESTERS

Abstract The catalytic action of triflic acid and/or aluminium chloride on seven selected aryl thioesters (1-7) gave in all cases aryl thiols, diaryl sulfides, diaryl disulfide, and thianthrene derivatives in addition to the corresponding aryl carboxylic acids. Thioester 5 gave thiochromanone derivatives in good yield under the same conditions. Plausible mechanisms were suggested to rationalize the obtained results.

MOLECULAR REARRANGEMENTS. VI. THERMOLYSIS OF α-(N-ARYL)BENZYL ARYL SULFIDES

Abstract In view of the significance of studying the effect of heat on organic compounds especially those containing nitrogen and/or sulfur, six substituted α-(N-aryl) benzyl aryl sulfides (4–9) were prepared and subjected to thermolysis at 200°C. Surveying of the reaction products showed the formation of amines, benzylidene amines, sulfides, disulfides, dibenzyl, stilbene, benzthiazole, benzimidazole, tetraphenyl thiophene as principle products in variable ratios according to the type of the starting sulfide. A mechanism involving the homolytic cleavage of the C[sbnd]S and the C[sbnd]N bond is suggested to rationalize the thermolysis products.

Nicotinic acid and nicotinamide electronic structural studies

Abstract After spectroscopic studies and SCF-CI calculations, it was concluded that nicotinic acid and nicotinamide have α-and β-forms. The β-conformer for nicotinic acid or nicotinamide has a higher π-electronic energy than the α-conformer by about 0.5 kcal mole−1. The electronic transition energies of the conformers show good agreement with the experimental data.

MODERN FRIEDEL-CRAFTS CHEMISTRY XVI. REACTION OF THIOPHENE WITH BIFUNCTIONAL MOLECULES UNDER DIFFERENT FRIEDEL-CRAFTS CATALYSTS: ATTEMPTED SYNTHESIS OF CYCLOPENTA[b] THIOPHENES AND DIHYDROBENZO[b] THIOPHENES

Abstract The reaction of thiophene (1) with 3-chloropropionyl chloride (2), 4-chlorobutyryl chloride (3), crotonyl chloride (4) and cinnamoyl chloride (5) under different Friedel-Crafts catalysts (A1C13/CH3NO2, FeCl3, and A1C13/CS2) was investigated. The cyclic products 4,5-dihydro-6H-4-methylcyclo-pental[b]-thiophen-6-one, 5,6-dihydrobenzo[b]thiophen-7(4H) one and 4-phenyl-6H-cyclopenta[b]thio-phen-6-one were formed. The different behaviors of compounds (2–5) towards thiophene were discussed.

Modern Friedel-Crafts chemistry. XIV: On the cyclization of selected aryl hydroxyalkyl sulfides

Abstract The feasibility of cycloalkylation reactions in the presence of Friedel–Crafts catalysts was demonstrated in a number of aryl hydroxyalkyl sulfides (1–5), and benzyl hydroxyalkyl sulfides (6–7). Treatment of compounds (1–7) with Friedel-Crafts catalysts gave diaryl disulfides, diaryl sulfides, arene thiols, chlorohydrins, aryl chloroalkyl sulfides, aryl alkenyl sulfides and cyclization products. It is noteworthy to mention that cyclization products were isolated only in cases where the hydroxyl group is linked to a tertiary carbon atom as in compounds 3 and 7. A suitable reaction pathway is suggested to rationalize the formation of the various reaction products.

Electvosynthesis of organic compounds. IV. Synthesis of some arylnitromethane compounds

Synthese par oxydation du nitrourethanure en presence de benzene, toluene, naphtalene, diphenylether, dimethoxy-1,4 benzene sur une electrode de platine dans le methanol

Organic Selenium Compounds. Part II. Synthesis and Antibacterial Activity of Some New Symmetrical Diarylselenides Containing Thiazolyl, Thiazolidin-4-Onyl, Azetidin-2-Onyl, Triazolin-1-YL and Glycyl Moieties

GRAPHICAL ABSTRACT Abstract 4,4′-Dimonochloroacetyl diphenylselenide (2) was prepared as a new precursor for the title studies by chloroacetylation of diphenylselenide (1). 2 interacts with thiourea to afford 4,4′-di(2″-aminothiazol-4″-yl)diphenylselenide (3). Condensation of 3 with aromatic aldehydes in the presence of a catalytic amount of dry piperidine furnished aldimines (4). Interaction of 4 with mercaptoacetic acid afforded 4,4′-di(2″-(2‴-substituted phenyl-3‴-thiazolo-4‴-thiazolidinon)-3‴-yl)diphenylselenides (6). Schiff bases 4 interact with mono chloroacetyl chloride in dry dioxane and triethylamine produced 4,4′-di(2″-(4‴-substituted phenyl-3‴-chloro-2‴-azetidinon-1‴-thiazolo)-1‴-yl)diphenylselenides (8). 1,3-Dipolar cyclonucleophilic addition of diazomethane to certain of 4 gave 4,4′-di(2″-(5‴-substituted phenyl-Δ2-1‴,2‴,3‴-triazoline thiazolo)-1‴-yl)diphenylselenides (10). 2 interacts with secondary heteroalicyclic amines to afford 4,4′-diglycyl diphenylselenides (11). The structures of the synthesized compounds are based on correct physical data, IR, 1H NMR, 13C NMR, and by chemical means. Some of the synthesized compounds were biologically tested.

Multiplicity and selectivity of cyclopent[a]acenaphthylenylidene

Abstract Cyclopent[a]acenaphthylenylidene 1 has been generated by photolysis from its precursor, the diazocompound 1a . Carbene 1 could be trapped in olefinic substrates to afford the spirocyclopropanes 8 – 12 . In addition triplet products of 1 such as 13 and dimer 14 were isolated. With trans-β-methylstyrene 1 undergoes a stereospecific addition. 2,3-Dimethylbutadiene and 1 reacted to the vinylspirocyclopropane 16 and 17 . Competition experiments of 1 with styrenes give a linear Hammett correlation with a ρ=0.38. Therefore, 1 is regarded as a nucleophilic singlet carbene in its additions to styrenes.