The crystal structure of 3′-methoxy-5-phenyl-5,10-dihydrophenarsazine,C19H16AsNO

The crystal structure of 3′-methoxy-5-phenyl-5,10-dihydrophenarsazine, C₁₉H₁₆AsNO has been determined by the single crystal x-ray diffraction method. The crystals are monoclinic with a = 15.305(6), b = 5.809(2), c = 17.595(6)Å, β = 92.92(2)°, V = 1562.3(1.0ų, space group P2,/n, Z = 4 and d_calc = 1.485g cm⁻³. An automatic diffractometer with graphite monochromatized MoKα radiation was used to obtain 1480 observed reflection with I > 3σ(I) at 2θ < 50°. Final R = 0.040 and wR = 0.032. The tricyclic ring is folded with the central ring in a flattened boat conformation. The folding angle between the least-squares planes of the two benzo rings is 164.6(2)°. The 3′-methoxyphenyl group is in a boat-axial conformation with respect to the central ring.     

Nucleophilic reactions of l-methyl-2-methoxy-2-phenyl-3-oxo-2,3-dihydroindole

The title compound (1) was prepared via methylene blue (MB)-sensitized photooxy-genation of l-methyl-2-phenylindole (2d) in methanol. Acid-catalyzed nucleophilic substitution of 1 with nucleophiles gave 1,2,2-trisubstituted 3-oxo-2,3-dihydroindoles (3–6). Reduction of 1 with lithium aluminum hydride, followed by acidic workup yielded 4d and 2d, whereas the same reduction reaction of 1, followed by neutral workup gave l-methyl-2-phenyl-3-hydroxy-2,3-dihydroindole (15), together with 3. The reaction pathways of nucleophilic substitution and reduction of 1 were discussed.     

5-Hydroxy-3-phenyl-5-vinyl-2-isoxazoline and 3-phenyl-5-vinylisoxazole: synthesis and reactivity

5-Hydroxy-3-phenyl-5-vinyl-2-isoxazoline has been synthesized by reacting benzonitrile oxide with the enolate ion of methyl vinyl ketone. From 5-hydroxy-5-vinyl-2-isoxazoline, 5-vinylisoxazole was then quantitatively obtained by dehydration-aromatization under acidic conditions. Similar results, though not quantitative, were also found by treatment in 2-propanol under basic conditions (i-PrOH/H₂O, Na₂CO₃, reflux). In contrast to 2-propanol, reactions performed in methanol (and, in part, those carried out in ethanol) revealed a more complex behaviour, the nucleophilic addition of ROH onto the vinyl group being mainly observed. Nucleophilic addition was also found with alkyllithiums. The mechanism of the nucleophilic addition is discussed. Epoxidation and further reaction with benzonitrile oxide of both 3-hydroxy-5-phenyl-5-vinyl-2-isoxazoline and 3-phenyl-5-vinylisoxazole are also described.     

Formylation of 2-phenyl- and 3-phenyl-5-hydroxybenzofuran derivatives

The Vilsmeier formylation of 2-phenyl- and 3-phenyl-5-hydroxybenzofuran derivatives was studied. It is shown that 2-phenyl-5-methoxybenzofuran is formylated in the 4 position, whereas 3-phenyl-5-methoxybenzofuran is formylated in the 2 position.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1023–1024, August, 1976.     

Nucleophilic reactions of 1-methyl-2-methoxy-2-phenyl-3-oxo-2,3-dihydroindole

The title compound (1) was prepared via methylene blue (MB)-sensitized photooxy-genation of l-methyl-2-phenylindole (2d) in methanol. Acid-catalyzed nucleophilic substitution of 1 with nucleophiles gave 1,2,2-trisubstituted 3-oxo-2,3-dihydroindoles (3-6). Reduction of 1 with lithium aluminum hydride, followed by acidic workup yielded 4d and 2d, whereas the same reduction reaction of 1, followed by neutral workup gave l-methyl-2-phenyl-3-hydroxy-2,3-dihydroindole (15), together with 3. The reaction pathways of nucleophilic substitution and reduction of 1 were discussed.     

Cycloaddition to aminomethylene derivatives of 1-phenyl-3-methylpyrazole-5-thione and 1-phenyl-3-methylpyrazole-5-selenone

Addition products — anhydrides of 1-phenyl-3-methyl-4-alkylamino-4,5,6-tetrahydrothio(seleno)pyrano-3, 2-pyrazole-5,6-dicarboxylic acids — were obtained by cycloaddition of maleic anhydride to aminomethylene derivatives of 1-phenyl-3-methylpyrazole-5-thione and 1-phenyl-3-methylpyrazole-5-selenone, while anhydrides of the corresponding dihydrothio(seleno)pyranopyrazoledicarboxylic acids were obtained by splitting out of an amine. The oxygen-containing analog does not undergo cycloaddition. An oxanol dye is formed from 1-phenyl-3-methyl-4-dimethylaminomethylene-5-pyrazolone, whereas the corresponding acyl derivative was isolated from the monomethyl derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 527–529, April, 1979.     

The solid-state michael addition of 3-methyl-1-phenyl-5-pyrazolone

A novel solid-state Michael addition between pyrazolone 1 and 4-arylidenepyrazolones 2 at ambient temperature produced Michael adducts, 4,4′-arylidenebis(3-methyl-1-phenyl-5-pyrazolones) 3. Pyrazolones 3 formed salts 4 with Cu²⁺ in solution, indicating the enolic structure of the pyrazolone rings. The reactivity of 2 with 1 is discussed in terms of the electronic and steric effects of the substituent on the arylidene group of compounds 2 . Pyrazolone 1 also underwent the solid state Michael addition reaction with maleimide at 100° to give the adducts 7,8 and 9 .     

Molecular and crystal structure of 2-amino-1,3-dicyano-4-methoxy-4-phenyl-3-benzoylmethylcyclopentene

M. V. Lomonosov Moscow State University, Chemical Department. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 5, pp. 971–976, September–October, 1996.     

Spatial structure of 2-benzoyl-3-methoxy-5-methylisoxazolidine

The nuclear Overhauser effect and x-ray diffraction analysis have been employed to determine the spatial structure of the diastereoisomeric 2-benzoyl-3-methoxy-5-methylisoxazolidines. It has been found that the predominant isomer in the reaction mixture has the cis-configuration.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1255–1260, September 1989.