The Nef Reaction on 9,10-Dihydro-(11-nitroethano)-anthracenes. A New Route to 9,10-Dihydro-(11-ketoethano)-anthracenes¹

Abstract

and azoisobutyronitrile (3.24 g.) were refluxed in 30 ml. of benzene for 8 hr. under nitrogen. The benzene and tetramethylsuccinonitrile were removed by steam distillation. The yellow residue was dissolved in benzene, dried, and the solvent was removed by heating on the steam-bath for 1 hr. in vacuo.The yellow glass which resulted (1.82 g.) did not form a crystalline picrate. Seeding of 187 mg. of this material in benzene-absolute ethanol with a crystal of dihydro-bis-(cyanopropyl)-benzpyrene (X, m.p. 222-224°) yielded 10 mg. of white crystals, m.p. 220-224°. Dehydrogenation of the yellow glass with sulfur at 215°a nd with 10% palladium-charcoal at 315°yielded benzpyrene as the sole identifiable product. Dehydrogenation with chloranil in boiling xylene for 47 hr. yielded an impure sample of X.Dehydrogenation of Dihydro-bis-(cyanopropyl)-benzpyrene (X).-The bis-compound X (29 mg., m.p. 208-220°) was mixed with 4 mg. of 10% palladium-charcoal and heated under nitrogen at 315°for 1 hr. in a sublimation apparatus. The sublimate was rinsed into the apparatus with benzene, the benzene was removed on the steam-bath, and the material was heated at 315°for 1 hr. more.The mixture was dissolved in benzene, filtered and was concentrated on the steam-bath under nitrogen. The residue could not be recrystallized from benzene-hexane; it was therefore sublimed at 140-165°( 0.1 mm.), and the yellow sublimate (9.2 mg.) was recrvstallized from benzene-hexane. The yellow crystals obtained (4.5 mg.) melted at 176-178°and gave no depression on mixed m.p. with authentic benzpyrene.

Photo Retro-Diels–Alder Reactions

“…In this work, a variety of normal-electron-demand DA adducts were prepared, − and the electronic effects of the diene and dienophile components on the PrDA reactivity were studied (Scheme ). Aromatic DA adducts were used because they can efficiently absorb at 254 nm, which was the wavelength chosen for measuring the quantum yields of these photoreactions.…”

“…Acetonitrile was distilled over molecular sieve under nitrogen before being used. TCNE/anthracene ( 1 ), acrylonitrile/anthracene ( 8 ), TCNE/phencyclone ( 12 ) tetramethyl-2,6-diaminoanthracene, 2,6-dimethoxyanthracene, , and 2,6-dimethylanthracene were synthesized following literature procedures.…”

The Structures of Haemanthamine and Crinamine1

“…A similar explanation has been given for the anomalous spectra of several derivatives of 9,10-dihydro-9,10-ethano-ll-ketoanthracene (XXVII) in which a similar situation exists. 46 These anomalous bands at 313 and 324 µ in V and VI undergo a hypsochromic shift of 7 µ and an increase in extinction coefficient in acid solution, which may be attributed to an increase in the energy required for polarization of the carbonyl group adjacent to the positively charged nitrogen atom. XXVII Rielar and Mr. Harry Mueller for the isolation of the pure alkaloids.…”

Photo‐Diels‐Alder Reactions of Anthracene

“…140-142 4.9-5.1 (m) 5.34 (3.5) 6.35; 6.16 (3.5) 8.77 (7.2) 5.38 (3.5) 6.34; 6.19 (3.5) 8.96 ( Also on selective irradiation of ( I ) in styrene (8), with addition of some hydroquinone to prevent spontaneous polymerization, the photo-Diels-Alder reaction favorably competes with the copolymerization, although the reaction is slowed down by formation of a by-product (shoulder at h= 333 nm) that regenerates (1) at 25°C. (9) can be distilled off from copolymers of ( I ) and (8) in a vacuum: reproducible yield…”

“…[ 3]), and the electron-richer p-vinylanisole can be used instead of (8) [formation of (9) with a p-methoxyphenyl group in place of C,H, : m. p. 128 "C]. (2.0) 9.19 (6.0)…”