Photochemical addition of N-acyldiphenylmethyleneimine to cyclic and acyclic olefins

✍ Scribed by Naoki Toshima; Shuichiro Asao; Kanako Takada; Hidefumi Hirai

• Publisher: Elsevier Science
• Year: 1970
• Tongue: French
• Weight: 213 KB
• Volume: 11
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)96955-7

✦ Synopsis

Recently, it has been reported that a 2-aza-enone compound, aza-analog of a,S-unsaturated ketone, is easily reduced on irradiation with ultraviolet light (l-4). However, there is no record on the photochemical addition reaction of the 2-aza-enone to olefin. We wish to report the photochemical addition reaction of N-acetyldiphenylmethyleneimine (I) to several olefins. A solution of I (5.7 mmol) in cyclohexene (54 mmol) was irradiated for 100 hr with a 500W high pressure mercury lamp under a nitrogen atmosphere, which resulted in a conversion of I by 20%. Chromatography on silica-gel of the evaporated reaction mixture gave one photoproduct in 75% yield based on the consumed imine. The elemental analysis and the molecular weight measurement of the isolated product, mp 181.0Oc, were consistent with those of the 1:l adduct of I with cyclohexene (Found: C, 82.37; H, 7.32; N, 4.61; mol wt, 285 (5). Calcd for Ce,He,ON: C, 82.58; H, 7.59; N, 4.59; mol wt, 305). The UV spectrum (5) showed the existence of the separated phenyl group [liigH 253.6(logf=2.71), 259.4(.2.75), 265.0(2.67), and 270.5 nm(2.47)] and the IR spectrum (5) had the same kind of bands(3290, 1660, and 1540 cm-'), Q., amide type absorption bands, as N-diphenylmethylacetamide, a photoreduction product of I (1,2). The olefin test (KMnO, test and Brs test) indicated the existence of C=C bond. The NMR spectrum (5) had bands at b 7.00-7.95 (lOH, singlet, phenyl protons), 6.32 (lH, broad singlet, NH proton), 5.47 (2H, broad singlet, olefin protons), 3.65-4.00 (IH, broad multiplet, methine proton), and 0.85-2.08 (9H, complex multiplet, aliphatic protons). On the basis of these informations, the product was identified with N-(diphenylcyclohex-2t-enylmethyl)acetamide (II).