Synthesis and Reactions of Diazoacetyl Chloride—Detection of Diazoketene

✍ Scribed by Prof. Dr. Hans Jürgen Bestmann; Dr. Fouad M. Soliman

• Book ID: 101550731
• Publisher: John Wiley and Sons
• Year: 1979
• Tongue: English
• Weight: 219 KB
• Volume: 18
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.197909471

✦ Synopsis

dene)ammonium perchlorate ( 8 ) I 5 I at -55 "C for 0.5 h this solution yields an intermediate fulvene which was not isolated. In order to effect cyclization of the fulvene to (3), the solvent is replaced by quinoline and the solution is heated at 170 "C for 12 h. After the usual work-up the crude product is purified by column chromatography over alumina with hexane. The desired compound (3) was obtained as colorless needles, m.p. 140°C (sealed capillary), in 35% yieldL6]. Its structural assignment is supported by its NMR spectrum [singlets at 6=2.53 (2H) and 7.29 (4H); AB2 pattern at 6=6.83 (A part) and 7.30 (B part) with JAB=8.7 Hz]. The UV absorption spectrum of ( 3) is very similar to those of (f)f3"l and (2)13b1 [Amax (cyclohexane) = 223 nm ( E = 28 800), 236 (27400), 246 (28200), 305 (14700)]. In the mass spectrum of (3) [m/e=216 (M', loo%), 215 (M'-H, 75%)] a peak due to loss of the bridged methano group, though very weak, was also observed [m/e= 202 (M' -CH2, 3%)]. These spectral findings indicate that, of the two valence isomers (3) and (34, only the metacyclophane structure (3) exists at room temperature.