2,3-diazabicyclo[2.2.0]hex-2-ene

✍ Scribed by Eva A. Wildi; Barry K. Carpenter

• Publisher: Elsevier Science
• Year: 1978
• Tongue: French
• Weight: 184 KB
• Volume: 19
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)94802-6

✦ Synopsis

The diazabicyclo[2.2. n] alkenes e, n = l-4) have received considerable attention both for their spectral properties1 and for their thermal nitrogen extrusion reactions.

2 We now report the synthesis of the lowest, and presumably most strained, member of this series, 2,3-diazabicyclo-[2.2.O]hex-2-ene (2J. The reaction sequence employed in the preparation of z is outlined in Figure 1. Two feature of this synthesis warrant further discussion. Firstly, attempts to hydrolyze the bisurethane 3 under the usual conditions of potassium hydroxide in ethylene glycol at high temperature3 were unsuccessful, resulting in complete destruction of the molecule. Acid catalyzed hydrolysis was similarly unproductive. By contrast, we found that the medium employed by Gassman for the hydrolysis of amides4 effected clean hydrolytic cleavage of 3 at room temperature in three hours. Subsequent experiments have shown that the reagent is equally effective for the hydrolysis of other bisurethanes and may thus provide a convenient method for synthesizing acid-sensitive or thermally labile azo compounds.