Synthesis of Novel Bis(benzoxazole) Derivatives by Tandem Claisen Rearrangement and Their Fluorescence Behavior

✍ Scribed by Emiko Koyama; Gang Yang; Seiji Tsuzuki; Kazuhisa Hiratani

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 186 KB
• Volume: 2002
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/1099-0690(200206)2002:12<1996::aid-ejoc1996>3.0.co;2-q

✦ Synopsis

Novel bis(benzoxazole) derivatives were easily synthesized from isobutenyl bis(amide-ether)s by tandem Claisen rearrangement and subsequent intramolecular cyclization of the amide-phenol intermediates. The yields of the bis(benzoxazole)s depended on whether the reaction was carried out with or without solvent, as well as on the substituents on the aryl group and the carbonyl group. The solvent effect was dramatic. No significant difference in the overall reaction rate constant with variation of the substituents on the car- [ ‡