Abstract
Ring expansion reaction and dehydrochlorination reaction of substituted-2-chloromethyl-3-aryl-4-oxo-1, 2, 3, 4-tetrahydroquinazolines (2a-g) were investigated. The required starting materials 2a-g were prepared from the corresponding 4 (3H) quinazolines (1a-g) by NaBH4 reduction in excellent yields. 2a-f were easily converted to dehydrochlorination products 3a-f in CHCl3 at room temperature. On the other hand, treatments of 2a-f with EtONa in EtOH afforded ring expansion products 4a-f. The mechanism of the ring expansion reaction was proved by the isolation of an intermediate, azirinoquinazoline (7). The investigation was extended to the reactions of azirinoquinazoline (7) with nucleophiles. The reactions with NaBH4, MeOH, AcOH, PhSH, and EtSH proceeded analogously to give benzodiazepines (8, 9, 10, 11, and 12).
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
