Thermal Rearrangement of a Phthalazine to a Quinazoline
摘要:
This is the first reported thermal rearrangement reaction of a phthalazine to its structural isomer, a quinazoline. We have found that heating polyphenylated phthalazines 2b-d at 360 degrees C for 30 min gave the corresponding quinazolines in high yield. The less sterically crowded 1,4-bis(4-fluorophenyl)phthalazine (2a) gave only a low yield of quinazoline 3a. X-ray crystallographic analysis on 3b further confirmed our finding.