The bromine atom in diethyl 2-acetamido-6-bromoazulene-1, 3-dicarboxylate (I) is as reactive toward the anionoid reagents as in diethyl 6-bromoazulene-1, 3-dicarboxylate. Twentyseven 6-substituted azulene derivatives have been synthesized from I by the nucleophilic substitution reaction. On one of them, diethyl 2-acetamido-6-diethylaminoazulene-1, 3-dicarboxylate, the removal of the 2-acetamido group has been carried out, giving diethyl 6-diethylaminoazulene-1, 3-dicarboxylate.
                                    2-acetamido-6-bromoazulene-1, 3-dicarboxylate (I) 中的
溴原子与 6-bromoazulene-1, 3-dicarboxylate 中的
溴原子一样对阴离子试剂具有活性。由 I 通过亲核取代反应合成了 27 种 6-取代的氮杂
环戊烯衍
生物。在其中一种 2-乙酰
氨基-6-二乙
氨基唑烯-1,3-二
甲酸二
乙酯中,2-乙酰
氨基被去除,得到 6-二乙
氨基唑烯-1,3-二
甲酸二
乙酯。