Adhikary P F, Das S K, Hess B A
J Med Chem. 1976 Nov;19(11):1352-4. doi: 10.1021/jm00233a022.
The synthesis of pyridino[1,2-a]imidazo[5,4-b]indole (1) and thiazolo[3,2-a-a]imidazo[5,4-b-a]indole (2) has been achieved by phosphite reduction of 3-nitroso-6-phenylimidazo[1,2-a]pyridine and 5-nitroso-6-phenylimidazo[2,1-bb]thiazole. Compound 1 has shown strong antihypertensive activity in spontaneously hypertensive rats while compound 2 showed similar bioactivity both in spontaneously hypertensive rats and in normotensive dogs. A tricyclic amino derivative, 3-amino-2-phenylimidazo[1,2-a]pyridine, which has structural resemblance to compound 1, showed no hypotensive activity.
通过亚磷酸酯还原3-亚硝基-6-苯基咪唑并[1,2-a]吡啶和5-亚硝基-6-苯基咪唑并[2,1-bb]噻唑实现了吡啶并[1,2-a]咪唑并[5,4-b]吲哚（1）和噻唑并[3,2-a-a]咪唑并[5,4-b-a]吲哚（2）的合成。化合物1在自发性高血压大鼠中显示出强烈的降压活性，而化合物2在自发性高血压大鼠和正常血压犬中均显示出类似的生物活性。一种与化合物1结构相似的三环氨基衍生物3-氨基-2-苯基咪唑并[1,2-a]吡啶没有降压活性。
