with aromaic isocyanates gave carbodiimides (2), which were allowed to react further with (‐amino ester in the presence of a catalytic amount of sodium ethoxide to give selectively new tetracyclic benzofuro[3,2‐d]imidazo[1,2‐a]pyrimidine‐2,5‐(1H,3H)‐diones (5) in good yields. X‐ray structure analysis of 5i verified the proposed structure and the reaction selectivity.
亚
氨基
磷烷(1)与芳香族
异氰酸酯的氮杂-维蒂希反应生成碳二
亚胺(2),使其在催化量的
乙醇钠存在下与( -
氨基酯)进一步反应,从而选择性地生成新的四环
苯并呋喃[3,2]。 - d ]
咪唑并[1,2一]
嘧啶-2,5-(1 ħ,3 ħ) -二酮(5。以良好产率)的X-射线结构分析5I验证所提出的结构和反应选择性。