1220122-29-1Relevant articles and documents
Efficient synthesis of new tetracyclic benzofuro[3,2-d]-imidazo[1,2-a]pyrimidine-2,5-(1H,3H)-diones
Hu, Yanggen,Liu, Min,Ding, Mingwu
experimental part, p. 309 - 312 (2010/10/19)
The aza-Wittig reaction of iminophosphorane (1) with aromaic isocyanates gave carbodiimides (2), which were allowed to react further with α-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.