A one-pot synthesis of [6 + 61, [6 + 71, and [6 + 81 bicyclic guanidines based on a new method of dihydropyrimido annelation, which involves reaction of bia(iminophosphoranes) with aryl isocyanates or isothiocyanates is described. The method is also applicable for the preparation of chiral bicyclic guanidines. ... Compounds containing a cyclic guanidine moiety are of considerable interest because of a range of biological activities, as versatile very strong organic bases,' and ...
![2-methyl-11,13-dihydro-6H-quinazolino[2,3-b]quinazoline Structure](https://image.chemsrc.com/caspic/238/141236-15-9.png)
