Viehe's Salt in a Novel One Pot Synthesis of Azolo[1,2-a]Pyrimidines

We have developed a practical procedure for the synthesis of polyfunctional azolo[1,5- a]pyrimidines via the reactive species generated in situ from N-substituted lactams and Viehe's salt. The described protocol allowed for the introduction of three elements of diversity into the targeted molecules, including substituents originating from the i) nucleophile input, ii) lactam ring and iii) nucleophilic aromatic displacement (SNAr) of the NMe2 group with amines. A short reaction sequence, good yields of title compounds (55-81%), as well as their ready isolation, and purification are the distinct advantages of the reported protocol.