Synthesis and structure of functionalized podands containing 4,7-dihydrotetrazolo[1,5-а]pyrimidine ring. Differently substituted dihydropyrimidine podands

The reaction of 3-oxobutanoate-containing polyethers with benzaldehyde and 5-aminotetrazole in the presence of polyphosphoric acid was used to synthesize podands containing two terminal tetrazolo[1,5-а]dihydropyrimidine groups. Byproducts were isolated and identified as podands containing different substituents – one 4,7-dihydrotetrazolo[1,5-а]pyrimidine ring system and a free hydroxy group at the other terminus of the polyether chain. Analogous differently substituted podands, including one 3,4-dihydropyrimidine-2(1H)-thione moiety, were isolated from the reactions of 3-oxobutanoate-containing polyethers with benzaldehyde and thiourea.