Syntheses of triazolo[6,7-d]phthalide and triazolo[6,7-d]dihydrocoumarin

Triazolo[6,7-d]phthalide has been synthesized in a seven step sequence from phthalide in 24% overall yield, and triazolo[6,7-d]dihydrocoumarin has been prepared in nine steps from dihydrocoumarin in 20% overall yield. The ¹H and ¹³C nmr spectra and the tautomeric equilibria of the final compounds and intermediates are discussed.