0022-3263/89/1954-4984 $01.50/0 venient synthesis of 1, 2, 4-triazin-6-ones4 and their corresponding 6-thi0nes.~~ Alkylation of the latter with 4-halo-1-butynes and 5-hdo-l- pentynes, utilizing procedures analogous to those previously employed for the preparation of 3-(alkynylthi0)-1, 2, 4-triazines,~~ provides a family of tethered diene-dienophile pairs that are attractive intermediates for the preparation of thieno [2, 3-c] pyridines and 3, 4-dihydro- ...