Abstract
6-Substituted--3-(2 -pyridyl)-1, 2, 4-triazin-5-ones were synthesized in good yields by -t je reaction of a-ket6 darbexylic acids, a-keto esters and ev-thiocarbamoyl ester with 2-pyridylamidrazone.
6-Methyl-3-(2 -pyridyl)-1, 2, 4-triazin-5-one (4 a) was obtained by th-e. rgacSign. of. py-ruvic acid or ts esier with 2-pyridylamidrazone, and 6-phenyl-3-(2 -pyridyl)-1, 2, 4-triazipr5-gng (4 b) Li ag similarly obtaineMd from phenylglyoxalic. acid. gr.. its e-stgr, . but th-e reac. tigKof diethyl iM esi-oVialate with 2Lpyridylamidrazone afforded 3-(2 pyridyl)-1, 2, 4-triazin-5-gn-e (.4d)
The reaction of ethyl thiono-oxamate with 2-pyridylamidrazone afforded 6-amino-31(2ft- hQ1n)5: 0neN (11a), which was cyclized on treatment with phostuphgr-us pep-tas. ulfi-. dpe. tAo. g Fe t-e fo -cyVcfe wl th i new ring system, 6-rnethyl-3-(2 -pyridyl)-(1, 3)-thiazolo(s, 4-e)(1, 2, 4)triazine (12).
