2//-Thiazolo tetrazin-6-ones

Arylidene-33-diethyl-3,4,6,7-tetrahydro-2//-thiazolo[3,2-/j][l, 4 ]-tetrazin-6-ones 53 have been synthesized in a single step by the condensation of tetrahydro-l, 4 -tetrazin-3-thione 52 with ethyl chloioacetate and aldehydes in the presence of pyridine and piperidine. Condensation of 53 with hydrazine afforded fused derivatives 54 <98IJC(B)819>. 

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