5 H ‐Thiazolo [3,2‐ b ]‐ and 2 H ‐Thiazolo [2,3‐ c ]‐as‐triazines

Derivatives of the 5 H ‐thiazolo[3,2‐ b ]‐ and 2 H ‐thiazolo[2,3‐ c ]‐as‐triazine systems were synthesized via condensation of tetrahydro‐I‐methyl‐ as ‐triazine‐3(2 H )‐thione with ethylene dibromide and ethyl bromoacetate, respectively. An hypothesis is given for the formation of the [3,2‐ b ] system in one of these reactions and the [2,3‐ c ] system in the other. Structure proof was accomplished by an unequivocal synthesis of one of the [2,3‐ c ] derivatives.