Are there alternatives to 4-Chloropyrrolo[2,1-f][1,2,4]triazine in synthesis?

In synthesis, alternatives to 4-Chloropyrrolo[2,1-f][1,2,4]triazine include other heterocyclic compounds like 4-bromo-pyrrolo[2,1-f][1,2,4]triazine or other nitrogen-containing heterocycles. Isomers such as 4-fluoropyrrolo[2,1-f][1,2,4]triazine can also be used as substitutes depending on the specific reaction conditions and desired product properties. Common reagents that can serve as alternatives include various chloro- or fluoro-substituted heterocycles.