4-oxobenzo[d][1,2,3]triazin-3(4H)-yl pivalate

3H-[1,2,3]triazolo[4,5-b]pyridin-3-yl pivalate

1-benzotriazolyl pivalate

4-oxopyrido[3,2-d]pyrimidin-3(4H)-yl pivalate

4-oxopyrido[3,2-d][1,2,3]triazin-3(4H)-yl pivalate