1-benzyl-5-bromo-3,6-dimethyl-1H-pyrazolo[3,4-b]pyrazine 、
1-(1-ethyl-propyl)-3,6-dimethyl-1H-pyrazolo[3,4-b]pyrazine 以to give 5-bromo-1-(1-ethyl-propyl)-3,6-dimethyl-1H-pyrazolo[3,4-b]pyrazine的产率得到5-bromo-1-(1-ethyl-propyl)-3,6-dimethyl-1H-pyrazolo[3,4-b]pyrazine