Tert-butyl 3-[6-chloro-2-(2,2-dimethylpropanamido)pyridin-3-yl]-3-hydroxypropanoate (4 g, 11 mmol) was used as a raw material, which was dissolved in a mixed solution of 1 M HCl/dioxane (1:1, 50 mL) and reacted overnight. After completion of the reaction, ice water was added to the mixture and the precipitated solid was collected by filtration and dried to afford 7-chloro-1,8-diazanaphthalen-2-ol (1.7 g, 9.4 mmol, 86% yield). The obtained product could be used in the subsequent reaction without further purification.LC-MS analysis showed the (M-H)-peak was 181.1.