Yield: 96.4%

Reaction Conditions:

with sulfuric acid;nitric acid at 30 - 35; for 2 h;

Steps:

2 Example 2 Preparation of 2,4-Diamino-5-nitro-6-hydroxypyrimidine
Dissolve 126 g of diaminopyrimidine730 g of the above batch of filtrate, stirring, temperature control 30 ~ 35 °C,Add 20g of concentrated sulfuric acid,The mass concentration is 98%.After the dropwise addition, 68.5 g (1.01 mol) of 93% fuming nitric acid was continuously added dropwise at 30 to 35°C.After dripping, continue the incubation for 2 hours.After the reaction is completed, cool and crystallize to -5~0°C and filter.About 730 g of brownish red filtrate was obtained as the next batch of reaction solvent.The cake was washed with 100 mL of dichloromethane,200mL drinking water washing, draining,225 g (of 165 g) was obtained as a tan-yellow-brown red solid, i.e. a nitropyrimidine (MW 171.11) wet product.HPLC purity 98.7%, measured as diaminopyrimidine,The yield was 96.4%.

References:

Weifang Aotong Pharmaceutical Co., Ltd.;Yang Zaigen;Li Xi;Yan Jinhua;Zhou Zhiwei CN107903215, 2018, A Location in patent:Paragraph 0039-0050