4-Bromo-3-chloro-7-methoxyquinoline

Synthesis

A method for synthesizing 4-bromo-3-chloro-7-methoxyquinoline comprises the following steps:
the first step is as follows: synthesis of 3-chloro-4-hydroxy-7-methoxyquinoline
Adding tetrahydrofuran (300 g), N, N-dimethylformamide (5g) and 4-hydroxy-7-methoxyquinoline (50.0 g and 0.29 mol) into a reaction bottle in sequence, stirring and dissolving, adding N-chlorosuccinimide (NCS) (38.74 g and 0.68 mol), stirring and dissolving, reacting for 2 hours at 33 ℃ until yellow solid is generated, filtering, and drying to obtain 50.43g of a 3-chloro-4-hydroxy-7-methoxyquinoline product;
the second step is that: synthesis of 4-bromo-3-chloro-7-methoxyquinoline
Acetonitrile (500g) and 3-chloro-4-hydroxy-7-methoxyquinoline (50g, 0.24mol) are sequentially added into a reaction bottle at room temperature, stirred and dissolved, the temperature is reduced to-2 ℃, tribromooxyphosphorus (172.01 g,0.6 mol) is added, the temperature is raised after the addition, the reaction is carried out for 30 minutes at 5 ℃, the reaction is carried out for 15 hours at 55 ℃, brown solid is generated, suction filtration is carried out to obtain solid, the solid is poured into ice water for dissolution, the solution is adjusted to the PH value being not less than 7 by using potassium carbonate, the solid is separated out, suction filtration, water washing and drying are carried out to obtain 58.86g of a finished product of the 4-bromo-3-chloro-7-methoxyquinoline.