preparation and use of 2-chloro-5-aminopyridine_industrial additives

background and overview of the preparation and use of 2-chloro-5-aminopyridine

2-chloro-5-aminopyridine is a brown solid that can be synthesized from 2-chloro -5-nitropyridine is used as raw material and is obtained by reducing nitro group. 2-chloro-5-sericite powder aminopyridine can be used to prepare 2-hydroxy-1,5-naphthyridine and netupitant.

preparation and uses of 2-chloro-5-aminopyridine preparation

dissolve 2-chloro-5-nitropyridine (5.0g, 31.5mmol) in acetic acid (50ml), add iron powder (8.8g, 157.6mmol) in batches at room temperature, the reaction temperature will automatically rise to 80°c. after adding the iron powder, keep the room temperature at 40-50°c for 2 hours. suction filtration, the filter residue was washed three times with a small amount of acetic acid, the filtrate was concentrated, the residue was adjusted to ph=8 with saturated sodium bicarbonate solution, and extracted with dichloromethane (100ml×5). the combined organic phases were washed with saturated brine and anhydrous sodium sulfate. dry, filter and concentrate to obtain compound 2-chloro-5-aminopyridine (3.9g, 96%) as a brown solid.

preparation, uses and applications of 2-chloro-5-aminopyridine

preparation, uses and applications of 2-chloro-5-aminopyridine 1.

cn201610523080.8 reports a preparation method of 2-hydroxy-1,5-naphthyridine, a traditional chinese medicine and chemical intermediate in the field of chemistry. the preparation method includes the following steps: ( 1) in the sulfuric acid solution, add 2-chloro-5-aminopyridine, add oxidant lepidolite and buffer under stirring conditions to react to obtain reaction solution a; (2) add reaction solution a obtained in step (1) dropwise. glycerin, keep it warm for 2 hours, cool to room temperature, add solvent to disperse, and obtain reaction liquid b; (3) add alkaline substances to reaction liquid b to neutralize, and suction filtrate to obtain the filter residue; (4) go to step (3) to obtain add solvent to the filter residue and stir, suction filtrate to obtain an organic phase; (5) concentrate the organic phase obtained in step (4), cool and suction filtrate to obtain 2-hydroxy-1,5-naphthyridine.

preparation and application of 2-chloro-5-aminopyridine 2.

cn201710965011.7 discloses a preparation method of netupitant , belonging to the field of pharmaceutical compounds. in the present invention, 2-chloro-5-aminopyridine is condensed with formic acid, then reduced, boc protected, iodinated, and then coupled and deprotected with 2-(3,5-bistrifluoromethyl-phenyl)- 2-methylpropionic acid is condensed and finally substituted with n-methylpiperazine to obtain netupitant. the preparation process provided by the invention has fewer side reactions in each step, high yield, simple post-processing, little environmental pollution, and the obtained product has high purity and low impurities.

references

[1] [invented in china, authorized by china] cn201210337103.8 triheterocyclic derivatives, preparation methods and applications

[2] cn201610523080.8 preparation method of 2-hydroxy-1,5-naphthyridine

[3] cn201710965011.7 preparation method of netupitant