Preparation of 3-pyridinecarboxaldehyde_Industrial additives

Preparation background and overview of 3-pyridinecarboxaldehyde

As an important pharmaceutical intermediate and fine chemical raw material, 3-pyridinecarboxaldehyde has a wide range of applications and broad market prospects. In medicine, 3-pyridinecarboxaldehyde, as an important pharmaceutical intermediate, can be used to synthesize the laxative bisacodyl and is also a raw material for the synthesis of the organophosphate antidote pralidoxime. Recently, it has been reported that 3-pyridinecarboxaldehyde can also be used to synthesize the laxative bisacodyl. Raw material for anti-HIV protease inhibitors; in agriculture, 3-pyridinecarboxaldehyde is a necessary intermediate for the synthesis of aminoguanidine bicarbonate of some acaricides; in the photosensitive industry, 3-pyridinecarboxaldehyde can be used to synthesize nitrogen-containing heterocyclic colors Photographic materials.

Preparation of 3-pyridinecarboxaldehyde

3-methylpyridine reacts with glacial acetic acid and hydrogen peroxide. The reaction temperature is 63°C and the reaction time is 17h. The molar ratio of 3-methylpyridine, glacial acetic acid and hydrogen peroxide is 1:4:3.5, and 3-methylpyridine is obtained. Pyridine nitrogen oxide; 3-pyridine nitrogen oxide reacts with acetic anhydride, the reaction temperature is 92°C, the reaction time is 4h, the molar ratio of the 3-pyridine nitrogen oxide and acetic anhydride is 1:2.3, and acetic acid-3 is obtained -Pyridine methyl ester; 3-pyridine methyl acetate reacts with potassium hydroxide solution. The reaction time is 5 hours. The molar ratio of 3-pyridine methyl acetate to potassium hydroxide is 1:1.8. The reaction gives 3-pyridine. Methanol; 3-pyridinemethanol is cooled with ice water and PCC is added. The molar ratio of 3-pyridinemethanol to PCC is 1:2.5, and the temperature is 2°C; then the reaction is carried out at room temperature, the temperature is 23°C, and monitored by thin layer chromatography. Complete reaction.

Preparation and application of 3-pyridinecarboxaldehyde

CN201811091233.1 discloses a preparation method of Cordil nipyridinyl acetate, which includes the following steps: Synthesis of 3-pyridine oxazolidine: Add aminoethanol to the alcohol solution of 3-pyridine carbaldehyde under stirring and solid brominated reagent, stir at room temperature until 3-pyridinecarboxaldehyde is consumed; quench the reaction system with a saturated solution of sodium thiosulfate, extract with ethyl acetate, and concentrate the organic phase to obtain crude 3-pyridineoxazolidine; Nicol Synthesis of dil: Dissolve 3-pyridine oxazolidine in a solvent, then add nitrite, heat, add oxygen-containing gas, stir until 3-pyridine oxazolidine is consumed; quench with saturated sodium sulfate solution , extracted with ethyl acetate, concentrated, and the crude product was dissolved with 30% ethyl acetate in n-hexane solution, cooled to 10 degrees, solid precipitated, filtered, and nicorandil was obtained.

References

[1] [Chinese invention] CN201911167747.5 A synthesis method of 3-pyridinecarboxaldehyde

[2] CN201811091233.1 Preparation method of nicorandil