Catalytic hydrogenation includes hydrogenation and hydrogenolysis. Most of the production and synthesis of modern drugs need catalytic hydrogenation. For example:Procaine, a drug used for anesthesia, is synthesized from p-nitrotoluene as the starting material. One of the important steps is the conversion of nitro-hydrogenation to amines.
Aminopyrine was synthesized from 4-aminoantipyrine (1,5-dimethyl-2-phenyl-4-amino-3-pyrazolone). Formic acid and formaldehyde were used for alkylation in the past, but now nickel was used for hydrogenation. A large number of raw materials such as formic acid and liquid ammonia were saved.
P-nitrophenol was prepared by reduction, esterification and etherification.
P-nitrophenol was prepared from p-nitrochlorobenzene by hydrolysis and then reduced to p-aminophenol by iron powder and hydrochloric acid. Advanced technology abroad uses nitrobenzene as raw material, platinum oxide as catalyst for hydrogenation catalysis, through benzene, and then rearranged to p-aminophenol. The reaction greatly reduced the production cost of p-aminophenol.
In the process of synthesizing caffeine by condensation of dimethylurea with cyanoacetic acid, the intermediate dimethyl-4-iminodiazide was hydrogenated and reduced to 1,3-dimethyl-4,5-aminoureazine. This synthetic route can improve the yield and quality of caffeine.
In the synthesis process of atropine, 2,5-dimethoxydihydrofuran was synthesized from furan by electrolysis. 2,5-dimethoxytetrahydrofuran was synthesized by hydrogenation catalysis. Tropicone was formed by hydrolysis, condensation, hydrogenation, salting, esterification and hydrolysis, and atropine was finally synthesized.
Other pharmaceutical synthesis processes require more hydrogenation catalytic processes. Examples include vitamin B2, vitamin B6, vitamin A, synthetic berberine, doxycycline, thiamphenicol, procainamide, adrenaline, chloroquine, spironolactone, cortisone acetate, 18-methylnorethindrone, pyrimidine, tantel, amantadine, trifluoropiperbutylbenzene, megestrol, isopropyladrenaline, thrombin Hypoglycemic Ling, methoxyamine, iodine phenylthiazide, amitriptyline, Weichangning, synthetic anisodamine, Baineiduan, acetiodobenzoic acid skin relaxation, progesterone hexanoate, dexamethasone, acetylene propionate and so on.