Novel method for preparing 4-isopropylpyridine

Abstract

The invention discloses a novel method for preparing 4-isopropyl pyridine. The method comprises the following steps: reacting methyl isonicotinate serving as an initial raw material with a chloromethane Grignard reagent to obtain 4-isopropyl pyridine, reacting the 4-isopropyl pyridine with thionyl chloride to obtain 4-(2-chlorine) isopropyl pyridine; and carrying out hydrogenation reduction on the4-(2-chloro) isopropyl pyridine and palladium on carbon to obtain the 4-isopropyl pyridine. The method has the advantages that: the initial raw material is a large industrial raw material, the methylchloride Grignard reagent has more price advantage than a traditional methyl iodide Grignard reagent or methyl bromide Grignard reagent, and the molecular weight is far less than that of methyl iodide or methyl bromide, so that the dosage is greatly reduced; and almost no three wastes are generated in the last step of hydrogenation reduction. The method is simple to operate, less in three wastes,environmentally friendly, high in conversion rate, low in cost and obvious in market competitive advantage, and almost no by-product is generated.

Description

technical field [0001] The invention belongs to a pharmaceutical intermediate (3-hydroxy-4-amino-butan-2-yl)-3-(2-thiazol-2-yl-pyrrolidinyl-1-carbonyl) benzamide and derivatives thereof (β-secretase inhibitor, mainly used for the treatment of Alzheimer's disease) and an important intermediate of new marine antifouling biocide diphenyl-methyl-4-isopropylpyridyl boron (KM-2) The synthesis and application of the invention belong to the technical field of pharmaceutical manufacturing. Background technique [0002] Alzheimer's disease (AD) is a progressive neurodegenerative disease with insidious onset. Clinically, it is characterized by generalized dementia such as memory impairment, aphasia, apraxia, agnosia, impairment of visuospatial skills, executive dysfunction, and changes in personality and behavior. The etiology is still unknown. Those with onset before the age of 65 are called Alzheimer's disease; those with onset after the age of 65 are called senile dementia. β-sec...

AI Technical Summary

Problems solved by technology

[0003] At present, if the bottom of a ship, fishing nets, seawater supply and drainage pipes, and underwater structures are exposed to water for a long time, they will adhere to and reproduce oysters, mussels, barnacles and other animals, seaweed and other plants or bacteria on their surfaces. species of aquatic organisms, their function may be disrupted

In particular, if such aquatic organisms adhere to and reproduce on the bottom of the ship, the surface roughness of the hull will increase, resulting in a decrease in ship speed and an increase in fuel costs.

In addition, a lot of manpower and operating time are required to remove these organisms from the bottom of the ship

In addition, if these aquatic organisms attach to, reproduce and cultivate nets or other fixed nets, it may cause blockage of the mesh, causing hypoxia of fishing, hunting or breeding organisms, resulting in death and loss

In addition, these organisms adhere to and multiply on the water supply and drainage pipes of thermal or nuclear power plants, which may have a negative impact on the supply cycle of cooling water.

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