Process for large-scale preparation of 2-vinyl pyridine

Abstract

The invention refers to the technique to produce 2- vinyl pyridine with the scale of industrial production. It chooses the 2-ethoxyl pyridine as the starting material, dehydrates a molecule of water to produce 2-vinyl pyridine with the existence of the catalyzer; keep the weight ratio of 2-ethoxyl pyridine:catalyzer=1:0.05-1.0 and chooses the vitriol, phosphoric acid, sodium hydroxide or potassium hydroxide as the catalyzer. The reaction condition is as follows: whisk it for between 5min and 30min at the temperature of between 100deg.C and 190deg.C, collect the fractions with boiling range of 60-100deg.C / 10-150mm / Hg, separate the water of the imputities by alkaliingout method or saltingout method to get the crude product; distill it with lower pressure, collect the fractions with boiling range of 60-100deg.C / 90-150mm / Hg and get the turnoff of the 2- vinyl pyridine. Compared with today's technology, the invention is featured by the following aspects: normal pressure, tank reactor, ecumenic requirements to the equipments, simpler production technique and higher yield.

Description

technical field

[0001] The invention belongs to the preparation of pyridine compounds, in particular to a process for preparing 2-vinylpyridine on an industrial scale. Background technique

[0002] In the prior art, 2-picoline is used as a starting material to produce 2-vinylpyridine, and its process route is a one-step process; that is, the input raw material is 2-picoline, and the product obtained after the reaction is 2-vinylpyridine. Pyridine, the intermediate 2-hydroxyethylpyridine is not isolated.

[0003] The disadvantage of this method is that the reaction temperature is relatively high (400-500°C), and the reaction pressure is relatively high (1.5Mpa is equivalent to 15kg / cm 2 ), the reactor is a pipeline type, easy to block, and the equipment needs pressure resistance and anti-corrosion, which have high requirements; the unit consumption of 2-picoline is high (1 ton of 2-vinylpyridine consumes 1.4 tons of 2-picoline), and the yield is only 63%±; the intermediate ...

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