Mitsubishi Chemical Corporation

Kouji Teramoto

Hitoshi Nishimura

Yasuharu Mori

Yu Kanda

Toshio Uchibori

Makoto Tezuka

Noritsugu Ooishi

Hidefumi Sano

A method for purifying an N-(&#x3b1;-alkoxyethyl)formamide contained in a mixture thereof with a plurality of distillation columns, the plurality of distillation columns being arranged serially, the method including condensing a distillate from the second or any later-stage distillation column to obtain a condensate and returning at least some of the condensate to the preceding distillation column.

Method for purifying N-(alpha-alkoxyethyl)formamide, method for producing high-purity N-(alpha-alkoxyethyl)formamide, and device for purifying N-(alpha-alkoxyethyl)formamide

Provided are a method for producing N-(&#x3b1;-alkoxyethyl)formamide, comprising adding an acid catalyst to the mixed liquid within 3 hours from start of mixing after mixing of N-(&#x3b1;-hydroxyethyl)formamide with an alcohol has been started, by which the N-(&#x3b1;-alkoxyethyl)formamide can be produced at a high yield without additional investment in plant and equipment while suppressing an increase in the temperature of the mixed liquid and preventing corrosion of a pipe; and a method for producing N-(&#x3b1;-alkoxyethyl)formamide, comprising degassing carbon dioxide in the reaction of N-(&#x3b1;-hydroxyethyl)formamide with an alcohol, by which the N-(&#x3b1;-alkoxyethyl)formamide having a decreased carbonate concentration can be produced.

Method for producing N-(alpha-alkoxyethyl)formamide

A method for producing N-vinylformamide through a vapor-phase thermal decomposition reaction using an evaporator () for evaporating a raw material, a thermal decomposition reactor () for thermally decomposing a raw material gas generated by the evaporator () and a condenser () for condensing a thermally decomposed gas generated by the thermal decomposition reactor (), wherein the evaporation of the raw material is started in the evaporator () while the temperature of a tube wall of a first connection tube () that connects the evaporator () to the thermal decomposition reactor () satisfies a requirement represented by formula (1): (temperature of tube wall (&#xb0; C.))&#x2265;0.37&#xd7;(pressure of evaporator (mmHg))+205.

Method for producing N-vinylformamide

The present invention provides a method for producing .epsilon.-caprolactam, which comprises subjecting cyclohexene to a hydration reaction to obtain cyclohexanol, subjecting the cyclohexanol to a dehydrogenation reaction to obtain cyclohexanone, subjecting the cyclohexanone to an oxime-forming reaction to obtain cyclohexanone oxime, and subjecting the cyclohexanone oxime to a Beckmann rearrangement reaction to obtain .epsilon.-caprolactam, wherein methylcyclopentanones contained in the cyclohexanone subjected to the oxime-forming reaction are controlled to be not more than 400 ppm. According to the present invention, it is possible to produce .epsilon.-caprolactam having a quality not inferior to conventional quality at a low cost.

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Tokyo, Japan

Kouji Teramoto