| 摘要 |
PURPOSE:To prevent recombination with hydrogen chloride and obtain the titled compound with good productivity, by condensing a thermal decomposition gas of an N-alkylcarbamoyl chloride in a cooling part of a straight-pipe, multitubular and vertical type condenser and dripping the condensate into the inner wall of a lower compartment having a large tilting angle. CONSTITUTION:An N-alkylcarbamoyl chloride having a 1-3C alkyl group is heated in an inert organic solvent having a higher boiling point than that of the formed N-alkyl isocyanate and decomposed into hydrogen chloride and the N-alkyl isocyanate. The resultant thermal decomposition gas is then continuously fed from an inlet 1 into a straight-pipe, multitubular and vertical type condenser and condensed in a cooling part consisting of cooling tubes 7. The resultant condensate is dripped into the lower compartment 8 having >=50%, particularly >=70% ratio of the vertical projected area of collision surface at 50-85 deg. tilting angle (theta) to the total vertical projected area thereof and continuously taken from a condensate outlet 3. The dripping condensate is prevented from misting by increasing the tilting angle (theta) to prevent recombination.
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