- METHOD FOR PRODUCING CARBAMATE AND METHOD FOR PRODUCING ISOCYANATE
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The present invention provides a method for producing a carbamate that includes a step (1) and a step (2) described below: (1) a step of producing a compound (A) having a urea linkage, using an organic primary amine having at least one primary amino group per molecule and at least one compound selected from among carbon dioxide and carbonic acid derivatives, at a temperature lower than the thermal dissociation temperature of the urea linkage; and(2) a step of reacting the compound (A) with a carbonate ester to produce a carbamate.
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- ISOCYANATE PRODUCTION METHOD
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An isocyanate production method according to the present invention is a method in which an isocyanate is produced by subjecting a carbamate to thermal decomposition, and includes: a step of preparing a mixture liquid containing the carbamate, an inactive solvent and a polyisocyanate compound; a step of conducting a thermal decomposition reaction of the carbamate by continuously introducing the mixture liquid into a thermal decomposition reactor; a step of collecting a low-boiling decomposition product by continuously extracting the low-boiling decomposition product in a gaseous state from the reactor, the low-boiling decomposition product having a boiling point lower than the polyisocyanate compound; and a step of collecting a high-boiling component by continuously extracting, from the reactor, a liquid phase component which is not collected in a gaseous state at the step of collecting the low-boiling decomposition product.
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Paragraph 0447-0450; 0459; 0478
(2020/05/02)
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- Isocyanates From Primary Amines and Carbon Dioxide: 'Dehydration' of Carbamate Anions
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Carbamate anions, derived from primary amines CO2 and an added base (e.g.NEt3), undergo rapid reaction with electrophilic 'dehydrating agents' (e.g.POCl3, P4O10) to give the corresponding isocyanates in excellent yields.
- Waldman, Thomas E.,McGhee, William D.
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p. 957 - 958
(2007/10/02)
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