摘要
以有机碱为催化剂,CO2与伯胺反应合成了N,N′-二取代脲;考察了有机碱种类、伯胺碳链长度、反应温度、CO2压力、反应时间、催化剂用量对合成反应的影响。实验结果表明,随伯胺碳链的增长,催化剂的碱性增强,N,N′-二取代脲的收率增加;脂肪族N,N′-二取代脲的收率明显高于芳香族N,N′-二取代脲。在所选用的有机碱中,1,5,7-三氮杂双环[4.4.0]葵-5-烯(TBD)催化剂的活性最高。以正丁胺为反应基质、TBD为催化剂,合成N,N′-二丁脲的最佳反应条件为:反应温度180℃,CO2压力10.0M Pa,反应时间10h,TBD摩尔分数5.0%(基于正丁胺);在此条件下,N,N′-二丁脲的收率为81.8%;红外光谱表征结果表明,合成的产物为N,N′-二丁脲。
N, N＇ - Disubstituted ureas, used as intermediates for synthesis of pesticides, resin precursors and carbamates, were synthesized from carbon dioxide and primary amines （namely n - propylamine, n - butylamine, n - amylamine, n - hexylamine, benzylamine and aniline） over organic base catalysts. Effects of organic base types, carbon chain length of primary amine, carbon dioxide pressure, catalyst dosage, reaction temperature and time on the synthesis were investigated. Yield of N, N＇ -disubstituted ureas increases along with carbon chain length of primary amine and catalyst basicity. Yields of aliphatic N, N＇ - disubstituted ureas are much higher than those of aromatic N,N＇-disubstituted ureas. Under optimal conditions： n - butylamine as primary amine, 1,5, 7 - triazabicyclo[4.4.0]dec -5 -ene （TBD） as catalyst, reaction temperature 180 ℃, time 10 h, CO2 pressure 10. 0 MPa, TBD mole fraction 5.0% （based on n -butylamine）, yield of N,N＇ - dibutylurea is 81.8%. The prepared N,N＇ -dibutylurea was separated from products and identified by IR spectrometry.
出处
《石油化工》
CAS
CSCD
北大核心
2007年第7期721-725,共5页
Petrochemical Technology
关键词
二氧化碳
伯胺
N
N'-二取代脲
有机碱
正丁胺
N
N'-二丁脲
催化剂
carbon dioxide
primary amine
N, N＇ -disubstituted urea
organic base
n- butylamine
N, N＇ - dibutylurea
catalyst
