- A safe and efficient procedure to prepare alkyl and alkoxyalkyl chlorides and dichlorides by catalytic decomposition of the corresponding alkyl and alkoxyalkyl chloroformates and bischloroformates with hexabutylguanidinium chloride
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Small amounts of hexabutylguanidinium chloride (0.01 mol%) decomposes pure chloroformates or bischloroformates with different lengths of carbon chains by a semicontinuous process to diminish run-away risk, leading to chloride compounds with high yield and purity.
- Violleau,Thiebaud,Borredon,Le Gars
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- Preparation method of -[1,2-ethanediylbis(oxy-2,1-ethanediyl)] ester
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The invention discloses a preparation method of -[1,2-ethanediylbis(oxy-2,1-ethanediyl)] ester. According to the preparation method, gaseous phosgene and diethylene glycol serve as the reaction raw materials, a -[1,2-ethanediylbis(oxy-2,1-ethanediyl)] ester product serves as solvent, and the -[1,2-ethanediylbis(oxy-2,1-ethanediyl)] ester product of which the content is larger than 98.5% and the yield is larger than or equal to 99.0% is prepared, wherein the gaseous phosgene is subjected to low temperature liquefaction and gasfication to remove a trace amount of tar and metal impurities and then subjected to concentrated sulfuric acid washing to remove a trace amount of water. The total content of metal of iron, chromium and nickel in -[1,2-ethanediylbis(oxy-2,1-ethanediyl)] ester is decreased to 1.0 ppm or below, and the water content is 0.01%. According to the preparation method, the reaction is conducted completely, the yield is high, byproduct bipolymer and metal impurities are greatly reduced, the production cost is low, and the prepared -[1,2-ethanediylbis(oxy-2,1-ethanediyl)] ester product is high in purity, long in preservation time, stable in product quality and still colorless and transparent after being preserved for six months and completely meets the requirement of resin production on polymeric monomers.
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Paragraph 0022; 0023; 0024
(2016/11/17)
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- Bis(aminoneopentyl) aromatics
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Aromatic-aliphatic diamines of the formula STR1 in which Ar is an arylene or substituted arylene are useful in preparing thermally stable, rigid, polyamides, polyureas and polyurethanes having a repeating unit of the formula STR2 in which Ar is arylene or substituted arylene, X is --NH-- or --O--, n is 0 or 1, and R is a divalent organic radical.
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