Butanal reaction with, phosgene

King Jr reported a facile synthesis of chlorinated dioxo-lanones by a simple, one-pot, direct addition of phosgene to 1,2-diones (Ref. 225). Thus, the reaction of 2,3-butane dione with phosgene in the presence of pyridine affords trans-4,5-dichloro-4,5-dimethyl-1,3-dioxolane-2-one in 82% yield as shown in scheme 172. 

The reaction of phosgene with butanal under substantially similar conditions to those used for the reaction of phosgene with ethanal gave smaller yields of the 1,1-dichloro-derivative, and the reaction of phosgene with gaseous chloral, CCI3CHO, over activated... 

Probably the simplest polymer formation reaction involving phosgene is that with the dihydric aliphatic alcohols, such as ethylene, propylene or butylene glycol viz. ethane-1,2-diol, propane-1,3-diol or butane-1,4-diol) this reaction results in the formation of linear, wax-like polymers suitable for the impregnation of materials requiring water barrier properties [1133]. 

Subsequently, Bayer and coworkers, obtained hexane diisocyanate from the reaction of 1,6-hexamethylenediamine hydrochloride and phosgene. Tliis product was reacted with butane diol to produce several kilograms of aliphatic polyurethane. The melting point of this polymer U84 C) was too low for textile fiber applications, but it is still used for the production of bristles. 

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