Cooling bath, Dry Ice and ethylene

Cooling bath, Dry Ice and ethylene glycol monomethyl ether, 32,43 Dry Ice and methylene chloride, 34, 38... 

A 250-mL poly(chlorotrifluoroethylene) vessel was charged with TaFj (2.2 g, 8 mmol). The vessel was evacuated, cooled in liquid Nj and charged by distillation with HF (20.0 g, 1.0 mol). The vessel was filled with N2 and immersed in a bath of water and ethylene glycol at 5 C. Trichloroethene (108 g, 0.8 mol), cooled to 0 C, was added in one portion. The resulting mixture was stirred for 2.5 h. The mixture was poured over cracked ice (40 g). The organic layer was separated, washed with HjO, and dried (anhyd CaCl2) to give 116.7 g of crude product, which was distilled yield 108.1 g (89%) bp 87-89 C. 

Place a mixture of 1 0 g. of the hydrocarbon, 10 ml. of dry methylene chloride or ethylene dichloride or syw.-tetrachloroethane, 2 5 g. of powdered anhydrous aluminium chloride and 1-2 g. of pure phthalic anhydride in a 50 ml. round-bottomed flask fitted with a short reflux condenser. Heat on a water bath for 30 minutes (or until no more hydrogen chloride fumes are evolved), and then cool in ice. Add 10 ml. of concentrated hydrochloric acid cautiously and shake the flask gently for 5 min utes. Filter oflf the solid at the pump and wash it with 10-15 ml. of cold water. Boil the resulting crude aroylbenzoic acid with 10 ml. of 2 -5N sodium carbonate solution and 0 2 g. of decolourising carbon for 5 minutes, and filter the hot solution. Cool, add about 10 g. of crushed ice and acidify... 

When all has been added (Note 2), 278 g. (6.3 moles) of ethylene oxide (Note 3) (previously dried with soda lime) is added through a tube (3 or 4 mm. in diameter) the end of which is about 20 mm. above the surface of the liquid (Note 4), the temperature being kept below 10° by cooling in an efficient ice-and-salt bath (Note 5). This addition requires four to six hours. When all has... 

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