【正文】 e 1) is added gradually over a period of 30 ，108g（）的丁二酮和482g（）的乙二酸二乙酯在515℃下低溫混合，在30分鐘內(nèi)逐步滴加到溶液中。 in an ice bath and ℃下冰浴攪拌。The colorless distillate is carefully fractionated to obtain 94–100 ，得到無色的流出液94100g反應式：2Methyl4ethoxalylcyclopentane1,3,5trione. A solution of sodium ethoxide is prepared in a 2l. threenecked, roundbottomed flask fitted with a mercurysealed stirrer, a reflux condenser carrying a drying tube, and a stopper by the addition of g. (3 moles) of sodium to 950 ml. of absolute ethanol. （3mol）鈉和950ml無水乙醇在配有干燥回流冷凝管和汞封攪拌器的2L三口圓底燒瓶中制備乙醇鈉。The extracts are bined, washed consecutively with 100 ml. of water and 100 ml. of 5% aqueous sodium bicarbonate solution, dried with anhydrous sodium sulfate, and transferred to a shortnecked distillation flask. 合并萃取液，用100ml水和100ml 5%的小蘇打洗滌，用無水硫酸鈉干燥。Part of the cold aqueous layer is added to the reaction flask to depose whatever part of the reaction mixture remains there, and the resulting mixture is added to the ，然后合并到燒杯中。 on a steam bath for 1 ，熔融混合物在8085℃蒸氣浴下攪拌1小時。Bromine (128 g., mole) is added dropwise to the wellstirred mixture over a period of 40 minutes (Note 4). 在40分鐘內(nèi)在攪拌下把溴緩慢滴加到混合物中。. 然而，速度不能太快，當反應溫度超過180℃時。 Turning of the stirrer by hand or more rapid addition of ketone is necessary at this point. 在這時，改用手動攪拌或快速滴加酮是非常必要的。Considerable heat is evolved, and, if the drops of ketone are not dispersed, darkening or charring occurs. 放熱反應，假如滴加的酮不能被分散，就會變黑或是碳化。.. . . ..About 216–224 g. (– moles) of powdered anhydrous aluminum chloride is added to a 1Lthreenecked (– moles)的無水三氯化鋁。 While the freeflowing catalyst is stirred (Note 3), 81 g. ( mole) of acetophenone is added from the dropping funnel in a slow stream over a period of 20–30 minutes. 自由流動的催化劑邊攪拌邊用滴液漏斗緩慢滴加81g苯乙酰。When about onethird of the acetophenone has been added, the mixture bees a viscous balllike mass that is difficult to ，反應混合物變成一個很難攪拌的粘性的球狀團塊。The addition of ketone, however, should not be so rapid as to produce a temperature above 180176。Near the end of the addition, the mass bees molten and can be stirred easily without being either heated or cooled. The molten mass, in which the acetophenone is plexed with aluminum chloride, ranges in color from tan to ，團塊開始融化，表明苯乙酰已經(jīng)和三氯化鋁混合完全，顏色也逐漸從黃褐色變?yōu)樽厣fter all the bromine has been added, the molten mixture is stirred at 80–85176。 The plex is added in portions to a wellstirred mixture of l. of cracked ice and 100 ml. of concentrated hydrochloric acid in a 2l. beaker (Note 6).。 The dark oil that settles out is extracted from the mixture with four 150ml. portions of ether 分四次把深色的油從混合物中用150ml萃取出來。The ether is removed by distillation at atmospheric pressure, and crude 3bromoacetophenone is stripped from a few grams of heavy dark residue by distillation at reduced pressure. 乙醚在常壓下蒸餾，微量的溴苯乙酮通過減壓蒸餾的方法從大量深色殘渣中被分離出來。The soluti