英语翻译1.ProcedureIn a 1-l.round-bottomed flask are placed 250

英语翻译
1.Procedure
In a 1-l.round-bottomed flask are placed 250 cc.of glacial acetic acid,15 g.of red phosphorus,and 5 g.of iodine.The mixture is allowed to stand for fifteen to twenty minutes until the iodine has reacted,and then 5 cc.of water (Note 1) and 100 g.(0.44 mole) of benzilic acid (p.89) are added.A reflux condenser is attached,and the mixture is boiled continuously for at least two and one-half hours.After the reaction is complete,the hot mixture is filtered with suction to remove the excess red phosphorus (Note 2).The hot filtrate is slowly poured into a cold,well-stirred,filtered solution of 20–25 g.of sodium bisulfite in 1 l.of water (Note 3).This procedure removes the excess iodine and precipitates the diphenylacetic acid as a fine white or slightly yellow powder (Note 4).The product is filtered with suction,washed with cold water,and dried thoroughly on filter paper.The yield is 88–90 g.(94–97 per cent of the theoretical amount) of a solid melting at 141–144° (Note 5).If a crystalline product is desired,the acid is dissolved in about 500 cc.of hot 50 per cent alcohol and then cooled.The melting point after recrystallization is 144–145°.
2.Notes
1.In place of phosphorus,iodine,and water,a dilute solution of hydriodic acid and phosphorus may be used.
2.If difficulties are encountered in filtering the hot acetic acid solution through filter paper,an asbestos filter may be prepared and used to advantage.
3.Some samples of sodium bisulfite caused part of the diphenyl-acetic acid to dissolve.This can always be avoided if,after the solution of sodium bisulfite is prepared,a current of sulfur dioxide is passed in,until the solution is acid to litmus.
4.Sometimes,if the acetic acid solution is poured into the water too rapidly,the product will be slightly pink and a reprecipitation from acetic acid solution will be necessary.
5.The melting points of benzilic acid and diphenylacetic acid lie very close together.However,it is very easy to test for complete reduction by treating a little of the product with cold concentrated sulfuric acid.If even a trace of benzilic acid remains the sulfuric acid will turn red.
3.Discussion
Diphenylacetic acid can be prepared by the reduction of benzilic acid with hydriodic acid and red phosphorus,1 by carbonation of the reaction product of phenylsodium and diphenylmethane,2 and by hydrolysis of 1,1-dichloro-2,2-diphenylethylene.3

1 过程
在1升圆底烧瓶中放入250ml冰醋酸、15g红磷、5g碘.混合物静置15-20分钟使碘完全反应.随后加入5ml水（注1）和100g（0.44mol）羟基二苯乙酸.将回流冷凝管连在烧瓶上,连续沸腾至少2.5小时.待反应完全,将反应混合物进行抽滤,除去过量的红磷（注2）.热滤液缓慢倒入装有冷的、20-25g硫酸氢钠的1L水溶液中,并不断搅拌（注3）,从而除去过量的碘,并使二苯乙酸以细的白色或淡黄色粉末析出（注4）.将固体产物抽滤后,以冷水水洗,在滤纸上完全干燥.产率为88-90g（94%）,熔点为141-144度（注5）.如希望得到晶体,可将酸溶解在热的50%乙醇水溶液中,并冷却过滤.重结晶后,产物的熔点是144-145度.
2 注
1. 可以将稀氢碘酸溶液和磷代替磷、碘和水的混合物.
2.如难以通过滤纸过滤热醋酸溶液,可自制asbestos过滤器用于过滤.
3.一些硫酸氢钠产品会使二苯乙酸溶解.可以在硫酸氢钠溶液中通入二氧化硫气体,直至酸化完全.
4.有时,如乙酸溶液倒入水中的速度太快,产物会略带粉红,这样就必须重做乙酸的析出.
5.羟基二苯乙酸和二苯乙酸的熔点非常接近.但是,通过少量产物测试可以很容易区分,即以冷的浓硫酸处理,即使有微量的羟基二苯乙酸存在,也会是硫酸变红.
3 讨论
二苯乙酸可以通过羟基二苯乙酸在氢碘酸和磷中的消除反应来制备,即1苯基钠和二苯甲烷反应产物的羧基化,2 1,1-二氯-2,2-二苯乙烯的水解,3.