问题：求帮忙翻译，加分
类型：求助 (悬赏分:3分)
提问：quick208
等级：▲
版块：有机化学问题(jimuwei,fpcwin1211,netpanda,yjgzfl,Ftian,)
信誉：95%
回复：3
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时间：2008-01-07 18:47:22 编辑加入/取消收藏订制/取消短消息举报该贴

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.

回复人：quick208,▲ (以父之名) 时间：2008-01-07 19:32:33 编辑	1楼
已经打分了！

回复人：hqzhang,★★ (配位化学，物理化学) 时间：2008-01-07 19:07:25 编辑

2楼

1.步骤
在1 - 1 。圆底烧瓶放置250ML冰醋酸， 15 g.红磷和5 g.碘酒。该混合物保持15至20分钟，直到碘反应，然后加5ml水（注1 ）和100 g. （ 0.44摩尔） benzilic酸（第89页）。放在回流冷凝器里混合煮沸，不断搅拌至少有两个或一个半小时。在反应完全后，炎热的混合物过滤，以除去过剩的红磷（注2 ）。热滤液正慢慢倒入凉的20-25 g亚硫酸氢钠水溶液（注3 ）。这个步骤除去了过多的碘和白色或略有黄色粉末的二苯乙酸沉淀了（注4 ）。该产品是过滤与吸，洗冷水，并充分干燥滤纸上。产量是88-90 g. （ 94-97 ％的理论值）的固态熔点在141-144 ° （注5 ）。如果一个结晶产品，是理想的，酸溶解在约500ml。热百分之五十酒精，然后冷却。重结晶后测熔点，是144-145度.

[该帖子已被hqzhang在2008-01-07 19:07:44编辑过]

回复人：tangyyer,★★★★★ (有空来逛逛my blog: http://tangyyer.blog.hexun.com) 时间：2008-01-07 19:08:09 编辑	3楼
建议你先看看二苯乙酸的合成，中文文献有不少。如果困难的话，没有必要看英文。

得分人：tangyyer :3,

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