【正文】 銅即顯紫紅色或紫色，這種顏色反應(yīng)稱縮二脲反應(yīng)。凡分子結(jié)構(gòu)中含兩個(gè)或以上酰胺鍵（ ）即肽鍵的化合物均可發(fā)生這種顯色反應(yīng)，因此可用縮二脲反應(yīng)鑒別多肽和蛋白質(zhì)。3．巴比妥類藥物 巴比妥酸又稱丙二酰脲，可由尿素與丙二酰氯或丙二酸二乙酯在乙醇鈉的催化下進(jìn)行縮合反應(yīng)制備。丙二酰脲為無色結(jié)晶，微溶于水，在水溶液中存在酮式—烯醇式互變異構(gòu)平衡， 烯醇式（pKa=）顯示出比乙酸（pKa=）還強(qiáng)的酸性，故稱為巴比妥酸。 巴比妥酸本身無鎮(zhèn)靜催眠作用，當(dāng)它的五位亞甲基上的兩個(gè)氫被烴基取代后才呈現(xiàn)鎮(zhèn)靜催眠的生理活性，是一類對中樞神經(jīng)系統(tǒng)起抑制作用的化合物。這些巴比妥酸的衍生物總稱為巴比妥類藥物。例如：巴比妥： R′=R〞=–C2H5 長效苯巴比妥： R′=–C2H5 , R〞=C6H5– 長效異戊巴比妥：R′=–C2H5 , R〞=–CH2CH2CH(CH3)2 中效The carboxylic acid is the organic pound containing carboxy are present in or derived from many natural substances. The names monly used for carboxylic acids originate from the early sources of these pounds. The fatty acid in the fat has three kinds of code systems。pπconjugation system existing in the carboxyl is the structure characteristic of carboxylic acid， This kind of pπconjugation effect makes the carbonyl in the carboxyl the nucleophilic addition reaction activity to be reduced； The OH bonds polarity increase which makes the hydroxyl group acidic。The acidity of the Carboxylic acid to depends on its induction effect, conjugative effect and steric effect. In the fatty acid, the carboxyl group is joined while electron withdrawing group, strengthen acidly。 the carboxyl group is joined while electron donation group, weaken acidly. The hydroxyl in the carboxyl can be replaced and produces the carboxylic acid derivative in the carboxylic acid. The carboxyl can be returned into primary alcohol by LiAlH 4 of strong reducing of carboxylic acid takes place the halogenation reaction, which needs a small amount of phosphorus act as the catalyst. When the dicarboxylic acids of different structure is heated, they can undergoe decarboxylation or dehydration reaction.The carboxylic acid derivative（ acyl halide , acid anhydride , ester and amide ) all contain the acyl group in the molecules. The carboxylic acid derivative can take place hydrolysis, alcoholysis and aminolysis reactions，these reaction are all nucleophilic substitution , react mechanism is additionelimination process. The active order of nucleophilic substitution that the carboxylic acid derivative takes place is: acyl halide Acid anhydride Ester amide .The reaction of introducing the acryl group to organic molecule is called the acidylation ， the chemical pound can offer acryl group called the acidylating agent，the monly used acidylating agents are acryl halide and acid anhydride. Esters with alpha hydrogen can undergo elfcondensation reaction to yield β–keto esters. The carbonic acid can be regarded as the hydroxyl formic acid。 the hydroxyl in the molecule is replaced and can produce the carbonic acid derivative. A urea has general chemical nature of amide。 in addition heating the urea can turne into biruet. The biruet can develop the color with the cupric sulfate in the alkaline solution, we call that the biruet reaction. Malonyl urea has acidity, so we call it barbituric acid. The chemical pound after the methylene of barbituric acid is replaced by the alkyl radical has sedation and syngignoscism function.習(xí) 題1．命名下列化合物。（1） （2）（3） （4）（5） （6） 2．寫出下列化合物的結(jié)構(gòu)式。（1）異丁酸叔丁酸 （2）2甲基2環(huán)己基丙酸（3）丁二酸甲乙酸 （4）鄰乙酰氧基苯甲酸（5）琥珀酸酐 （6）1，3丙二醇二乙酸酯（7）N乙基1，2環(huán)己烷二甲酰亞胺3．完成下列反應(yīng)（1）（2）（3）（4）（5）（6）（7）（8）（9） （10）（11）（12）（13）4．制取乙酸苯酯不宜用乙酸與苯酚直接發(fā)生酯化反應(yīng)制取，若以乙酸和苯酚為原料，應(yīng)采用那種方法制取乙酸苯酯？寫出反應(yīng)式。5．將下列化合物按酸性增強(qiáng)的順序排列。（1）甲酸、乙酸、三氯乙酸、苯甲酸（2）甲酸、草酸、丙二酸、丁二酸6．按指定性質(zhì)由小到大排列成序。（1）水解活性：乙酸酐、乙酸乙酯、乙酰胺、乙酰氯（2）酯化反應(yīng)難易：（3）與苯酚 反應(yīng)的快慢：丙酸、丙酰氯、丙酸酐（4）水解反應(yīng)速度：7．用化學(xué)方法鑒別下列化合物（1）甲酸、草酸、乙酸（2）馬來酸、乙酰氯、丁二酸（3）硬脂酸、亞油酸（4）芐醇、水楊酸、苯甲酸8．完成下列轉(zhuǎn)變（1）乙烷 → 乙酰乙酸乙酯（2）正丁醇 → 正丙胺（3）丙酸 → 丁酸（4）丙酸 → 丙烯酰氯9．化合物A、B、C分子式均為C4H6O4，A、B可溶于NaHCO3溶液，A加熱生成C4H4O3，B加熱生成C3H6O2，化合物C用稀酸處理可得D和E，用高錳酸鉀氧化D和E均只生成二氧化碳和水。寫出A、B、C的結(jié)構(gòu)式。10．化合物A的分子式為C5H6O3，它能與1mol 乙醇作用得到兩個(gè)互為異構(gòu)體的化合物B和C。B和C分別與氯化亞砜作用后再與乙醇作用，兩者都生成同一化合物D，試推測A、B、C、D的結(jié)構(gòu)并寫出有關(guān)反應(yīng)式。 222 / 25