制藥工程 藥物化學(xué)實(shí)驗(yàn)講義

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1、 THE EXPERIMENTS OF MEDICINAL CHEMISTRY （供藥學(xué)、藥劑、制藥工程用） 實(shí)驗(yàn)一 苯佐卡因（Benzocaine）的合成 苯佐卡因?yàn)榫植柯樽硭?，外用為撒布劑，用于手術(shù)后創(chuàng)傷止痛、潰瘍痛、一般性癢等。 化學(xué)結(jié)構(gòu)式 化學(xué)名 對(duì)氨基苯甲酸乙酯 性 狀 白色結(jié)晶性粉末，味微苦而麻，熔點(diǎn)88～90℃，易溶于乙醇，極微溶于水。 實(shí)驗(yàn)?zāi)康? 通過苯佐卡因的合成，了解藥物合成的基本過程，掌握酯化反應(yīng)和還原反應(yīng)的原理及基本操作。 實(shí)驗(yàn)原理（主要合成路線）

2、1.還原反應(yīng) 2.酯化反應(yīng) 實(shí)驗(yàn)步驟 1.對(duì)氨基苯甲酸的制備（還原） 稱取4g對(duì)硝基苯甲酸、9g錫粉加入到100ml三頸瓶中，裝上回流冷凝管和滴液漏斗，從漏斗中分批加入20ml濃鹽酸，邊加料邊攪拌，反應(yīng)立即開始（如有必要可用溫火加熱至反應(yīng)發(fā)生）。必要時(shí)可再微熱片刻以保持反應(yīng)正常進(jìn)行，反應(yīng)液中錫粉逐漸減少。當(dāng)反應(yīng)接近終點(diǎn)時(shí)（約30分鐘），反應(yīng)液呈透明狀，稍冷，將反應(yīng)液傾入250ml燒杯中，加少量水消除留存的錫塊固體。反應(yīng)液冷至室溫時(shí)，慢慢滴加濃氨水，邊滴加邊攪拌，使溶液剛好呈堿性。抽濾除去析出的Sn(OH)4沉淀，用少量水洗滌沉淀，合并

3、濾液和洗液（若總體積超過550ml，可在水浴上濃縮）。向?yàn)V液中小心地滴加冰醋酸，有白色固體析出。再滴加少量冰醋酸，有更多的固體析出。用藍(lán)色石蕊試紙檢驗(yàn)到呈酸性為止。在冷水浴上冷卻，過濾得白色固體，晾干后稱重，計(jì)算產(chǎn)率。 2．對(duì)氨基苯甲酸乙酯的制備（酯化） 將自制的2g對(duì)氨基苯甲酸放入干燥的100ml圓底瓶中，加入20ml無水乙醇和2.5ml濃硫酸。振搖使混合均勻，投入沸石，裝上附有氯化鈣干燥管的球形冷凝管，油浴加熱回流60～80分鐘（油浴溫度控制在100～120℃）；稍冷，將反應(yīng)液傾入到85ml水中，在攪拌下，慢慢加入碳酸鈉固體粉末（使碳酸鈉粉末充分溶解），當(dāng)液面有少量白色沉淀出現(xiàn)時(shí)，慢慢

4、加入10%碳酸鈉溶液，將溶液PH值調(diào)至呈中性，抽濾得固體產(chǎn)品，用少量水洗滌固體，抽干，干燥，稱重，計(jì)算產(chǎn)率。 3．對(duì)氨基苯甲酸乙酯的精制 將粗品置于裝有球形冷凝管的100ml圓底瓶中，加入10～15倍（ml/g）50%乙醇，在水浴上加熱溶解。稍冷，加入活性炭脫色（活性炭用量視粗品顏色而定），加熱回流20分鐘，趁熱抽濾。將濾液趁熱轉(zhuǎn)入燒杯中，自然冷卻，待結(jié)晶完全后，抽濾，用少量50%乙醇洗滌兩次，抽干，干燥，稱重，計(jì)算收率。 思考題 1.如何判斷還原反應(yīng)已經(jīng)結(jié)束？為什么？ 2.酯化反應(yīng)為什么需要無水操作？ Experiment 2 SYNTHESIS OF SO

5、DIUM PHENYTOIN Requirement： To master the synthesis technique of sodium phenytoin. To understand coenzyme chemistry,benzoin condensation,oxidation,benzilic acid rearrang- ement and some other reactions.To learn the purification technique of phenytoin sodium. Experiment： 1.Coenzyme Synthesis

6、of Benzoin (i)Materials: thiamine nitrate 2g 0.032mol H2O 4ml 95% ethanol 12ml 3M Na0H 約3.2ml 0.01mol benzaldehyde 8ml 0.079mol (ii)Procedure: Dissolve 2g of thiamine nitrate in about 4ml of water in a 100ml round bottom flask equipped with a

7、 condenser for reflux. Add 12ml of 95% ethanol and cool the solution by swirling the flask in an ice-water bath. Meanwhile, Place about 3.2 ml of 3M sodium hydroxide solution in a small test tube. Cool this solution in the ice bath also. Then, over a period of about 10 minutes,add the cold sodium hy

8、droxide solution to the thiamine solution. Then adjust the solution to pH 8～9 using 10% hydrochloric acid. Measure 8ml of benzaldehyde and add it to the reaction mixture. Then heat the mixture gently on a steam bath at 65℃～70℃ for about 90 minutes. Allow the mixture to cool to room temperature, and

9、then cool the mixture in an ice-water bath. If the product separates as an oil, reheat the mixture until it is once again homogeneous, and then allow it to cool more slowly than before. Scratching of the flask with a glass rod may be required. Collect the product by vacuum filtration using a Buchne

10、r funnel. Wash the product with two 20ml portions of 10% ethano1.Weigh the crude product and then recrystallize it from 95% ethanol. Dry and weigh the product, calculate the percentage yield, and determine its melting point(mp 134℃ to 136℃). Note: (1)The benzaldehyde used for this experiment must

11、 be free of benzoic acid. Benzaldehyde is oxidized easily in air. Don’t expose it to the air too long when taking it. (2)Thiamine is a heat sensitive reagent. It should be stored in a refrigerator when not in use. Since it may decompose on heating, you should take care not to heat the reaction mixt

12、ure too vigorously. Question: (i) Why is sodium hydroxide added to the solution of thiamine nitrate? What is the theoretical quantities of NaOH? What reaction will occur and what compound will produce if we use excess NaOH? (ii)Theoretically, does benzoin have colour? 2、preparation of Benzil

13、 (i)Materials: Benzoin 3g 0.014mol NH4NO3 6.4g 0.08mol CuSO4 0.1g 80% acetic acid 20ml (ii)procedure: Put all the materials in a flask fitted with a reflux condenser, heat to reflux and keep refluxing for 2 hours. Allow to cool to the room temperatur

14、e, a layer of oil forms on the surface. Rub the oil against the wall of the flask with a glass rod or introduce some crystal seed to induce crystallizing. Break the crystal then filter with suction on a Buchner funnel. Wash with water until the washings are neutral. Dry the crystal in infrared light

15、. The yellow crystal can be used directly for the next step. Note: Using TLC to observe the procedure of the reaction. 3. Preparation of phenytoin or phenytoin Sodium (i)Materials benzil 2g 0.009mol 15% NaOH 6ml urea 0.7g 0.0116mol 50% ethanol 10m

16、l (ii)procedure: Equip a flask with a reflux condenser, heat directly,place all materials above sequently in it. Heat gently to reflux, keep refluxing for half an hour until the oil layer (benzil)disappears completely. Pour the reaction mixture into 60ml of cold water, add a small amount of active

17、-carbon, boil for several minutes allow to cool,then filter with suction while hot. Adjust the filtrate to pH 6, phenytoin precipitates. Filter with suction on a Buchner funnel. The solid is dissolved in a solution of 2 ml of 15% NaOH and 20 ml of water, add some active carbon and warm for three min

18、utes with stirring. Filter as fast as possible while hot and wash with a small amount of hot water.Add 6g of NaCl in the filtrate and warm to solve. Allow to cool with stirring, a white crystal (phenytoin sodium) forms. Filter with suction ,press as dry as possible, then dry under reduced pressure.

19、 Identification of phenytoin sodium: 1.The water solution of phenytoin(1:20)is basic to litmus. 2.Take about 0.1g of phenytoin sodium, add 10ml of distilled water, shake to solve, add 0.2ml of HgCl2 test solution, a white precipitate produces which will not solve in an ammonia solution. Note: (i

20、)Keep gentle reflux while refluxing. (ii)During preparing the sodium phenytoin, don’t use too much water or filter repeatedly that will cause the loss of the product considerablly. (iii)The insoluble compound that is filtered off is possibly the product of condensation of one molecule of benzil wi

21、th 2 molecules of urea. Question: (1)Compare the condensation reaction in phenytoin preparation with that in barbitals,give out the common points and the differences. (2)Compare phenytoin sodium with phenobarbitone sodium,bring out the common points and differences of their chemical properties.

22、Reference: (1)Org. React. Vol. IV/269～304 (2)L.F. Fieser: Experiment in Organic Chemistry 170,174(1955) (3)J. Amer. Chem. Soc. 70 3666(1984) (4)王殿翔編:實(shí)用有機(jī)制藥化學(xué)173頁(1954) (5)于燕孫編:制藥化學(xué) 491頁(1963) (6)顧可權(quán)編:重要有機(jī)反應(yīng)及其應(yīng)用 6頁(二苯羥乙酸重排) 64頁(安息香縮合)(1958) Experiment 3

23、 SYNTHESIS OF PHENYTOIN-Zn 1、Main reaction: 2、Material: Phenytoin 0.5g NH3.H2O 15ml ZnSO4 0.3g 3、Procedure: Weigh 0.5g of phenytoin precipitates and place them in a 50ml beaker, then add ammonia solution (15ml NH3.H2O + 10ml H2O).The

24、solid is dissolved in ammonia solution. Meanwhile, dissolve 0.3g of ZnSO4 in about 3ml water, then add them to phenytoin ammonia solution. A white crystal (phenytoin-Zn)forms. Filter with suction on a Buchner funnel. Wash the product with a small amount water, press as dry as possible. Dry and weigh

25、 the product. Calculate the percentage. Question: Why can not use directly phenytoin-Na react with ZnSO4 to prepare phenytoin-Zn? Experiment 4 THE PREPARATION OF SULFACETAMIDE 1.The purposes: (1)Learn the basic principles of acetylation, and how to control the operation conditio

26、ns (including PH and temperature) in order that the desired product is the main one. (2)According to physical and chemical properties to separate and purify the product from a mixture. 2. Main reaction: 3. Material: Name moles ratio of mole weight or volume sulfanilamide 0.05 1.0

27、 8.6g acetic anhydride 0.071 1.42 6.8ml 22.5% NaOH 77% 40% 0.055 0.094 1.12 1.9 11.5ml 5ml 4.Procedure: In a 100ml three-neck flask equipped with a stirrer and a thermometer, place 8.6g of sulfanilamide and 11.5ml of 22.5% sodium hydroxide solution. Stir and

28、heat the mixture to 50 ℃～55℃ on a hot-water bath. After the solid has dissolved, add about one fourth of 77% sodium hydroxide solution and acetic anhydride per five minutes. Keep the temperature at 50℃～55℃ and continue stirring the contents of reaction flask for 30 minutes. When the reaction has co

29、mpleted, pour the mixture into a 50ml beaker and add 10ml water, then neutralize to pH 7 with 1:1 hydrochloric acid(about 3ml).Cool the mixture in an ice bath for 1～2 hours, during this period a precipitate produces. Filter the mixture by suction through a Buchner funnel and acidify the filtrate to

30、 pH 5～4 with 1:1 hydrochloric acid. Cool the mixture in an ice bath for 15 minutes, collect the solid by suction filtration. Add 10% hydrochloric acid solution (which is three times as many as the solid) to the solid while stirring with a glass rod, then let the mixture stand for 30 minutes. Filt

31、er the mixture to remove the solid. Add a small amount of decolorizing carbon into the filtered solution and swirl at room temperature. Filter the mixture by suction filtration, and neutralize the filtrate to pH 5 with a solution of 40% sodium hydroxide while stirring, during which time the SA shou

32、ld begin to crystallize from the solution. Filter the product by suction until the product is free of solvent. Dry and weigh the product. Determine its melting point(178℃～182℃)and calculate the percentage. If its melting point can’t pass, recrystallize the product from warm water using 15ml/g of

33、product. Questions: 1) What properties have the sulfanilamides? 2) During the operating procedure, what is the product precipitated at pH 7? What is the product precipitated at pH 5? In 10% hydrochloric acid solution, what is the soluble material? What is the insoluble material? Why?

34、3)During the procedure of the reaction, if the basicity is too strong, it will result in more SN, middle SA and less diacety1-SN,if the basicity is too weak, it will result in more diacety1-SN,middle SA and less SN. Why? Experiment 5 SYNTHESIS OF CINAMETIC ACID 1. Purpose

35、: To understand Williamson synthesis and Knoevenagel reaction. 2. Main Reaction: 3. Procedure: (1)Synthesis of 3-methoxy-4-(2-hydroxyethoxy)-benzaldehyde. Materials: Vanillin 9.1 g 0.06mol HOCH2CH2C1 9.6 ml 0.143mol NaOH 5.7 g 0.143mol H2O

36、 30 ml KI 1.2 g 0.0077mol In a 100ml three-neck flask equipped with a stirrer,a thermometer and a dropping funnel, place 9.1g of vanillin,1.2g of KI and NaOH solution. Stir and heat the mixture to 70℃ on a hot-water bath, then add HOCH2CH2C1 gently with dropping funnel(abou

37、t 45 minutes finished).Rearrange dropping funnel for a reflux condenser. Stir and keep the mixture at 75℃～85℃ for 4～5 hours. When the reaction is finished, place the mixture into a refrigerator until the precipitate forms completely. Filter with suction and wash the product with ice-water until the

38、washings are neutral. Dry the crystal in infrared light, weigh and calculate the yield. (2)Preparation of 3-[4-(2-hydroxyethoxy)-3-methoxy-phenyl]-2-propenoic acid Materials: 3-methoxy-4-(2-Hydroxyethoxy)-benzaldehyde 3.92g 0.02mol Malonic acid 2.5g 0

39、.024mol Pyridine 20 ml Piperidine 8 drops In a 100ml three-neck flask equipped with a stirrer, a thermometer and a reflux condenser, place 2.5g of malonic acid, 20ml of pyridine. Stir the mixture, after the solid dissolved,

40、add 3.92g of 3-methoxy-4-(2-hydroxyethoxy)-benzaldehyde and piperidine. Stir and keep the mixture at 80℃～100℃ for 2 hrs. When reaction is finished, pour the mixture slowly into beaker containing ice and 20ml of conc.HC1 with stirring. Cool the mixture in an ice bath until the precipitates complete.

41、Filterring and washing gives a grey product, which is then dried under infrared light and weighted. Calculate the yield and determine the melting point. Reference: (1)CA 54:16428i (2)CA 68:77977k (3)Handbook of Practical Organic Chemistry P159 (4)Vogel: Practical Organic Chemistry 802(1978)

42、 實(shí)驗(yàn)六 簿層色譜（TLC法） 一、實(shí)驗(yàn)?zāi)康暮突疽? 薄層色譜又叫薄板層析，是色譜法中的一種，是快速分離和定性分析少量物質(zhì)的一種很重要的實(shí)驗(yàn)技術(shù)，屬固-液吸附色譜，它兼?zhèn)淞酥V和紙色譜的優(yōu)點(diǎn)，一方面適用于少量樣品（幾微克，甚至0.01微克）的分離；另一方面在制作薄層板時(shí)，把吸附層加厚加大，因此，又可用來精制樣品，此法特別適用于揮發(fā)性較小或較高溫度易發(fā)生變化而不能用氣相色譜分析的物質(zhì)。此外，薄層色譜法還可用來跟蹤有機(jī)反應(yīng)及進(jìn)行柱色譜之前的一種“預(yù)試”。 通過實(shí)驗(yàn)對(duì)學(xué)生做以下要求： （1）初步掌握簿層色譜法的實(shí)驗(yàn)技術(shù)。 （2）學(xué)

43、會(huì)用薄層色譜法來跟蹤有機(jī)反應(yīng)。 二、基本原理 這是利用吸附劑（硅膠、氧化鋁等）對(duì)不同組分吸附能力的差異從而達(dá)到分離目的的方法。 三、操作要點(diǎn)和說明 薄層色譜法的整個(gè)過程包括以下步驟： 1、薄層板的制備 制薄層板的主要原料是吸附劑和粘結(jié)劑 吸附劑：最常用于TLC的吸附劑為硅膠 GF254； 硅膠HF254。 粘結(jié)劑：一般用所羧甲基纖維素鈉（CMC-Na），也有用淀粉的。CMC-Na為粉狀固體，用時(shí)先加水，水浴上熬成糊狀，配成1％水溶液。 制板：（1）小板的制備：將硅膠加1％CMC-Na，調(diào)成漿狀（在平鋪玻璃板上能晃動(dòng)但不能流動(dòng)），將其涂在載玻片上（75mm×25mm），為

44、使其坦平，可將載玻片用手端平晃動(dòng)，致坦平為止，放在干凈平坦的臺(tái)面上，晾干之后放入110℃烘箱活化1小時(shí)即可使用（一次可做很多塊）。 （2）大板的制備：板的厚度增加到0.5～1mm，其寬度、塊數(shù)根據(jù)樣品量而定，一般分離樣品量在10～50mg，樣品的濃度一般為5%～10%，制備過程同小板的制備。 2、點(diǎn)樣 點(diǎn)樣用的毛細(xì)管為內(nèi)徑＜lmm的管口平整的毛細(xì)管，將樣品溶于低沸點(diǎn)的溶劑（乙醚、丙酮、乙醇、四氫呋喃等）配成1％溶液。 點(diǎn)樣前，可先用鉛筆在小板上距一端5mm處輕輕劃一橫線，作為起始線，然后用毛細(xì)管吸取樣品在起始線上小心點(diǎn)樣，如需重復(fù)點(diǎn)樣，則應(yīng)待前次點(diǎn)樣的溶劑揮發(fā)后方可重點(diǎn)。若在同一塊板上點(diǎn)

45、幾個(gè)樣，樣品點(diǎn)間距離為5mm以上。 3、展開 展開劑的選擇主要根據(jù)樣品的極性、溶解度和吸附劑的活性等因素來考慮。 薄層的展開在密閉的容器中進(jìn)行。先將選擇的展開劑放入色譜器中（小板可用廣口瓶代替），使色譜器內(nèi)空氣飽和5－10min，再將點(diǎn)好試樣的薄層板放入色譜器中進(jìn)行展開，點(diǎn)樣的位置必須在展開劑液面之上，當(dāng)展開劑上升到薄層的前沿（離前端 5－10mm）或多組分已明顯分開時(shí)，取出薄層板放平晾干，用鉛筆劃溶劑前沿的位置后，即可顯色。 4、顯色 如果化合物本身有顏色，就可直接觀察它的斑點(diǎn)。如果本身無色，可先在紫外燈光下觀察有無熒光斑點(diǎn)（一般含有共軛雙鍵的物質(zhì)都有），用鉛筆在薄層板上劃出斑點(diǎn)的位置

46、；對(duì)于在紫外燈光下不顯色的，可放在含少量碘蒸氣的容器中顯色來檢查色點(diǎn)（因?yàn)樵S多化合物都能和碘成黃棕色斑點(diǎn)），顯色后，立即用鉛筆標(biāo)出斑點(diǎn)的位置。 5、用TLC跟蹤有機(jī)反應(yīng) 在同一塊板上點(diǎn)上原料樣和反應(yīng)混合物樣（均需配成稀溶液），按上述方法進(jìn)行展開和顯色，記下原料樣的斑點(diǎn)位置和反應(yīng)混合物樣中相應(yīng)斑點(diǎn)的位置和大小。過一定時(shí)間后，再取反應(yīng)混合物樣液點(diǎn)樣、展開、顯色，如發(fā)現(xiàn)反應(yīng)混合液樣中相應(yīng)于原料斑點(diǎn)的位置處，無斑點(diǎn)或斑點(diǎn)變小，則說明反應(yīng)已經(jīng)完成或接近完成，所以依此可跟蹤有機(jī)化學(xué)反應(yīng)。這在有機(jī)合成上很有意義。 6、用TLC分離、純化混合物 當(dāng)反應(yīng)產(chǎn)物量很少或尚未有很好的分離方法時(shí)，也需經(jīng)過制備性薄層

47、色譜來分離或純化，制備性薄層色譜與鑒定用的薄層色譜基本操作相似，待樣品展開后，按色帶刮下帶有樣品的吸附劑，分別洗脫。 四、思考題 1、在一定的操作條件下為什么可利用Rf值來鑒定化合物？ 2、在混合物薄層色譜中，如何判定各組分在薄層上的位置？ 3、展開劑的高度若超過了點(diǎn)樣線，對(duì)薄層色譜有何影響？ 實(shí)驗(yàn)七 鎮(zhèn)痛藥散利痛、百服寧和泰諾林中有效成分的分離制備及分析 一、實(shí)驗(yàn)?zāi)康? 1、了解薄層色譜法的原理及其應(yīng)用。 2、掌握定性薄層色譜及制備薄層色譜的實(shí)驗(yàn)操作技術(shù)。 3、了解對(duì)多組分混合物中各組分進(jìn)行分別鑒定的一般方法。 二、實(shí)驗(yàn)原理 由于鎮(zhèn)痛藥中不同成分結(jié)構(gòu)不同

48、，吸附劑對(duì)各成分的吸附能力不同，在展開劑作用下，它們發(fā)生解析的速度不同，從而得以分離。通過比較樣品斑點(diǎn)與純組分的Rf值，初步確定藥物中各成分的化學(xué)組成，然后可用制備薄層色譜來分離各組分。市售散利痛片劑中含撲熱息痛(250mg)，異丙安替吡啉(150mg)及咖啡因(50mg)。百服寧片劑中含撲熱息痛(500mg)，咖啡因(65mg)。泰諾林片劑中含撲熱息痛(500mg)。本實(shí)驗(yàn)將市售解熱鎮(zhèn)痛藥散利痛或百服寧或泰諾林片劑用二氯甲烷萃取得到的提取液，以乙酸乙酯為展開劑，通過三用紫外燈顯色來分析解熱鎮(zhèn)痛藥中各組分。同時(shí)將市售百服寧片劑用CH2Cl2萃取，得到的提取濃縮液，通過制備薄層色譜分離各成分。

49、 撲熱息痛 異丙安替吡啉 咖啡因 三、儀器和藥品 1、儀器 三用紫外分析儀 小漏斗 廣口瓶 層析缸(20×10cm) 毛細(xì)管 研缽 滴管 薄層板(3×8cm，20×10cm) 研缽 鋼勺 刮刀 O.6％CMC-Na 鉛筆 尺子 小玻璃柱 100、250ml三角燒瓶 2、藥品 市售散利痛 市售百服寧 市售泰諾林 硅膠GF254 硅膠板 二氯甲烷 乙酸乙酯 石油醚 棉花或小濾紙 1％對(duì)乙酰氨基酚的二氯甲烷溶液 2％咖啡

50、因的二氯甲烷溶液 2％ 4-異丙基安替吡啉的二氯甲烷溶液 四、實(shí)驗(yàn)步驟 1、樣品液的制備 領(lǐng)取l～2顆市售百服寧藥片，研成粉狀，加40mL二氯甲烷攪拌lO分鐘過濾，濾液收集于小試管中，用于薄層點(diǎn)樣。 2、點(diǎn)樣 取三塊3×8cm薄層板，分別在距一端lcm處用鉛筆輕輕畫一條橫線為起始線。用毛細(xì)管在一塊薄層板上點(diǎn)藥品提取液和2％對(duì)乙酰氨基酚的二氯甲烷溶液，第二塊板上點(diǎn)藥品提取液和2％咖啡因的二氯甲烷溶液。點(diǎn)樣品間距1cm，如果樣點(diǎn)顏色太淺，可重復(fù)點(diǎn)樣，但必須待前次樣點(diǎn)干燥后進(jìn)行，點(diǎn)樣原點(diǎn)不易過大。 3、展開 用乙酸乙酯(或乙酸乙酯：石油醚=3：1)為展開劑。待樣

51、點(diǎn)干燥后，小心地將薄層板放入己加入展開劑(8mL)的125 mL廣口瓶中進(jìn)行展開，蓋好瓶蓋，觀察展開劑前沿上升至離板的上端的1cm取出，盡快用鉛筆在展開劑上升的前沿劃一記號(hào)。 4、鑒定 待溶劑揮發(fā)干后，將薄層板放在紫外燈下觀察，可清晰地看到兩個(gè)粉紅色斑點(diǎn)，用鉛筆繞亮點(diǎn)作出記號(hào)，計(jì)算各個(gè)位移斑點(diǎn)的Rf值，并將未知物與標(biāo)準(zhǔn)樣品比較。 領(lǐng)取l一2顆散利痛藥片，泰諾林藥片，分別研成粉末，按以上方法操作，計(jì)算各個(gè)位移斑點(diǎn)的Rf值，并將未知物與標(biāo)準(zhǔn)樣品比較。 取20×20cm薄層板，在距底線1.5cm處用藥品提取液(經(jīng)濃縮)點(diǎn)上一條連續(xù)線，帶溶劑揮發(fā)后用上述展開劑展開然后在紫外燈下顯色，并將各成分色帶切刮下來，分別用二氯甲烷提取。提取液蒸去劑后即得各組分的純品，進(jìn)行TLC檢識(shí)，確定成分。 五、思考題 1、分離有機(jī)化合物的常用實(shí)驗(yàn)技術(shù)有哪些? 2、鑒定有機(jī)化合物的方法有哪些? 3、薄層色譜的用途有哪些? 15