酰胺的合成-060123.doc

经典合成反应标准操作 酰胺化反应 药明康德新药开发有限公司经典化学合成反应标准操作酰胺及酰亚胺的合成编者：齐志奇药明康德新药开发有限公司化学合成部目 录1. 前言32. 羧酸与胺的缩合酰化反应32.1活性酯法32.1.1应用氯甲酸乙酯或异丁酯活性酯法合成酰胺示例52.1.2应用氯甲酸乙酯或异丁酯活性酯法合成伯酰胺示例52.1.3应用羰基二咪唑合成Weinreb酰胺示例62.1.4应用的磺酰氯合成酰胺示例62.1.5应用Boc酸酐合成伯酰胺示例72.2碳二亚胺类缩合剂法72.2.1应用DCC缩合法合成酰胺示例92.2.2应用DIC缩合法合成酰胺示例102.2.3应用EDC缩合法合成酰胺示例一 （二氯甲烷为溶剂）102.2.4应用EDC缩合法合成酰胺示例二 （DMF为溶剂）112.3 鎓盐类的缩合剂法112.3.1应用HATU/TBTU为缩合剂合成酰胺示例132.3.2应用BOP为缩合剂合成酰胺示例142.3.3应用PyBOP为缩合剂合成酰胺示例一 （常规）142.3.4应用PyBOP为缩合剂合成酰胺示例二（用于合成伯酰胺）152.4 有机磷类缩合剂152.4.1应用DPP-Cl为缩合剂合成酰胺示例162.4.2应用DPPA为缩合剂合成酰胺示例162.4.3应用BOP-Cl为缩合剂合成酰胺示例172.5.1应用三苯基磷-多卤代甲烷合成酰胺示例182.5.2应用三苯基磷-六氯丙酮合成酰胺示例182.5.3应用三苯基磷-NBS合成酰胺示例193. 氨或胺与酰卤的酰化反应193.1酰卤的制备示例203.5.1应用二氯亚砜合成酰氯示例203.5.2用草酰氯合成酰氯示例213.5.3用三氯均三嗪合成酰氯示例213.5.4用三氟均三嗪合成酰氟示例223.1应用酰卤的合成酰胺223.5.1应用酰氯合成酰胺示例（有机碱）223.5.2应用酰氯合成酰胺示例（无机碱）223.5.3应用酰氟合成酰胺示例244. 氨或胺与酸酐的酰化反应244.2酸酐合成酰胺示例255. 其他缩合方法251. 前言酰胺化是有机合成中最基本，也是最重要的合成方法之一。 合成酰胺的通用方法是先活化羧基，然后再与胺反应得到酰胺。 2. 羧酸与胺的缩合酰化反应羧酸与胺的反应是合成酰胺的重要方法。 由于这一反应是一个平衡反应，因此采用过量的反应物之一或除去反应中生成的水， 均有利于平衡向产物方向转移。 除去水的方法通常是在反应物中加入苯或甲苯进行共沸蒸馏。 例如将a-羟基乙酸及苄胺于90共热， 并蒸出生成的水及过量的苄胺，则生成a-羟基乙酰基苄胺 Rivera L S Z, Darrillo L, Mancilla T. Org. Prep. Proc. Int. 2000, 32 (1), 295。2.1活性酯法活性酯法早期主要应用酸与氯甲酸乙酯或异丁酯反应生成混合酸酐，而后再与胺反应得到相应的酰胺，这一反应如果酸的a-位位阻大或者连有吸电子基团，有时会停留在混合酸酐这一步，但加热可以促使其反应；这一反应也可用于无取代酰胺的合成 J. Med. Chem. 1968, 11, 534。应用羰基二咪唑(CDI)与羧酸反应得到活性较高的酰基咪唑，许多酰基咪唑有一定的稳定性，有时可以分离出来，但一般来说其不用分离，反应液直接与胺一锅反应制备相应的酰胺；有文献报道羰基二咪唑与三氟甲磺酸甲酯反应得到的二甲基化的三氟甲磺酸盐(CBMIT)的缩合性能更好。该类反应由于过量的CDI或CBMIT会和胺反应得到脲的副产物，因此其用量一定要严格控制在1当量。最近我们发现应用CDI合成Weinreb 酰胺是一个较好的方法。另一类常用的方法是羧酸和磺酰氯生成羧酸-磺酸的混合酸酐，其与胺反应得到相应的酰胺。常用的磺酰氯有甲烷磺酰氯（MsCl），对甲苯磺酰氯（TsCl）和对硝基苯磺酰氯（NsCl）, 对硝基苯磺酰氯由于其吸电子性，其与酸反应生成活性更高的混合酸酐，一般二级胺和三级胺，甚至位阻很大的胺都能顺利反应 Lee J.C., Cho Y. H., Lee H. K., et al. Synth. Commnun. 1995, 25 (18), 2877.。 通过酸与Boc酸酐反应得到的混合酸酐与氨反应可得到相应的伯酰胺。上述的这些缩合方法一般都是分步进行，其主要因为胺极易与这些活性酯反应得到相应的酰化产物。2.1.1应用氯甲酸乙酯或异丁酯活性酯法合成酰胺示例A solution of acid 1 and 4-methylmorpholine (NMM, 0.54 mL, 4.92 mmol) in DMF (10 mL) was treated at room temperature with isobutyl chloroformate (0.64 mL, 4.92 mmol). After 30 min, pentylamine (0.57 mL, 4.92 mmol) was added. The reaction mixture was stirred for 12 h. The solvent was evaporated, and the residue was partitioned between ethyl acetate (25 mL) and water (25 mL). The ethyl acetate layer was washed with 5% NaHCO3 (10 mL) and brine (20 mL), dried over Na2SO4, and evaporated. The residue was chromatographed on silica gel eluting with hexane and ethyl acetate (2:1) to give 0.33 g (33%) of tert-butoxycarbonylated amino amide (2). 2.1.2应用氯甲酸乙酯或异丁酯活性酯法合成伯酰胺示例To a cooled (-20) solution of compound 3 (4.8 g, 18 mmol) in anhydrous THF (50 mL) was added Et3N (2.5 mL, 18 mmol) during 20 min. After 10 min ethyl chloroformate (1.7 mL, 18mmol) was added at the same temperature during 10 min and stirred for an additional 20 min. The resulting mixture was saturated with NH3 gas and kept at r.t. overnight. The mixture was concentrated at reduced pressure, the residue was diluted with H2O (10 mL) and extracted with EtOAc (4 *10 mL). The combined organic phases were dried (Na2SO4), filtered and concentrated to afford a white solid. It was recrystallized from petroleum ether and ethyl acetate to afford pure product 4 as white crystal (3.1 g, 65%). 2.1.3应用羰基二咪唑合成Weinreb酰胺示例 Neil K. Garg, Daniel D. Caspi, and Brian M. Stoltz. J. Am. Chem. Soc. 2004, 126, 9552.To acid 5 (4.0 g, 14.1 mmol) in CH2Cl2 (70 mL) at 23 was added 1, 1-carbonyldiimidazole (3.65 g, 22.5 mmol) in equal portions over 15 min. After the final addition, stirring was continued for 10 min, then N,O-dimethylhydroxylamine HCl (3.43 g, 35.16 mmol) was added in one portion. The reaction was allowed to stir at 23 for 3 h. Et2O was added (50 mL) and the reaction mixture was filtered. The filtrate was evaporated, diluted with Et2O (125 mL), washed with 5% aq. citric acid (2 x 50 mL) and brine (50 mL), and dried over MgSO4. The crude product was purified by flash chromatography (3:1 hexanes: EtOAc) to afford Weinreb amide 6 (4.29 g, 93% yield) as a colorless oil. Rf 0.42 (2:1 hexanes:EtOAc); 1H NMR (300 MHz, CDCl3): 5.43 (m, 1H), 4.72 (s, 1H), 4.17-4.11 (m, 1H), 3.71 (s, 3H), 3.22 (s, 3H), 2.59-2.24 (comp. m, 3H), 2.03 (dd, J = 14.6 Hz, 4.1 Hz, 1H), 1.75-1.71 (m, 3H), 0.86 (s, 9H), 0.11 (s, 3H), 0.09 (s, 3H).2.1.4应用的磺酰氯合成酰胺示例A mixture of the benzoic acid (10 mmol), 4-methylbenzene-1-sulfonyl chloride (10 mmol), K2CO3 (5.52 g, 40 mmol) and TEBAC (0.23 g, 1mmol) in 60 mL of benzene is stirred at reflux for 40 min. Then ethyl 2-aminoacetate (10 mmol) is added and stirring is continued for 10 min at reflux temperature. The precipitate is filtered off, and the filtrate is evaporated under reduced pressure. The carboxamide 8 thus obtained is crystallized from MeOH to afford the pure product (yield 82%). 2.1.5应用Boc酸酐合成伯酰胺示例Typical procedure: To a stirred solution of N-protected amino acid 9 (10 mmol), pyridine (0.5 ml) and Boc2O (3 g, 13 mmol) in an appropriate solvent (such as dioxane, DMF and CH3CN, 10-15 ml), ammonium hydrogencarbonate (1 g, 12.6 mmol) was added and the mixture was stirred for 4-16 h. Ethyl acetate was added and after washings with water and 5% H2SO4, the solution was dried, the solvent was evaporated and the product was triturated with ether. In another variant the reaction mixture was diluted with water (30-40 ml), stirred until crystallization was completed, a residue was then collected by filtration, washed by water, dried and recrystallized as necessary.2.2碳二亚胺类缩合剂法利用碳二亚胺类缩合剂缩合制备酰胺在药物合成中应用极为广泛，目前常用的缩合剂主要有三种：二环己基碳二亚胺(DCC)、二异丙基碳二亚胺(DIC)和1-(3-二甲胺基丙基)-3-乙基碳二亚胺(EDCI)。使用该类的缩合剂一般需要加入酰化催化剂或活化剂，如4-N,N-二甲基吡啶（DMAP）、1-羟基苯并三氮唑(HOBt)等等，其主要由于在反应的第一阶段酸对碳二亚胺的加成中间体其并不稳定，若不用酰化催化剂转化为相应的活性酯或活性酰胺，其自身会通过重排成相应的稳定的脲的副产物 (Path b).常用的缩合活化剂有以下几种，目前4-N,N-二甲基吡啶（DMAP）已被广泛应用于催化各种酰化反应。有时在用DMAP催化效果不好时，可采用4-PPY，据相关文献报道其催化能力要比DMAP高千倍左右。在三个常用的缩合剂DCC、DIC和EDCI中， DCC和DIC的价格较为便宜，一般DCC和DMAP合用，使用DCC有一个最大的缺点就是反应的另一产物二环己基脲在一般的有机相溶解度很小但又都有一些微溶，因此通过一些常用的纯化方法，重结晶，柱层析等等很难将其除得很彻底；由于二环己基脲在乙醚中的溶解度相对要比其他溶剂小， 因此处理这类反应一般蒸掉反应溶剂后加入乙醚，滤掉大部分的二环己基脲后再进一步处理。DIC由于其产生的二异丙基脲在有一般的有机溶剂中溶解度较好，因此一般在组合化学的固相合成中用的较多。目前，在药物化学中用的最多的还是EDCI，其一个主要的特点就是其反应后的生成的脲是水溶性的，很容易被洗掉，一般EDCI与HOBt合用（注意: 这一反应HOBt一般是缺不了的，否则有可能导致缩合产率太低）。有时如果酸的a-位位阻大或者连有吸电子基团，反应会停留在活性酯这一步（这一活性酯的质谱信号较强，可通过MS或LC-MS检测到）。由于HOBt也是水溶性的，其使得反应的处理和纯化相对要容易。一般在这一缩合中要加入碱，特别当用胺或氨基酸的盐酸盐等缩合，常用的是加2-3当量的N-甲基吗啡啉或二异丙基乙胺（DIEA, Hunig base）, 缩合时以二氯甲烷为溶剂，若底物的溶解度不好，可用DMF作反应溶剂，再使用该方法进行。在使用该方法进行氨基酸缩合时，一般投料必须在零下2030下进行，并在此温度下搅拌近一小时后再室温搅拌，否则其会引起氨基酸的消旋化。2.2.1应用DCC缩合法合成酰胺示例To a solution of compound 11 (4.06 g, 10 mmol) in DMF (150 mL) was added N-hydroxybenzotriazole (HOBt, 5.64 g, 42 mmol), followed by dicyclohexylcarbodiimide (DCC; 8.60 g, 42 mmol). After stirring for l h, a solution of di-tert-butyl 4-amino-4-2-(tert-butoxycarbonyl)ethylheptanedioate 5 (17.34 g, 41.7 mmol) in DMF (60 mL) was added and the solution stirred at 25 for 23 h. The crystals were filtered and washed on the filter with DMF (25 mL). The solvent was distilled at 50/1mm, and the residual oil was dissolved in ether (600 mL). Crystals were filtered, the ethereal solution was washed successively with 10% HCl (2 x100 mL), saturated NaHCO3 (2 x 100 mL), and brine (2 x 50 mL), then dried (Na2SO4). The ether solution was filtered through celite and solvent was then removed in vacuo to afford 19.0 g of crude product, which was purified on a silica column eluting with toluene/EtOAc (1:1) to furnish (60%) the white, non-crystalline ester 12: 14.0 g; mp 55-60. 1H NMR 1.43 (s, CH3, 108H), 1.94-2.28 (m, CH2CH2, 64H), 5.87 (s, NH, 4H), 6.17 (s, CH=CH, 2H); 13C NMR (DMSO-d6) 28.3 (CH3), 29.3 (CH2CH2), 56.8 (CNH), 69.0 (CSO2), 171.1 (CO), 171.4 (CO). 2.2.2应用DIC缩合法合成酰胺示例To a solution of amine 13 (106 mg, 0.3 mmol), Fmoc-Phe-OH (116 mg, 0.3 mmol), and HOBt (44.8 mg, 0.33 mmol) in anhydrous DMF (2 mL) was added DIC (56 L, 0.36 mmol). The resulting mixture was stirred at room temperature overnight, and DMF was then evaporated under high vacuum. The residue was dissolved in ethyl acetate (10 mL), washed sequentially with saturated aqueous NaHCO3 and brine, and then dried over Na2SO4. The evaporation of the solvent gave the crude product that was directly submitted for the Fmoc removal without purification. The crude product was dissolved in DMF (8 mL), piperidine (2.0 mL) was added, and the resulting solution was stirred at room temperature for 1 h. Following the solvent evaporation, the residue was purified by silica gel chromatography (50% ethyl acetate in hexanes to 10% methanol in chloroform) to provide product 14 (128 mg) in 85% yield as a mixture of two diastereomers. 1H NMR (CDCl3, 400 MHz) 8.12-8.00 (2H, m), 7.90-7.80 (2H, m), 7.70-7.54 (2H, m), 7.42 (2H, m), 7.35-7.20 (2H, m), 6.97-6.83 (3H, m), 5.32 (1H, m), 4.32 (1H, m), 4.20-4.03 (2H, m), 3.96-3.80 (2H, m), 3.60 (1H, m), 2.98 (3H, m), 2.88 (2H, s), 2.60 (1H, s), 2.00 (1H, m), 1.85 (2H, m), 1.77-1.55 (3H, m); MS (ES+) m/z ) 501.4 (M + 1).2.2.3应用EDC缩合法合成酰胺示例一 （二氯甲烷为溶剂）To a solution of amine16 (0.284 mg, 1.19 mmol) and 5-hexenoic acid 15(0.136 g, 1.19 mmol) in CH2Cl2 (12.0 ml) at 0 were added HOBt (0.177 g, 1.31 mmol) and EDC (0.251 g, 1.31 mmol). The reaction mixture was stirred at room temperature for 10 h, then washed with 5% aqueous HCl (315.0 ml), 5% aqueous NaHCO3 (20 .0 ml), H2O (20.0 ml), and brine (20.0 ml), and dried (Na2SO4). Purification by flash chromatography (CH3Cl/MeOH, 10%, Rf = 0.43) afforded amidoalkene 17 in 99% yield as a brown oil. 2.2.4应用EDC缩合法合成酰胺示例二 （DMF为溶剂）A DMF solution (10 mL) containing HOBt (103 mg, 0.76 mmol), EDC (192 mg, 1.0 mmol), and Boc-D-Ile (172 mg, 0.76 mmol) was stirred at room temperature for 20 h. A solution of the amino ketal 18 (0.41 g, 0.76 mmol) and 4-methylmorpholine (0.17 mL, 1.5 mmol) dissolved in 10 mL of DMF was then added to the reaction mixture. After 4 h the reaction mixture was partitioned between EtOAc and H2O. The organic layer was washed with H2O, dried over MgSO4, and concentrated under reduced pressure. Flash chromatography (4:1 EtOAc/hexanes) afforded the Boc ketal 19 (0.44 g, 0.59 mmol, 78%). 2.3 鎓盐类的缩合剂法近年来，许多盐缩合剂被相继开发出来用于酰胺的缩合反应，从盐的种类来分，主要有两类，一类是碳鎓盐，目前常用的为O-(7-氮杂苯并三氮唑-1-基)-二（二甲胺基）碳鎓六氟磷酸盐（HATU）、O-（苯并三氮唑-1-基)-二（二甲胺基）碳鎓六氟磷酸盐 （HBTU）、O-(5-氯苯并三氮唑-1-基)-二（二甲胺基）碳鎓六氟磷酸盐（HCTU）、O-（苯并三氮唑-1-基)-二（二甲胺基）碳鎓四氟硼酸盐（TBTU）、O-(N-丁二酰亚胺基)-二（二甲胺基）碳鎓四氟硼酸盐（TSTU）、O-(N-endo-5-降莰烯-2,3-二碳二酰亚胺)-二（二甲胺基）碳鎓四氟硼酸盐（TNTU）等。这些试剂性能及应用有一些区别：HATU 是活性最高的碳鎓盐类缩合剂，但由于它价格昂贵很少用于工业化生产，而且经常是在其它缩合剂效果不好时才用到它。 HBTU 相对来说要经济的多，而且可以用于大多数缩合反应，然而其利较低的收率是限制用于大量生产的主要原因。HCTU活性较高，可以代替HATU用于工业化生产，其高活性要归功于有更好活性的Cl-HOBt 中间体。 TSTU 和 TNTU 可以用于含水溶剂的酰胺化反应。若将HATU和HBTU的二甲胺基变为四氢吡咯基可以得到活性比它们更高的O-(7-氮杂苯并三氮唑-1-基)-二（四氢吡咯基）碳鎓六氟磷酸盐（HAPyU）、O-（苯并三氮唑-1-基)-二（四氢吡咯基）碳鎓六氟磷酸盐（HBPyU）,但这些试剂的价格极其昂贵。另一类为鏻鎓盐，最早的为苯并三氮唑-1-基氧-三（二甲胺基）鏻鎓六氟磷酸盐 （BOP）试剂，该试剂由于产生致癌的六甲基磷酰胺（HMPA）副产物，因而近年来被活性更好的，不产生致癌的副产物的苯并三氮唑-1-基氧-三（四氢吡咯基）鏻鎓六氟磷酸盐 （PyBOP）所代替。在鏻鎓盐类的缩合剂中PyBOP的是一个较为强的缩合剂，一般其他缩合剂缩合不好时常常用PyBOP可以得到更好的结果。比如PyBOP可用于将氨基酸与氯化铵缩合得到相应的氨基酰胺 J. Med. Chem.; EN; 43; 15; 2000; 2860 - 2870.。最近有报道PyAOP的缩合剂具有更强的活性。使用碳鎓盐缩合剂进行酰胺缩合，主要是通过分子内的转移，一步得到相应的活性酯，以下以HATU的缩合反应为例，说明其反应机理。2.3.1应用HATU/TBTU为缩合剂合成酰胺示例The general procedure:The carboxyl acid (10mmol), amine (10.4 mmol) and triethylamine (20 mmol) are dissolved in MeCN (20 mL), and HBTU or HATU (10.4mmol) is added to the solution. After 15-30min the reaction is completed. 100-200 mL of a saturated NaCl solution is then added and the product extracted with EtOAc (350 mL). The combined organics are washed with 2N HCl, H2O, 5% NaHCO3, and then H2O. The organics are dried over MgSO4, filtered, and concentrated in vacuo to give the amide (90-100% yield).2.3.2 应用BOP为缩合剂合成酰胺示例A solution of tert-butyloxycarbonyl threonine 20 (2.19 g, 10 mmol) and phenylalanine methyl ester hydrochloride 21 (2.16 g, 10 mmol) in 150 mL CH3CN is stirred at R.T. while the BOP-reagent (4.42 g, 10 mmol) is added, followed by the addition of triethylamine (2.2 g, 2.8 mL, 20 mmol). The reaction is stirred at R.T. for 1.5 hr. 100 mL of a saturated NaCl solution is added and the product extracted with EtOAc. The combined organics are washed with 2N HCl, H2O, 5% NaHCO3, and then H2O. The organics are dried over MgSO4, filtered, and concentrated in vacuo to give the dipeptide (3.74g, 98%).2.3.3应用PyBOP为缩合剂合成酰胺示例一 （常规）Morpholine(0.17 mL, 0.58 mmol) and PyBOP (0.56 g, 0.32 mmol) were added to the solution of N-methylmorpholine (0.22 mL, 0.58 mmol) and carboxylic acid 23 (0.50 g, 0.29 mmol) in dimethylformamide (5 mL). The mixture was stirred at room temperature for 3 days. The mixture was quenched with water and the aqueous solution was extracted with dichloromethane. The organic layer was washed with water, dried over Na2SO4 and concentrated in vacuo. The crude product was purified by silica gel column chromatography eluting with dichloromethane/ethanol (9/1) to give morpholide 24 as a white solid (109 mg, 65%). Mp 9294. 1H NMR d 7.56 (s, 1H, H9), 6.99 (s, 1H, H7), 7.167.12 (m, 3H, 3Har), 7.11 (d, 2H, J=8.5 Hz, 2Har), 6.87 (d, 2H, J=8.5 Hz, 2Har), 4.013.97 (m, 2H, H4), 3.74 (s, 3H, OCH3), 3.653.61 (m, 2H, CH2 morph.), 3.603.57 (m, 2H, CH2 morph.), 3.002.96 (m, 2H, H6), 2.882.84 (m, 4H, CH2), 2.682.66 (m, 2H, CH2), 2.502.46 (m, 2H, CH2), 2.39 (s, 6H, CH3), 2.16 2.12 (m, 2H, H5), 1.521.48 (m, 4H, CH2). MS-ES+ (MeOH): m/z 581 (M + H+, 100%).2.3.4应用PyBOP为缩合剂合成酰胺示例二（用于合成伯酰胺） A solution of 2-(4-(2-amino-4-(2-fluoro-4-nitrophenoxy)pyridin-3-yl)phenyl)acetic acid (65 mg, 0.17 mmol) in anhydrous DMF (1.2 mL) was treated with PyBOP (125 mg, 0.24 mmol) and HOBt (32 mg, 0.24 mmol) followed by DIPEA (60 mL, 0.35 mmol) and NH4Cl (19 mg, 0.35 mmol). After stirring at room temperature for 20 min, the mixture was concentrated under vacuum and the residue partitioned between EtOAc and saturated aq. NaHCO3 solution. The EtOAc phase was washed with brine, dried (MgSO4) and concentrated in vacuo. The product was purified by flash column chromatography on SiO2 eluting with 0-8% of MeOH/CH2Cl2 to give the title compound 26 (40 mg, 62percent) as an amber colored oil. 1H NMR (DMSO-d6) d 8.23 (dd, 1H, J=10.7, 2.5 Hz), 8.05 (d, 1H, J=9.2 Hz), 7.93 (d, 1H, J=6.1 Hz), 7.42-7.32 (m, 2H), 7.33-7.25 (m, 4H), 6.92 (s, 1H), 6.25 (d, 1H, J=5.6 Hz), 5.64 (s, 2H), 3.36 (s, 2H); MS (ESI+): m/z 383.17 (M+H)+.2.4 有机磷类缩合剂多种磷酸酯和磷酰胺类缩合剂也被广泛应用于酰胺的缩合。如二苯基磷酰氯（DPP-Cl）、氰代磷酸二乙酯（DECP）、叠氮化磷酸二苯酯（DPPA、硫代二甲基磷酰基叠氮（MPTA）、 二（2-氧-3-唑烷基）磷酰氯（BOP-Cl）等。在这些磷酸酯和磷酰胺类缩合剂中，DECP常用于小量的多肽的合成， BOP-Cl特别适合与氨基酸的合成，其收率、消旋等都较好，但其缺点是，当胺的反应活性低时，常常得到酰化的唑烷。 另外，BOP-Cl 的溶解性较差，导致反应时间较长，有时会长达四五天，常用DMF做反应溶剂。2.4.1应用DPP-Cl为缩合剂合成酰胺示例 以下反应用DCC只有15%的收率, 但用DPP-Cl可以得到94%收率。2.4.2应用DPPA为缩合剂合成酰胺示例To some of this free amine 30 (0.270 g, 0.96 mmol) was added DMF (5 mL), (2-phthalimidoethoxy)acetic acid 29 (0.237 g, 0.96 mmol), DPPA (0.25 mL, 1.15 mmol) and Et3N (0.29 mL, 2.11 mmol) at 0 while stirring. The ice bath was removed after two hours and the reaction was stirred at R.T. overnight. EtOAc (70 mL) was added and the solution was extracted successively with 10% citric acid, H2O, saturated NaHCO3 solution, H2O, and saturated NaCl solution (20 mL each), dried (anhydrous MgSO4) and finnaly evaporated in vacuo. The oily residue was purified by column chromatography on silica gel, eluting with 7:1 CHCl3-MeOH to give the desired product 31 as a white solid. Yield: 81% (two steps); m.p.: 123-127 C; 1H-NMR (DMSO-d6) (ppm) = 1.10-1.25 (m, 3H, CH3), 1.65-1.95 (m, 2H, CH2-Glu-NH2), 2.23-2.40 (m, 2H, CH2-iGln), 3.44-3.60 (m, 6H, 2OCH3), 3.68 (t, J=6 Hz, CH2O), 3.80 (t, J=6 Hz, NCH2), 4.08-4.25 (m, 2H, 2CH), 4.64-4.90 (m, 1H, PNH), 7.05 (s, 1H, CONH2), 7.35 (s, 1H, CONH2), 7.40-7.60 (m, 1H, NH), 7.80-7.88 (m, 4H, phthaloyl).2.4.3应用BOP-Cl为缩合剂合成酰胺示例 (J. Med. Chem.; EN; 45; 15; 2002; 3296-3309To a solution of the acid 33 in dry CH2Cl2 (5 ml / mmol) was added diisopropyl ethylamine (DIEA, 1 equiv) under nitrogen, and the mixture was stirred for 10 min. Then, BOP-Cl (1 equiv), amine 32 (1.1 equiv) and again DIPEA (2 equiv) were added. After it was stirred overnight, most of the DCM was removed under reduced pressure and ethyl acetate (100 ml) was added. The solution was washed three times with 5% NaHCO3 solution and once consecutively with water, 2M HCl solution, water and saturated brine (50 ml each). The organic layer was dried over Na2SO4, and the solvent was evaporated to give the desired amide 34. 2.5 其它缩合剂三苯基磷-多卤代甲烷(Synth. Commun., 1990, 1105)、三苯基磷-六氯丙酮(Tetrahedron lett. 1997,6489)、三苯基磷-NBS(Tetrahedron lett. 1997,5359)等也可以用于酰胺的缩合。另外，当分子内有多个羧基存在时，有文献报道使用三（2，6-二甲氧基苯基）铋作缩合剂可选择性的将连接到伯碳原子上的羧基缩合为酰胺，而连接在仲碳和叔碳上的羧基则不反应。2.5.1应用三苯基磷-多卤代甲烷合成酰胺示例2 mmol of a carboxylic acid 37, 2 mmol of an amine 38, 2 mmol of triethylamine, and 2 mmol of carbon tetrabromide are dissolved in 5 mL of dry methylene chloride. Solid triphenyl phosphine (2 mmol, 554 mg) is then added portionwise over 5 min to the solution stirred at room temperature. After a further period of 10 min., the solvent is evaporated, and a 1:1 mixture of hexane and ethyl acetate is added. The solid triphenyl phosphine oxide is filtered off, the solvents are evaporated and the crude material can be purified by conventional methods. 2.5.2应用三苯基磷-六氯丙酮合成酰胺示例A mixture of benzoic acid (122 mg, 1mmol) and hexachloroacetone (132 mg, 0.5 mmol) in methylene chloride (2 mL) was stirred under argon and cooled down to -78. Triphenylphosphine (262 mg, 1 mmol) in methylene chloride (1 mL) was added dropwise and the mixture was stirred for 20 min. The acyl chloride solution was then treated with a solution of benzylamine (107 mg, 1 mmol) in methylene chlorid