4-氨基-8-去氮杂四氢叶酸二乙酯的新合成方法

针对4-氨基-8-去氮杂四氢叶酸二乙酯现有合成方法中化合物极性大、溶解度差、收率低的缺点,采用在2,4位氨基引入保护基的方法进行改进。以6-乙酰氧基-2,4-二氯吡啶并[3,2-d]嘧啶为原料,在2,4-位引入苄基后与对氨基苯甲酰谷氨酸二乙酯连接,经硼氢化钠和氯化镍还原后再脱保护,生成叶酸类抑制剂关键中间体4-氨基-8-去氮杂四氢叶酸二乙酯。此方法所需时间短,收率较高,操作及后处理方便。并对6-乙酰氧基-2,4-二氯吡啶并[3,2-d]嘧啶苄基化的选择性、硼氢化钠和氯化镍还原方法进行了讨论。此方法对于四氢叶酸类化合物的合成有重要参考意义。     

5-[4-羟(氨)基苄基]-2-硫代-2,4-咪唑啉二酮磺酸酯(酰胺)的合成及其生物活性

以5-(4-羟基/氨基苄基)-2-硫代-2,4-咪唑啉二酮为原料,在三乙胺作傅酸剂的条件下与取代磺酰氯反应,得到28个新的5-(4-羟基/氨基苄基)-2-硫代-2,4-咪唑啉二酮苯磺酸酯/酰胺类化合物,它们的化学结构经1H NMR,MS和元素分析确证.初步生测结果表明:在100μg/mL浓度下,部分目标化合物均对供试植物病原菌和油菜显现出一定的抑制活性,如5-(4-氨基苄基)-2-硫代-2,4-咪唑啉二酮对碘苯磺酰胺(4d)对黄瓜灰霉病菌抑制率为80.7%,5-(4-羟基苄基)-2-硫代-2,4-咪唑啉二酮邻甲基苯磺酸酯(3n)和5-(4-氨基苄基)-2-硫代-2,4-咪唑啉二酮-2,4-二氯苯磺酰胺(4m)对油菜的生长抑制率分别为87.4%和81.5%.     

N~8-去氮-N~5-取代四氢叶酸类似物的设计合成及生物活性研究

以2,4-二氨基-6-羟甲基吡啶并[3,2-d]嘧啶为原料,在4-位氨基转换为羟基后与对氨基苯甲酰谷氨酸二乙酯连接生成叶酸类似物分子骨架,采用Adams催化方法还原吡啶环,在N5-位连接不同类型的取代基得到3个新的N8-去氮四氢叶酸类似物.经1H NMR,MS对化合物的结构进行了表征.初步生物活性结果表明,此类化合物对人重组二氢叶酸还原酶的抑制活性与N5-位的取代基有关联.     

新型酰基硫脲及酰基脲的合成及其杀虫活性

以5-(4-氨基苄基)-2-硫代-2,4-咪唑啉二酮、5-(4-氨基苄基)-2,4-咪唑啉二酮和5-(4-氨基苯基)-2,4-咪唑啉二酮为原料,分别与取代苯/吡啶甲酰基异氰酸/异硫氰酸酯反应合成了15个新型含2,4-咪唑啉二酮杂环的酰基硫脲及酰基脲类化合物.它们的结构经IR,1H NMR和HR-ESI-MS的确证.以粘虫(Mythimna separata)、棉铃虫(Helicoverpa armigera),玉米螟(Ostrinia nubilalis)、小菜蛾(Plutella xylostella)、蚜虫(Aphis laburni)和蚊幼虫(Culex pipiens pallens)为试虫测试了它们的生物活性,结果表明部分化合物特别是5-(4-氨基苯基)-2,4-咪唑啉二酮-2,4,6-三氯苯甲酰基硫脲(4)在600 mg/L测试浓度下对棉铃虫、玉米螟、小菜蛾的死亡率分别为85%,90%和100%,在10和5 mg/L测试浓度下对蚊幼虫的死亡率均为100%,表现出良好的杀虫活性.     

新型嘧啶单环类非经典叶酸拮抗剂的合成及抗肿瘤活性研究

以课题组前期设计合成的非经典叶酸拮抗剂6-(4'-甲基苯乙基)-N5-氯乙酰基-2,4-二氨基哌啶并[3,2-d]嘧啶(wm-8.2)为先导化合物,将wm-8.2中的哌啶并嘧啶双环结构简化为嘧啶单环结构,以提高分子柔韧性并简化分子结构,根据6-位空间占位设计6-H和6-甲基两个系列,考察了不同桥链长度和不同芳香杂环侧链对抗肿瘤活性的影响.同时对具有叶酸抑制剂分子结构特征的关键中间体进行活性对比测定,研究了N(5)位氯乙酰基对活性的影响.两个系列目标化合物和关键中间体共36个化合物的结构均经1H NMR,13C NMR和MS确证.生物活性测定表明,6位为甲基的化合物中,具有三碳桥链及对甲基苯环侧链的6-甲基-2,4-二氨基-5-(N-(4-甲基苯基)丙基-N-(2-氯乙酰基))氨基嘧啶(6b-3)具有最好的HL-60、A549和HCT116细胞增殖抑制活性,IC50分别为0.25,0.83和0.63μmol?L^-1.化合物6b-3在N(5)位氯乙酰基取代之前的关键中间体6-甲基-2,4-二氨基-5-(N-(4-甲基苯基)丙基)氨基嘧啶(5b-3)具有最优的二氢叶酸还原酶抑制活性.总结了化合物的构效关系,并用计算机模拟进行了阐释.     

4-氨基-N8,N10-二碳杂-N5-取代四氢叶酸类似物的合成及生物活性研究

以2,4-二氨基-6-羟甲基吡啶并[3,2-d]嘧啶为原料,与对甲酰基苯甲酰谷氨酸二乙酯发生Wittig反应构建叶酸类似物的骨架结构,还原吡啶环得到4-氨基-8,10-二碳杂四氢叶酸类似物,在N5位取代不同基团得到四个新的4-氨基-N8,N10-二碳杂四氢叶酸类化合物,经1H NMR,13C NMR和MS对化合物的结构进行了表征.初步生物活性结果表明,此类化合物对人重组胸苷酸合成酶的抑制作用与N5位取代基有关,2个化合物在0.1 μmol·L-1的浓度下对HL-60白血病细胞的抑制率达到60％以上.     

嘧啶（硫）醚类化合物的合成及除草活性

以2,4-二氯嘧啶为起始物设计并合成了一系列4-芳(硫)氧基-2-氯嘧啶和4-芳氧基-2-二甲氨基嘧啶化合物。利用2,4-二氯嘧啶2个氯原子的活性差异,酚取代嘧啶环上4位氯原子,然后二甲氨基取代2位的氯原子。所合成的化合物均经过了1H NMR和元素分析确证。为了确证酚首先在嘧啶环的4位发生亲核取代反应,用X衍射法测定了化合物3d的单晶结构。初步生物活性测定结果表明,大部分化合物都表现出一定的除草活性,其中化合物7c、7j、7k和7m在1.0×10-4g/mL质量浓度下对油菜的抑制率达到了80%以上。     

2-位或4-位取代吡啶并嘧啶类非经典叶酸拮抗剂的合成及抗肿瘤活性

以非经典叶酸拮抗剂2,4-二氨基-6-(4-甲基苯基)乙基吡啶并[3,2-d]嘧啶(wm-5b)及其侧链简化产物2,4-二氨基吡啶并[3,2-d]嘧啶为先导化合物, 选取具有抗肿瘤活性的基团, 通过微波法高效合成了2-位或4-位取代吡啶并嘧啶类非经典叶酸拮抗剂, 研究了2-位及4-位取代基对抗肿瘤活性的影响, 为非经典叶酸拮抗剂的设计合成提供了更多的理论依据. 目标化合物的结构均经核磁共振波谱(NMR)和质谱(MS)确证. 生物活性测定结果表明, 所有目标化合物均具有抗肿瘤活性, 其中, 6-(4-甲基苯基)乙基-4-氨基-2-(3-氯-4-氟苯基)氨基吡啶并[3,2-d]嘧啶(6b)对HL-60细胞的IC₅₀=(4.09±0.48) μmol/L, 对A549细胞的IC₅₀=(17.99±7.20) μmol/L, 而对HCT116细胞的IC₅₀=(14.52±4.74) μmol/L; 部分目标化合物具有二氢叶酸还原酶抑制活性. 此外, 对部分目标化合物和先导物进行了二氢叶酸还原酶晶体结构的分子对接, 对活性结果和构效关系从分子水平上进行解释.     

N-酰基-N-间氟苄基-6-氨基香豆素的合成及除草活性

以N-间氟苄基-6-氨基香豆素为先导,利用活性亚结构拼接原理,设计、合成了一系列N-酰基-N-间氟苄基-6-氨基香豆素衍生物,其结构用1H NMR、ESI-MS和元素分析表征,N-三氟乙酰基取代的化合物d5结构经X-ray单晶衍射进一步确证.采用琼脂小杯法和盆栽法对合成化合物的除草活性进行了初步研究.结果表明,100 mg/L分别为N-氯乙酰基、N-溴乙酰基、N-三氟乙酰基、N-(2,4-二氯苯氧乙酰基)取代的化合物d2,d3,d5和d17对反枝苋根、茎的抑制率大于75%,优于乙草胺EC;1500 g/ha分别为N-溴乙酰基、N-(2,4-二氯苯氧乙酰基)取代的化合物d3和d17对反枝苋等双子叶杂草茎叶处理的抑制率达76%以上;同剂量化合物d17对单子叶作物小麦、玉米和水稻安全.     

3-取代苄基-6-三氟甲基嘧啶-2,4(1H,3H)-二酮衍生物的合成及其除草活性的研究

为了进一步研究3-取代苄基-6-三氟甲基嘧啶-2,4(1H,3H)-二酮衍生物的除草活性, 以期发现更高活性化合物, 合成了16个未见文献报道的3-取代苄基-6-三氟甲基嘧啶-2,4(1H,3H)-二酮衍生物, 其结构均经过¹H NMR, IR和元素分析确证. 生测结果表明, 嘧啶环1-位取代基的变化, 不仅影响化合物的抑制活性与选择性, 可能还改变了化合物的作用方式. 定量的结构与活性关系研究表明, 当作用对象为油菜时, 化合物的活性可能主要与取代基R的摩尔分子折射常数有关; 当作用对象为稗草时, 化合物的活性可能主要与取代基R的电性参数有关. 1-位为氢时, 有利于对油菜生长的抑制; 1-位为甲基时, 有利于对稗草生长的抑制.     

Sequence Analysis of Polypeptide by Mass Spectrometry

The method described in this work provides a sensitive and fast technique for investigating the primary structure of peptides with molecular weight up to 3340 amu. Usually, the metastable ion kinetic energy spectra (MIKES) and collisional activated decomposition (CAD) spectra provide complementary information for the FAB mass spectra, the MIKES and CAD spectra generally contain high-mass sequence ions.     

Synthesis and structural study of novel 5-aryl substituted 2-amino-4,7-dioxopyrido[2,3-d]pyrimidines

The tide compounds 4a-c have been prepared in a one-step procedure from 2,4-diamino-6-hydroxy-pyrimidine (1) and the corresponding arylidene substituted Meldrum's acids 2a-e in very good yields. Semiempirical theoretical calculations (AMI) reveal two favoured conformations ( A and B ) for compounds 4a-e. The ¹H-nmr determinations, by using Karplus and Altona equations, clearly indicate that conformation A, with the aryl group on C5 in a pseudoaxial position, is that predominant in solution. The calculated charge density values for the olefinic carbons are in agreement with the experimental push-pull effect observed in the ¹³C-nmr spectra.     

3-(D-葡萄糖-1-基)-6-芳基-7H-1，2，4-三唑并[3，4-b][1，3，4]噻二嗪类化合物的合成及波谱研究

ω-溴代芳香基乙酮与3-(D-葡萄糖-1-基)-4-氨基-5-巯基-1，2，4-三唑反应 合成了一系列新颖的3-(D-葡萄糖-1-基)-6-芳基-7H-1，2，4三唑并[3，4-b[1，3 ，4]噻二嗪．用元素分析，IR，NMR，MS对其结构进行了表征，研究了其NMR波谱特 征，并以^1H-^1H COSY，^13C-^1H COSY，COLOC二维NMR技术对其^1H NMR，^13C NMR的谱峰进行了全归属     

Folate antagonists. 16. Antimalarial and antibacterial effects of 2,4-diamino-6-[(heterocyclic)thio,sulfinyl, and sulfonyl]quinazolines

The reaction of 5-chloro-2-nitrobenzonitrile with a variety of mercaptoheterocycles provided the corresponding 2-nitro-5-[(heterocyclic)thio]benzonitriles. Reduction to the amine followed by cyclization with chloroformamidine hydrochloride afforded a series of 2,4-diamino-6-[(hetero-cyclic)thio]quinazolines. Bromination, oxidation, and amidine formation were accomplished with 2,4-diamino-6-[(4-phenyl-2-thiazolyl)thio]quinazoline (23) to provide additional analogs. Several of these compounds exhibited suppressive antimalarial activity against drug-sensitive lines of Plasmodium berghei in mice.     

Isomer differentiation and structural characterization of penem β-lactam antibiotics by mass-analyzed ion kinetic energy spectrometry

A number of clinically significant penem β-lactams, both free acids and sodium salts, were investigated by mass-analyzed ion kinetic energy spectrometry (MIKES) following fast atom bombardment (FAB) ionization. The collisionally activated dissociation (CAD) products of [M + H] ⁺ and [M + Na]⁺ ions are described. Carbon dioxide loss was observed for some of the free acids, whereas a daughter ion generated by β-lactam ring cleavage was characteristic of the sodiated species. Other fragments included successive cleavages and rearrangements of the substituent side-chain, permitting complete characterization of these chains. The fragmentation pattern for both protonated and sodiated species were more clearly established by CAD MIKES than by normal FAB mass spectral analyses. A notable feature of this technique was its ability to differentiate between pairs of regioisomeric penems on the basis of their fragmentation patterns. These compounds could not be differentiated in the usual mass spectra.     

Synthesis of 3,5-disubstituted 1,3,4-oxadiazole-2-thiones as potential fungicidal agents

Sixteen new 3-arylaminomethyl-5-(2,4-dichlorophenyl)-1,3,4-oxadiazole-2-thione and six 3-alkyl aryl alkyl-5-(2,4-dichlorophenyl)-1,3,4-oxadiazole-2-thiones were synthesised and characterised by their sharp melting points, elemental analysis, ir, ¹H nmr and mass spectra. These substituted oxadiazolethiones were screened for their fungitoxic properties. Most of the compounds showed toxicity against two test organisms, Curvularia verruciformis and Alternaria tenuis. The degree of inhibition ranged from 38--100% for a few compounds.     

Synthesis of amino-5-arylsulfonylpyrimidines

Several new 4-amino-5-arylsulfonylpyrimidines were prepared via the reaction of various α-(ethoxymethylene)arylsulfonylacetonitriles with guanidine or variously substituted amidines (Table II). 2,4-Diamino-5-(p-chlorophenylsulfonyl)pyrimidine (IIIg), a typical example, was prepared from the reaction of 2-(p-chlorophenylsulfonyl)-3-ethoxyacrylonitrile (IId) with guanidine in refluxing ethanol containing sodium ethoxide. With proper substitution of the ethoxymethylene intermediate, the method was found suitable for the preparation of other compounds having either a hydroxy or methyl group at the 4-position of the 5-arylsulfonylpyrimidine. The fluoro group in 2,4-diamino-5-(p-fluorophenylsulfonyl)pyrimidine (IIIx) was successfully replaced by nucleophilic reagents such as sodium ethoxide, N-methylpiperazine and N,N-diethylethylene-diamine. Attempts at direct displacement of fluorine by ammonia at 190° were unsuccessful.     

Studies on biologically active heterocycles. Part I. Synthesis and antifungal activity of some new aroyl hydrazones and 2,5-disubstituted-1,3,4-oxadiazoles

A series of new 1-(2,4-dichlorobenzoyl) hydrazones and 2-aryl/aralkyl-5-(2,4-dichlorophenyl)-1,3,4-oxadiazoles have been synthesized from 2,4-dichlorobenzoylhydrazine and different aldehydes. Subsequent ring closure of the substituted aroyl hydrazones yielded the 1,3,4-oxadiazoles. All the compounds were characterized by their sharp melting point, microanalysis, ir, ¹H nmr and mass spectra and screened for their fungitoxic properties against Alternaria tenuis and Curvularia verruciformis. A few of the compounds showed good activity.     

Synthesis, antiinflammatory and antimicrobial activities of some 2,4-dichloro-5-fluorophenyl substituted arylidenetriazolothiazolidinones

A series of 2,4-dichloro-5-fluorophenyl substituted arylidenetriazolothiazolidinones were obtained by one-pot reaction of 3-(2,4-dichloro-5-fluorophenyl)-4H-1,2,4-triazole-5-thiol with substituted benzaldehydes and monochloroacetic acid in the presence of acetic anhydride, acetic acid, and sodium acetate. The structures of the newly synthesized compounds were characterized and confirmed by IR, ¹H NMR, mass spectra, and elemental analysis. Compounds bearing the 4-methylthiophenyl, 3,4-methylenedioxyphenyl, and 2,3,5-trichlorophenyl moiety showed excellent antiinflammatory activity. The antimicrobial screening studies revealed that compounds with 4-anisyl, 4-methylthiophenyl, 3,4-methylenedioxyphenyl, and 2,3,5-trichlorophenyl at position 5 of the arylidenetriazolothiazolidinone moiety showed excellent activity against all tested strains at 6.25 μg cm⁻³ concentrations.     

Infrared and Raman spectra of 3,5-diamino-6-(o-C6H4X)-1,2,4-triazines [X = F,Cl, Br,CH3

Raman and infrared spectra of four substituted 3,5-diamino-6-(ortho-substituted phenyl)-1,2,4-triazines, having ortho-fluoro, -chloro, -bromo and -methyl groups on the phenyl ring, are reported and discussed. Bands due to substituent sensitive phenyl vibrations are observed in both the Raman and infrared spectra. The Raman spectra of all four compounds have strong bands near 770 and 1330 cm(-1) which are assigned to the ring breathing vibration of the 1,2,4-triazine ring and an asymmetric triazine C-NH2 stretching vibration, respectively. A medium/strong band near 800 cm(-1) in the infrared spectra is attributed to an out-of-plane bending vibration of the substituted 1,2,4-triazine ring.