2-（5-氨基-1，2，4-噻二唑-3-基）-2-（Z）-甲氧亚氨基乙酸S-苯并噻唑硫酯的合成

2-(5-氨基-1,2,4-噻二唑-3-基)-2-(Z)-甲氧亚氨基乙酰胺与2-巯基苯并噻唑为原料,哌啶为溶剂,在三乙胺催化下反应制得头孢菌素中间体2-(5-氨基-1,2,4-噻二唑-3-基)-2-(Z)-甲氧亚氨基乙酸S-苯并噻唑硫酯,收率约76%。     

(Z)-2-(5-氨基-1,2,4-噻二唑-3-基)-2-甲氧亚氨基乙酸的合成

目的 合成头孢唑兰中间体(Z)-2-(5-氨基-1,2,4-噻二唑-3-基)-2-甲氧亚氨基乙酸。方法 以氰乙酰胺为起始原料,依次经甲氧亚氨化、加成、酯化、与硫氰化钾反应、构型转换和水解共6步反应制得目标化合物。结果和结论 目标化合物的结构经¹H-NMR和MS谱确证。该工艺路线原料易得,操作简便,总收率为29.8%,具有一定的工业化价值。     

(6R,7R)-7-[2-呋喃基(甲氧亚氨基)乙酰氨基]-3-羟甲基-8-氧代-5-硫杂-1-氮杂二环[420]辛-2-烯-2-甲酸的合成研究

目的　制备(6R,7R) - 7-[2 -呋喃基(甲氧亚氨基)乙酰氨基] - 3-羟甲基- 8-氧代- 5 -硫杂- 1-氮杂二环[4 2 0]辛- 2 -烯- 2 -甲酸。方法　通过7-氨基头孢烷酸的水解,生成去乙酰基7-氨基头孢烷酸,再与2 - (2 -呋喃基)- 2 -甲氧亚胺基乙酸氯反应进行7位氨基的酰化制备上述医药中间体。结果及结论　适宜的反应条件为:7-氨基头孢烷酸在- 2 5℃水解,与2 - (2 -呋喃基) - 2 -甲氧亚胺基乙酰氯在- 10℃反应,二者的摩尔比为1 0∶1. 15,收率可达80 %。     

2-[(吡啶-4-基)甲基氨基]-N-[4-(三氟甲基)苯基]苯甲酰胺的合成工艺研究

目的合成2-[(吡啶-4-基)甲基氨基]-N-[4-(三氟甲基)苯基]苯甲酰胺(Ⅰ)。方法以邻硝基苯甲酸为起始原料,经氯代、氨解、水合肼还原、缩合、硼氢化钠还原共5步反应合成得到目标化合物Ⅰ。结果与结论经5步反应合成了目标化合物Ⅰ,其结构经核磁共振氢谱、质谱确证。改进后的合成工艺反应条件温和,操作简便,收率可达54.5%。     

2,4-二甲基-5-甲酰基-1H-吡咯-3-甲酸的合成

乙酰乙酸叔丁酯经系列反应得到的氨基酮与乙酰乙酸乙酯经Knorr反应得2，4-二甲基-3-乙氧羰基-1H-吡咯-5-羧酸叔丁酯，再经甲酰化、水解得抗肿瘤药舒尼替尼的重要中间体2，4-二甲基-5-甲酰基-1H-吡咯-3-甲酸，总收率约为44％。     

Alpelisib的合成工艺改进

文章对小分子抗肿瘤药物alpelisib(BYL719,1)的合成方法进行了改进。以2,4-二溴吡啶为原料,依次经亲核取代、硅醚化保护和脱保护、甲磺酰化及取代等5步反应引入三氟甲基得到关键中间体4-溴-2-(1,1,1-三氟-2-甲基丙烷-2-基)-吡啶(8)。中间体8与[2-[(叔丁氧羰基)氨基]-4-甲基噻唑-5-基]硼酸在钯催化下,经Suzuki偶联反应得[4-甲基-5-[2-(1,1,1-三氟-2-甲基丙烷-2-基)吡啶-4-基]噻唑-2-基]氨基甲酸叔丁酯,再进行脱Boc保护及缩合等反应得到目标化合物1,总收率约15.9%。     

盐酸头孢唑兰的合成

目的 研究抗生素盐酸头孢唑兰的合成方法.方法 以7-氨基头孢烷酸(7-ACA)为原料,在三乙胺催化下与(Z)-2-(5-氨基-1,2,4-噻二唑-3-基)-2-甲氧亚氨基硫代乙酸(S-2-苯并噻唑)酯缩合得7β-[(Z)-2-(5-氨基-1,2,4-噻二唑-3-基)-2-甲氧哑氨基乙酰氨基]头孢烷酸,再经六甲基二硅胺烷硅烷化保护,与咪唑并[1,2-b]哒嗪在三甲基碘硅烷(TMSI)催化下进行3-位取代反应,然后经甲醇脱保护,阴离子交换树脂除碘离子,最后与盐酸成盐得盐酸头孢唑兰.结果 目标化合物总收率为15%,结构经MS,IR和1H-NMR确证.结论 用本法合成盐酸头孢唑兰,原料易得,操作简便,易于工业化生产.     

3-(氨基烷氧基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物的设计、合成与乙酰胆碱酯酶抑制活性

目的初步探讨在7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物母核C-3位苯环侧链中引入二乙胺基团的3-(氨基烷氧基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物的合成及其乙酰胆碱酯酶抑制活性。方法以取代的苯甲醛和乙酰甘氨酸为初始原料,经Erlenmeyer-Plchl反应、缩合反应、水解反应、缩合反应,生成6-芳甲基-3-硫代-1,2,4-三嗪-5(2H)-酮类化合物,再与取代的α-氯代苯乙酮反应,得到6-芳甲基-3-(羟基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物;以芳基乙烯为原料,经温和的氧化反应、缩合反应得到3,4-二氢-6-芳基-3-硫代-1,2,4-三嗪-5(2H)-酮类化合物,再与取代的α-氯代苯乙酮在乙酸中反应得到6-芳基-3-(羟基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物。两条合成路线得到的3-(羟基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物进一步经Williamson反应制备得到10个3-(烷氧基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物。所有目标化合物结构均经质谱、红外光谱和核磁共振氢谱确证。采用Ellman法对目标化合物进行体外乙酰胆碱酯酶抑制活性筛选。结果根据前期已筛选化合物的活性数据和总结出的初步构效关系,设计并合成了10个C-3位苯环侧链中含有二乙胺基团的3-(氨基烷氧基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物。体外乙酰胆碱酯酶抑制活性筛选表明,所有目标化合物均具有乙酰胆碱酯酶抑制活性,其中7个化合物在10μmol.L-1浓度水平抑制活性超过了50%。结论根据体外重组人源AChE(rhAChE)抑制活性的测试结果,发现C-3位苯环侧链中含有二乙胺基团的7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物均具有较好的rh-AChE抑制活性。在这一位置的侧链中引入二乙胺基团,可以增强化合物对rhAChE的抑制活性。     

头孢克肟的合成

7-氨基-3-乙烯基头孢烷酸和[(2-氨基-噻唑-4-基)-(苯并噻唑-2-基-硫基羰基)亚甲基氨基氧基]乙酸叔丁酯经酰胺化、水解等反应合成头孢克肟,总收率35.8%.     

水合肼还原制备3-氨基-2-[(2''-氰基联苯-4-基)甲基]氨基-苯甲酸乙酯的工艺研究

目的研究3-氨基-2-[(2’-氰基联苯-4-基)甲基]氨基-苯甲酸乙酯的最优合成工艺。方法以2-[(2’-氰基联苯-4-基)-甲基]氨基-3-硝基苯甲酸乙酯为原料,水合肼为还原剂,Pb/C为催化剂,还原制得。结果原料与还原剂的最佳物质的量比为1.92:1,催化剂Pd/C为1.2g,反应温度为75℃,反应时间2h的最优条件下,收率为92.0%。结论本合成工艺稳定,条件温和,产率高,适合3-氨基-2-[(2’-氰基联苯-4-基)甲基]氨基-苯甲酸乙酯的工业化生产。     

Studies on anti-MRSA parenteral cephalosporins. I. Synthesis and antibacterial activity of 7beta-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2(Z)- hydroxyiminoacetamido]-3-(substituted imidaz

In order to improve the antibacterial activity of cefozopran (CZOP) against methicillin-resistant Staphylococcus aureus (MRSA), we initiated chemical modification to introduce a 2-(5-amino-1,2,4-thiadiazol-3-yl)-2(Z)-hydroxyimino acetyl group at the C-7 position and a 3- or 6-substituted imidazo[1,2-b]pyridazinium or 5-substituted imidazo[1,2-a]pyridinium group at the C-3' position. Although this approach successfully enhanced the anti-MRSA activity of CZOP two to eight times, a slight decrease in the activity against Gram-negative bacteria including Pseudomonas aeruginosa was involved. Among the novel derivatives, 3-(6-aminoimidazo[1,2-b]pyridazinium-1-yl)methyl-7beta-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2(Z)hydroxyiminoacetamido]-3-cephem-4-carboxylate (44a) showed an excellent balance of activity against MRSA and Gram-negative bacteria.     

Synthesis of 2-(3-Substituted-1,2,4-oxadiazol-5-yl)-8-methyl-8-azabicyclo[3.2.1]octanes and 2α-(3-Substituted-1,2,4-oxadiazol-5-yl)-8-methyl-8-azabicyclo[3.2.1]oct-2-enes as Potential Muscarinic Agonists

Radioligand binding affinities of seven muscarinic receptor ligands which possess an oxadiazole ring side chain have been determined in rat heart, rat brain, and m₁- or m₃-transfected CHO cell membrane preparations to determine the selectivity for subtypes of muscarinic receptor. The ratios of binding constants in brain membranes were measured as an indicator of potential agonist activity against [³H]QNB and [³H]Oxo-M. These muscarinic ligands did not discriminate the subtypes of muscarinic receptors. Six muscarinic ligands which have a 3-amino- or 3-methyl-1,2,4-oxadiazol-5-yl groups attached to the 8-methyl-8-azabicyclo[3.2.1]oct-2-ene or 8-methyl-8-azabicyclo[3.2.1]octane head group show binding constants between 2.04 x 10^–6 and 1.79 x 10^–5 M in rat heart, rat brain, and m₁- or m₃-transfected CHO cell membrane preparations. 1-Methyl-2-[3-amino-1,2,4-oxadiazol-5-yl]piperidine shows low binding constants of approximately 10^–4 M in rat heart and rat brain. (1R,5S)-2-[3-Amino-1,2,4-oxadiazol-5-yl]-8-methyl-8-azabicyclo-[3.2.1]oct-2-ene [(1R,5S)-17] was the most active compound.     

Studies on condensed-heterocyclic azolium cephalosporins. IV. Synthesis and antibacterial activity of 7 beta-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2(Z)- alkoxyiminoacetamido]-3-(condensed-heterocyclic azolium)methyl cephalosporins including SCE-2787.

The synthesis and in vitro antibacterial activity of 7 beta-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2(Z)-alkoxyiminoacetami do] cephalosporins bearing various condensed-heterocyclic azolium groups at the 3 position in the cephalosporin nucleus are described. The thiadiazolyl cephalosporins showed good antibacterial activity against both Gram-positive and Gram-negative bacteria and the MICs of the thiadiazolyl cephalosporins against Pseudomonas aeruginosa was more potent than that of the corresponding 7 beta-[2-(2-aminothiazol-4-yl)-2(Z)-alkoxyiminoacetamido]-3- (condensed-heterocyclic azolium)methyl cephalosporins. Also, the thiadiazolyl cephalosporins bearing (imidazo[1,2-b]-pyridazinium-1-yl)methyl groups at the 3 position showed antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). Among the cephalosporins tested, 7 beta-[2-(5- amino-1,2,4-thiadiazol-3-yl)-2(Z)-methoxyiminoacetamido]-3-(imidaz o[1,2- b]pyridazinium-1-yl)methyl-3- cephem-4-carboxylate (4, SCE-2787) which exhibited the most potent antibacterial activity and the broadest antibacterial spectrum was selected as a parenteral cephalosporin candidate for further biological evaluation.     

Synthesis and antiviral properties of (E)-5-(2-bromovinyl)-2'-deoxycytidine-related compounds

Treatment of 3',5'-di-O-acetyl-(E)-5-(2-bromovinyl)-2'-deoxyuridine (2) with p-chlorophenyl phosphorodichloridate and 1,2,4-triazole gave 1-(3,5-di-O-acetyl-2-deoxy-beta-D-erythro-pentofuranosyl)-(E)-5-(2-br o movinyl)- 4-(1,2,4-triazol-1-yl)pyrimidin-2(1H)-one (3). Reaction of 3 with ammonia gave (E)-5-(2-bromovinyl)-2'-deoxycytidine (1), the overall yield from 2 being 60%. A similar 4-(1,2,4-triazol-1-yl) derivative (4) was obtained from 3',5'-di-O-acetyl-thymidine by the use of phosphoryl chloride as the condensing agent. Treatment of thymidine with trimethylsilyl chloride and then with phosphoryl chloride and 1,2,4-triazole gave upon workup 1-(2-deoxy-beta-D-erythro-pentofuranosyl)-5-methyl-4(1,2,4-triazol -1-yl) pyrimidin-2(1H)-one (5). (E)-5-(2-Bromovinyl)-2'-deoxyuridine (BVDU) when similarly treated gave the corresponding (E)-5-(2-bromovinyl) compound 7. A minor product formed in both cases was a 4-(1,2,4-triazol-1-yl) derivative in which the nucleoside 5'-hydroxyl group had been replaced by chlorine (6 and 8). Whereas compounds 4-6 and 8 did not exhibit a selective antiviral effect, compounds 1-3 and 7 proved almost as active as the reference compound BVDU. In particular, compound 7, the 4-triazolyl derivative of BVDU, would seem worth pursuing for its potential as an inhibitor of herpes simplex virus type 1 and varicella-zoster virus.     

Synthesis and structure-activity relationships of 5-amino-6-fluoro-1-[(1R,2S)-2-fluorocyclopropan-1-yl]-8-methylquinolonecarboxylic acid antibacterials having fluorinated 7-[(3R)-3-(1-aminocyclopropan-1-yl)pyrrolidin-1-yl] substituents

A series of novel 5-amino-6-fluoro-1-[(1R,2S)-2-fluorocyclopropan-1-yl]-8-methylquinolones bearing fluorinated (3R)-3-(1-aminocyclopropan-1-yl)pyrrolidin-1-yl substituents at the C-7 position (2-4) was synthesized to obtain potent drugs for infections caused by Gram-positive pathogens, which include resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA), penicillin-resistant Streptococcus pneumoniae (PRSP), and vancomycin-resistant enterococci (VRE). These fluorinated compounds 2-4 exhibited potent antibacterial activity comparable with that of a compound bearing a non-fluorinated (3R)-3-(1-aminocyclopropan-1-yl)pyrrolidine moiety at the C-7 position (1) and had at least 4 times more potent activity against representative Gram-positive bacteria than ciprofloxacin (CPFX), gatifloxacin (GFLX), or moxifloxacin (MFLX). Among them, the 7-[(3S,4R)-4-(1-aminocyclopropan-1-yl)-3-fluoropyrrolidin-1-yl] derivative 3 (=DQ-113), which showed favorable profiles in preliminary toxicological and nonclinical pharmcokinetic studies, exhibited potent antibacterial activity against clinically isolated resistant Gram-positive pathogens.     

Quinoxaline derivatives. Part II: Synthesis and antimicrobial testing of 1,2,4-triazolo[4,3-a]quinoxalines, 1,2,4-triazino[4,3-a]quinoxalines and 2-pyrazolylquinoxalines

Three main classes of quinoxaline derivatives have been synthesized. The first class comprises the synthesis of three novel series of 1,2,4-triazolo[4,3-a]quinoxalines; namely 1-substituted-1,2,4-triazolo[4,3-a]quinoxalines 3a-f, 1-substituted aminomethyl-1,2,4-triazolo[4,3-a]quinoxalines 14a-d and 1-cyano or ethoxycarbonylmethyl-1,2,4-triazolo[4,3-a]quinoxalines 6, 12. The second class involves the synthesis of 2-substituted-1 H-1,2,4-triazino[4,3-a]quinoxalines 4a-d. The third class deals with the synthesis of a variety of 2-pyrazolylquinoxalines, namely 2-(5-amino-3-arylpyrazol-1-yl)-3-phenylquinoxalines 5a-d, 2-[5-hydroxy-3-phenyl-4-(4-substituted sulfamoylphenyl)azopyrazol-1-yl]-3-phenylquinoxalines 15a, b, and 2-(5-hydroxy-4-nitroso-3-phenylpyrazol-1-yl)-3-phenylquinoxalin e (16). The prepared compounds were tested in vitro for their antimicrobial activity. Compounds 13 and 14b exhibited promising antifungal activity against C. albicans (MIC 25, 50 mu/ml respectively). Compound 13 was as active as the antibiotic nystatin.     

Synthesis and biological evaluation of 9-[5'-(2-oxo-1,3,2-oxazaphosphorinan-2-yl)-beta-D-arabinosyl]ade nine and 9-[5'-(2-oxo-1,3,2-dioxaphosphorinan-2-yl)-beta-D-arabinosyl]ade nine: potential neutral precursors of 9-[beta-D-arabinofuranosyl]adenine 5'-monophosphate

9-[5'-(2-Oxo-1,3,2-oxazaphosphorinan-2-yl)-beta-D-arabinosyl]adeni ne (1c) and 9-[5'-(2-oxo-1,3,2-dioxaphosphorinan-2-yl)-beta-D-arabinosyl]adeni ne (1d) were synthesized by reaction of 9-[beta-D-arabinofuranosyl]adenine with phosphoryl chloride with 1-amino-3-propanol and 1,3-propanediol, respectively. 1c consisted of a mixture of diastereomers, while 1d was enantiomerically homogeneous. The structures of these compounds were established by spectral (1H NMR, MS, UV) and elemental analyses. Both 1c and 1d were resistant to degradation by 5'-nucleotidase, alkaline phosphatase, venom phosphodiesterase, crude snake venom, adenosine deaminase, and adenylate deaminase. Neither compound was significantly biotransformed by mouse hepatic microsomal preparations in the presence of an NADPH-generating system. Compound 1c was marginally effective at prolonging the life span of mice bearing P-388 leukemia; compound 1d, however, was inactive.     

Studies on anti-MRSA parenteral cephalosporins. III. Synthesis and antibacterial activity of 7beta-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2(Z)-alkoxyiminoacetamido-3

In the course of our exploration for a novel cephalosporin derivative having excellent antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), we modified the C-3 linked spacers of cephem derivatives bearing a 1-methylimidazo[1,2-b]pyridazinium-6-yl group at the C-3' position and 2-(5-amino-1,2,4-thiadiazol-3-yl)-2(Z)-cyclopentyloxy-iminoacetyl group at the C-7 position. The optimal spacers were the (E)-2-vinyl and (E)-2-thiovinyl groups seen in 19a and 29aa, respectively. Their anti-MRSA activity was 16 to 32 times as potent as that of cefozopran (CZOP). Focusing on the (E)-2-vinyl and (E)-2-thiovinyl spacers, we further modified the alkoxyimino groups in the C-7 acyl moiety and the 1-alkylimidazo[1,2-b]pyridazinium moieties at the C-3' position and investigated the structure-activity relationships (SAR) of the derivatives. Consequently, we selected 7beta-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2(Z)-fluoromethoxyiminoacetamido]-3-[(E)-2-(1-methylimidazo[1,2-b]pyridazinium-6-yl)thiovinyl]-3-cephem-4-carboxylate (29ca) as a new anti-MRSA parenteral cephalosporin candidate for further biological evaluation. The selected 29ca showed anti-MRSA activity comparable to that of vancomycin (VCM) both in vitro and in vivo, high affinity (IC50)=2.7 microg/ml) for penicillin binding protein 2' (PBP2') of MRSA and potent activity against Gram-negative bacteria as well.