（3aR，6aS）-1,3-二苄基四氢-4H-呋喃并[3,4-d]咪唑-2，4（1H）-二酮的转化利用

在(+)-生物素的不对称全合成工艺中产生的副产物(3aR,6aS)-1,3-二苄基四氢4H-呋喃并[3,4-d]咪唑-2,4(1H)-二酮(2),经过开环酯交换、两次氧化和水解即可方便地转化得到合成(+)-生物素的关键中间体顺-1,3-二苄基-4,5-二羧基-2-咪唑烷酮,总收率74%,实现了副产物的循环利用.     

(3aR,6aS)-1,3-二苄基四氢-4H-呋喃并[3,4-d]咪唑-2,4(1H)-二酮的催化氧化工艺研究

目的研究1,3-二苄基四氢-4H-呋喃并[3,4-d]咪唑-2,4(1H)-二酮的转化利用及合成工艺。方法以1,3-二苄基四氢-4H-呋喃并[3,4-d]咪唑-2,4(1H)-二酮为原料,经醇解、TEMPO催化氧化和水解制得顺-1,3-二苄基-2-氧代咪唑-4,5-二羧酸。结果与结论目标产物结构经~1H-NMR和ESI-MS谱确证,总收率为77%(以原料计)。改进后的制备工艺具有反应条件温和、操作简便、收率高、成本低、环境友好的特点,适合于工业化生产。     

1,3-二甲基-6-[2-(对甲苯磺酰氧基)乙基氨基]尿嘧啶的合成

目的:合成盐酸尼非卡兰中间体1,3-二甲基-6-[2-(对甲苯磺酰氧基)乙基氨基]尿嘧啶.方法:以二甲基脲和氰乙酸为原料经3步反应合成目标产物.结果:以氰乙酸计,总收率44.4%.目标产物的光谱数据与文献报道一致.结论:新的合成方法所用原料价廉易得,适合生产.     

Dissociation of [3H]L-glutamate uptake from L-glutamate-induced [3H]D-aspartate release by 3-hydroxy-4,5,6,6a-tetrahydro-3aH-pyrrolo[3,4-d]isoxazole-4-carboxylic acid and 3-hydroxy-4,5,6,6a-tetrahydro-3aH-pyrrolo[3,4-d]isoxazole-6-carboxylic acid, two conformationally constrained aspartate and glutamate analogs

We characterized the interaction of two conformationally constrained aspartate and glutamate analogs, 3-hydroxy-4,5,6,6a-tetrahydro-3aH-pyrrolo[3,4-d]isoxazole-4-carboxylic acid (HIP-A) and 3-hydroxy-4,5,6,6a-tetrahydro-3aH-pyrrolo[3,4-d]isoxazole-6-carboxylic acid (HIP-B), with excitatory amino acid transporters (EAATs) in rat brain cortex synaptosomes. HIP-A and HIP-B were potent and noncompetitive inhibitors of [(3)H]L-glutamate uptake, with IC(50) values (17-18 microM) very similar to that of the potent EAAT inhibitor dl-threo-beta-benzyloxyaspartic acid (TBOA). The two compounds had little effect in inducing [(3)H]D-aspartate release from superfused synaptosomes but they potently inhibited l-glutamate-induced [(3)H]D-aspartate release, thus behaving as EAAT blockers, not substrates, in a manner similar to those of TBOA and dihydrokainate (DHK). HIP-A and HIP-B, but not TBOA and DHK, unexpectedly inhibited L-glutamate-induced [(3)H]D-aspartate release with IC(50) values (1.2-1.6 microM) 10 times lower than those required to inhibit [(3)H]L-glutamate uptake. There is therefore a concentration window (1-3 microM) in which the two compounds significantly inhibited l-glutamate-induced release with very little effect on L-glutamate uptake. This selective inhibitory effect required quite long preincubation (>5 min) of synaptosomes with the drugs. At these low concentrations, however, HIP-A and HIP-B had no effect on the EAAT-mediated [(3)H]d-aspartate release induced by altering the ion gradients, indicating that they specifically affect some L-glutamate-triggered process(es)--different from L-glutamate translocation itself--responsible for the induction of reverse transport. These data are inconsistent with the classic model of facilitated exchange-diffusion and provide the first evidence that EAAT-mediated substrate uptake and substrate-induced EAAT-mediated reverse transport are independent. Compounds such as HIP-A and HIP-B could be useful to further clarify the mechanisms underlying these operating modes of transporters.     

6,7-二氟-1-甲基-4-氧代-4H-[1,3]硫氮杂环丁烷并[3,2-α]喹啉-3-羧酸乙酯的合成工艺研究

目的：研究6，7-二氟-1-甲基-4-氧代-4H-[1，3]硫氮杂环丁烷并[3，2-α喹啉-3-羧酸乙酯的合成工艺改进方法。方法：以6，7-二氟-4-羟基-2-硫乙基-喹啉-3-羧酸乙酯为原料经乙酰化、氯代、环合步骤制备目标产物。结果：该方法工艺简单，后处理方便，且反应条件温和。结论：该合成路线易于工业化生产。     

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%。     

Synthesis and biological activity of the four stereoisomers of 6-[4-[3-[[2-hydroxy-3-[4-[2- (cyclopropylmethoxy)ethyl]phenoxy]propyl]amino]-propionamido] phenyl]-5-methyl-4,5-dihydro-3(2H)-pyridazinone, a combined vasodilator and beta-adrenoceptor antagonist

6-[4-[3-[[2-Hydroxy-3-[4-[2- (cyclopropylmethoxy)ethyl]phenoxy]propyl]amino]propionamido] phenyl]- 5-methyl-4,5-dihydro-3(2H)-pyridazinone (3) consists of a mixture of four stereoisomers, i.e., two racemates, as a consequence of the two asymmetric centers contained in the structure. An approximately equimolar mixture of these two racemates exhibits a novel combination of vasodilation and beta-adrenergic antagonist activity. This paper describes the synthesis of each of the four possible stereoisomers of 3 and provides clear evidence for the different pharmacological profile of each of the stereoisomers. The RA,SB isomer 3a has an overall profile slightly better than the complete mixture; the other three isomers all show reduced activity as vasodilators and/or beta-adrenergic antagonists.     

Metabolism of 1-, 3-, and 6-nitrobenzo[a]pyrene by intestinal microflora

The compounds 1-, 3-, and 6-nitrobenzo[a]pyrene (nitro-BaP) are environmental pollutants and have been shown to be potent bacterial mutagens. The anaerobic metabolism of these isomeric nitro-BaPs was investigated by the incubation of rat intestinal microflora with each isomer for 48 h. Aliquots were removed at several time intervals, extracted, fractionated by high-pressure liquid chromatography (HPLC), and the radioactivity determined. Metabolites were identified by comparison of their chromatographic, ultraviolet-visible absorption, and mass spectral properties with those of authentic standards. The order of the extent of nitroreduction for these isomers was 3-nitro-BaP greater than 6-nitro-BaP greater than 1-nitro-BaP. After 48 h of exposure, 84% of the added 3-nitro-BaP was present as 3-amino-BaP, 51% of the 6-nitro-BaP was metabolized to 6-amino-BaP, and 1-nitro-BaP was reduced to 1-amino-BaP (13%) and 1-nitro-BaP (4%). The order of the extent of microbial nitroreduction for these nitro-BaP isomers is different from the predictions based on electronic and steric hindrance effects. These results suggest that intestinal microflora nitroreductases exhibit a markedly high degree of substrate specificity toward nitro-BaPs that affects the extent of nitroreduction.     

PD128907中间体3-氨基-6-甲氧基-3,4-二氢-2H-苯并吡喃-4-酮盐酸盐的合成

目的：合成多巴胺D3受体选择性激动剂PD128907中间体3-氨基-6-甲氧基-3,4-二氢-2H-苯并吡喃-4-酮盐酸盐.方法：以对甲氧基苯酚为起始原料,经加成、酸解、环合、成肟、酯化和Neber重排6步反应制备了3-氨基-6-甲氧基-3,4-二氢-2H-苯并吡喃-4-酮.结果：以总收率43.4%合成了多巴胺D3受体选择性激动剂PD128907中间体,结构经核磁氢谱、质谱和红外光谱确证.结论：该法原料价廉易得,反应条件温和,收率较高.