A mild high yielding synthesis of oxazole-4-carboxylate derivatives
A mild high yielding synthesis of oxazole-4-carboxylate derivatives
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DOI：
10.1016/j.tet.2010.09.014
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发表时间：
2010-11-06
期刊：
影响因子：
2.1
通讯作者：
Vilaca, Helena
中科院分区：
文献类型：
--
作者：
Ferreira, Paula M. T.;Castanheira, Elisabete M. S.;Vilaca, Helena
以N-酰基-β-卤代脱氢氨基丁酸衍生物的甲酯为原料，用2%的DBU乙腈溶液处理，高产率地合成了几种2，5-二取代恶唑-4-羧酸酯。研究了该反应的范围，发现具有β-溴脱氢氨基丁酸残基的脱氢二肽以良好的产率得到相应的恶唑。研究了所合成的恶唑类化合物在四种不同极性溶剂中的物理化学性质。所有化合物都具有较高的荧光量子产率和较好的溶剂敏感性，这使它们成为荧光探针的良好候选者。使用常规的溶液相策略将甲酯裂解成两个模型肽后，插入制备的荧光恶唑之一。在乙醇和水中研究了标记肽的物理化学性质，并与恶唑进行了比较。所得结果表明，当连接到肽链时，恶唑保持良好的荧光水平和相同的溶剂敏感性。(C)2010爱思唯尔有限公司版权所有。
Several 2,5-disubstituted oxazole-4-carboxylates were prepared in high yields from the methyl esters of N-acyl-beta-halodehydroaminobutyric acid derivatives by treatment with a 2% solution of DBU in acetonitrile. The scope of this reaction was investigated and it was found that dehydrodipeptides having a beta-bromodehydroaminobutyric acid residue gave the corresponding oxazoles in good yields. The photophysical properties of some of the oxazoles prepared were studied in four solvents of different polarity. All compounds have reasonable high fluorescence quantum yields and a moderate solvent sensitivity, which makes them good candidates to be used as fluorescent probes. One of the fluorescent oxazoles prepared was inserted after cleavage of the methyl ester into two model peptides using a conventional solution phase strategy. The photophysical properties of the labelled peptides were studied in ethanol and water and compared with those of the oxazole. The results obtained showed that the oxazole maintains a good fluorescence level and the same solvent sensitivity when linked to a peptide chain. (C) 2010 Elsevier Ltd. All rights reserved.