Hydroxycarboxamide, an Important Intermediate for Chemical Synthesis

The resulting a-hydroxycarboxamides have been interestingly employed as intermediate for the synthesis of more complex scaffolds, hi fact, as in Ugi reaction (Chapter 7), the combination of these MCRs with a further transformation has gained much attention in the last years for the preparation of structurally diverse complex molecules. Many 

Since oxazolines are privileged structures in medicinal chemistry, the authors explored the stability of final oxazolines 62 and it was found that they were completely stable at pH 7.4, decomposition (10%) was observed under prolonged (24 h) exposure to pH 5 solutions, and complete hydrolysis was observed at pH 3. This is interesting since these molecules could exhibit biological applications. 

COsH CbzHN COsH BocHN CO2H BocHN CO2H 

SCHEME 8.23 Passerini-Zhu/Staudinger-aza-Wittig protocol (a) IBX, THF, MW (150W), 100°C (b) polymer supported triphenylphos- 

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