Diphenyl (2,3-dihydro-2-thioxo-3-benzoxazolyl)phosphonate (1) prepared from 2-benzoxazolethiol and diphenyl phosphorochloridate was proved to be a very useful condensing agent. A variety of amides, esters, and dipeptides were obtained in excellent yields. Furthermore, this reagent was successfully applied to the synthesis of β-lactams from β-amino acids.

中文翻译：

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二苯基（2,3-二氢-2-硫代-3-苯并恶唑基）膦酸酯：一种用于通过缩合合成酰胺、酯、肽和 β-内酰胺的新型反应性缩合剂

由 2-苯并恶唑硫醇和磷酸二苯酯制备的二苯基 (2,3-二氢-2-硫代-3-苯并恶唑基) 膦酸酯 (1) 被证明是一种非常有用的缩合剂。以极好的收率获得了多种酰胺、酯和二肽。此外，该试剂成功地应用于由β-氨基酸合成β-内酰胺。