Background: Agro-waste derived solvent media act as a greener process for the peptide bond formation using N^α-Fmoc-amino acid chloride and amino acid ester salt with in situ neutralization and coupling under biphasic condition. The Fmoc-amino acid chlorides are prepared by the reported procedure of freshly distilled SOCl₂ with dry CH₂Cl₂. The protocol found many added advantages such as neutralization of amino acid ester salt and not required additional base for the neutralization, and directly coupling take place with Fmoc-amino acid chloride gave final product dipeptide ester in good to excellent yields. The protocol occurs with complete stereo chemical integrity of the configuration of substrates. Here, we revisited Schotten-Baumann condition, instead of using inorganic base.

Objective: To develop green protocol for the synthesis of peptide bond using Fmoc-amino acid chloride with amino acid esters salt.

Methods: The final product isolated is analyzed in several spectroscopic and analytical techniques such as FT-IR, ¹H-, ¹³C-NMR, Mass spectrometry and RP-HPLC to check stereo integrity and purity of the product.

Conclusion: The present method developed greener using natural agro-waste (lemon fruit shell ash) derived solvent medium for the reaction and not required chemical entity.

背景：农业废弃物衍生的溶剂介质作为使用 N ^α -Fmoc-氨基酸氯化物和氨基酸酯盐在双相条件下进行原位中和和偶联形成肽键的更环保过程。Fmoc-氨基酸氯化物是通过报道的新鲜蒸馏 SOCl ₂与干燥 CH ₂ Cl _{2 的}程序制备的. 该方案发现了许多额外的优势，例如氨基酸酯盐的中和，不需要额外的碱进行中和，直接与 Fmoc-氨基酸氯化物偶联，最终产物二肽酯的产率良好至极好。该协议发生在基板配置的完整立体化学完整性中。在这里，我们重新审视了 Schotten-Baumann 条件，而不是使用无机碱。

目的：建立Fmoc-氨基酸氯化物与氨基酸酯盐合成肽键的绿色方案。

方法： 分离出的最终产物用几种光谱和分析技术（如 FT-IR、¹ H-、¹³ C-NMR、质谱和 RP-HPLC）进行分析，以检查产物的立体完整性和纯度。

结论：本方法使用天然农业废弃物（柠檬果壳灰）衍生的溶剂介质进行反应，并且不需要化学实体，从而开发出更环保的方法。