2,2-二氟丙烷-1,3-二胺的合成研究

The Synthesis of 2,2-Difluoropropan-1,3-diamine

摘要:

常规芳香聚酰胺复合反渗透膜普遍具有易氧化的缺点，2,2-二氟丙烷-1,3-二胺(DFPDA)则是针对该问题而设计的关键功能单体。本文DFPDA是经氟化、酰胺化和还原三步反应得到。以丙二酸二乙酯为基本原料，首先经选择性氟化剂Selectfluor氟化得第一中间体2,2-二氟丙二酸二乙酯（DFDEM），所得DFDEM再经氨水酰胺化反应得到第二中间体2,2-二氟丙二酰胺(DFMA)，最后以硼烷为还原剂将中间体DFMA还原得到最终产品2,2-二氟丙烷-1,3-二胺(DFPDA)，总收率最高可达45%。研究了三步反应的工艺条件对产品收率的影响，并探讨了氟化剂的反应机理，同时采用IR、1H-NMR和GC-MS分析了每个产物的化学结构。该法原料易得，反应条件温和，操作安全，且反应收率较高。

Abstract:

The common aromatic polyamide composite reverse osmosis (RO) membrane is easy to be oxidated. 2,2-difluoro-1,3-diaminopropane (DFPDA) as a key functional monomer can be used to prepare the chlorine resistance composite reverse osmosis membrane by interfacial polymerization technology. In this study, DFPDA was synthesized through a three-step reaction including fluorination, amidation and reduction. The diethyl malonate as substrate was first reacted with the fluorination reagent of selectfluor to get the first intermediate 2,2-difluoro-diethyl-malonate(DFDEM), then the DFDEM was amidated by ammonia water to prepare the second intermediate 2,2-difluoro-malonamide(DFMA), and lastly the resulting DFMA was further reduced via boron hydride (BH3) to obtain the final product DFPDA. The reaction technologies of three steps including fluorination, amidation and reduction were investigated, and thereinto the fluorination technology was optimized through orthogonal test, at the same time the fluorination mechanism was discussed. The chemical structures of all products were identified via infrared spectra (IR), hydrogen nuclear magnetic resonance (1HNMR) and mass spectragraph (MS). This current method for preparing the DFPDA has several advantages, including the accessible substrate, mild reaction condition, safe operation and relatively high yield.