Synthesis of Bis (2,2,6,6-tetramethyl-4-piperidinyl) Maleate

Fu Wang,Jiqin Zhu,Jianchi Song,Lei Wang,Shengli Zhai

doi:10.3390/60600528

Abstract

Bis (2,2,6,6-tetramethyl-4-piperidinyl) maleate is a key intermediate for the synthesis of new types of hindered amine light stabilizers (HALS), so new synthetic routes to this compound are desirable. Through an orthogonal design and follow-up single factor experiments optimal reaction conditions were determined for synthesizing bis (2,2,6,6-tetramethyl-4-piperidiny) maleate using dimethyl maleate, 2,2,6,6-tetramethyl-4-piperidinol and zeolite supported tetraisopropyl titanate as catalyst. Under the selected conditions, the reaction rate and the yield are high, the selectivity is good, the catalyst can be recycled, and there are fewer wastes. The product was characterized and quantitatively analyzed by elemental analysis, mass spectrometry, infrared spectroscopy, nuclear magnetic resonance spectroscopy and ion suppression chromatography.

Highlights

Many polymers deteriorate rapidly when they are exposed to sunlight
In the synthesis of BPM, the rate of production Y is determined by the following factors: the type of raw materials (A), the reaction temperature (B), the reaction time (C), the mixture ratio (D), the stirring rate (E), the type of catalyst (F), the level of catalyst usage (G) and the rate of distillation of the methanol produced (H)
The product was characterized by elemental analysis, mass spectrometry, infrared spectroscopy and nuclear magnetic resonance spectroscopy

Summary

Introduction

Many polymers deteriorate rapidly when they are exposed to sunlight. In order to solve this problem numerous light stabilizers have been developed. Bis (2,2,6,6-tetramethyl-4-piperidinyl) maleate (BPM) is a key intermediate for preparing new types of HALS and several synthesis methods have been reported [2~4]. A new preparation of BPM from dimethyl maleate (DMM) and 2,2,6,6-tetramethyl-4-piperidinol (TMP) in a mixture of dimethylbenzene-ethylbenzene (DE) is discussed.

Results

Conclusion