Synthesis of bis (2,2,6,6-tetramethyl-4-piperidinyl) maleate

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.