Studies On Synthesis Of 3,9-Bis {2-[3-(3-Tert-Butyl-4-Hydroxy-5-Methylphenyl) Propionyloxy]-1, 1-Dimethyl}-2,4,8,10-Tetraoxaspiro [5,5] Undecane As A Novel Antioxidant

3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-l ,1 -dimethyl}-2,4,8,10-tetraoxaspiro[5,5]undecane(AO-80) was a new kind of antioxidant used in plastic which has been neither commercially produced nor studied in laboratory. In this paper, synthesis of AO-80 was studied through aldol condensation and transesterification using formaldehyde, iso-butyraldehyde, pentaerythritol and 3-(3-tert-butyl-4-hydroxy- 5-methylphenyl)propionate(KY-250) as raw materials.Preparation of hydroxypivalaldehyde through aldol condensation using formaldehyde(37%~40%) and iso-butyraldehyde as starting materials and triethylamine as catalyst was studied. The influences of adding method of reactants, ratios of reactants, amount of catalyst, reaction temperature and reaction time on reaction results were examined. The obtained optimum reaction conditions were: n(formaldehyde) : n(isobutyraldehyde) n(triethylamine) = 1.1 : 1 : 0.06, reaction temperature 70℃ and reaction time 6 hours. Moreover, it was indicated that hydroxylpivalaldehyde could not be dried by heating at high temperature for its sublimation property, so only be dried under room temperature. Under above optimum reaction and drying conditions, the yield of hydroxylpivalaldehyde was 94.9%. The structure of the product was characterized by IR and MS. The detailed studies on synthesis, purification and identification of hydroxypivalaldehyde in this paper has not been reported in literature.The preparation of 3,9-bis(1-1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro [5,5]undecane(spiroglycol) was studied using hydroxylpivalaldehyde and pentaerythritol as starting materials, hydrochloric acid as catalyst and water as solvent. Compared with organic solvent used in literature, it was easier for spiroglycol product to be separated from the reaction mixture after reaction when using water as solvent. The obtained optimum reaction conditions were: n(hydroxypivalaldehyde) : n(pentaerythritol) : n(hydrochloric acid) = 2.3 : 1 : 0.06, reaction temperature 60℃ and reaction time 10 hours. Under above optimum reaction conditions, the yield of spiroglycol was 94.2%, which was much higher than those reported in literatures.A novel method, so called one-step method, for preparation of spiroglycol was...