Method 1: Add 2-methyl-3-(p-tert-butyl) phenyl acrolein, solvent and catalyst to the autoclave, and carry out selective hydrogenation reaction under hydrogen 0.01-0.1MPa to synthesize lilylaldehyde . The following steps are included in sequence:
1) 2-methyl-3-(p-tert-butyl) phenyl acrolein, solvent and catalyzer are added in autoclave, replace with nitrogen, then feed hydrogen, reaction temperature 20-200 ℃, reaction time 2 -10 hours, spawns Lily Aldehyde.
2) Transfer the synthetic reaction solution to a vacuum distillation vessel, distill out the solvent under normal pressure, and steam out Lily Aldehyde under reduced pressure. The catalyst remains in the distillation still and is recycled for reuse. The distilled solvent is recycled for use in the hydrogenation reaction process. The catalyst is nickel chloride, a complex formed by nickel acetate and organic macromolecular ligands, which is used after reduction, and its concentration is in the range of 1.0-10%.
3) The proportioning (weight) scope of the raw materials used in the Lily Aldehyde synthesis method by high-selectivity hydrogenation of p-tert-butyl-α-methylphenyl acrolein is: raw material 40-60%; solvent 30-60%; nickel complexation Compound 1-10%; hydrogen 0.5-1% (connected to hydrogen); the sum of each component is 100%.
Method 2: add 32.4kg p-tert-butylbenzaldehyde, 60kg methyl alcohol and the aqueous solution (concentration 15%) containing 3.5kg sodium hydroxide in the reactor, mix and stir, drip n-propionaldehyde 12kg at 25 ° C, carry out In the condensation reaction, after the dropwise addition of n-propionaldehyde, the temperature is raised, for example, the temperature is kept at 45-55° C. for 1.5-2 hours. Acetic acid is added to adjust the pH to 4.5-6.5, the condensation reaction is completed, methanol is recovered by distillation, and the methanol is recycled and used in the above condensation reaction. A thin-film evaporator was used for continuous distillation at 45Pa, and the residence time of the material in the evaporator was 14-18s to obtain a light yellow solid with a melting point of 69°C. The gas chromatography analysis purity was 95%, the yield was 90%, and the GS-MS analysis molecular weight was 202, confirmed to be p-tert-butyl-α-methylphenylacrolein through 1H-NMR detection. Drop into p-tert-butyl-α-methylphenyl acrolein, solvent methanol and Pd/C catalyst in the hydrogenation kettle, the charging ratio (weight) of methanol and tert-butyl-α-methylphenyl acrolein=1:1 The feed ratio (weight)=2: 1000 of catalyzer and tert-butyl-α-methyl phenyl acrolein, then pump out the air in the kettle by the vacuum pump connected on the hydrogenation kettle, after replacing 3 times with nitrogen, fill with purity With more than 99.99% hydrogen, the temperature is raised to 60-65°C, and the reaction is carried out at 0.5MPa under stirring. After the hydrogenation, pressure filtration was performed, and the solvent methanol was removed to obtain a Lily Aldehyde crude product, which was subjected to rectification to obtain the final product Lily Aldehyde, which was a colorless and transparent liquid with a refractive index (nd20) of 1.505 and a specific gravity (25° C. , mg/mL) was 0.945; acid value (mgKOH/g) was 1.5, GC content (area normalization method): m-LLY was 1.2%, p-LLY was 97.5%; moisture was 0.20%.
