Lilial CAS 80-54-6

Method 1: Add 2-methyl-3-(p-tert-butyl)phenylacrolein, solvent, and catalyst together into a high-pressure reactor, and carry out selective hydrogenation reaction to synthesize lyral under hydrogen gas of 0.01-0.1MPa . Include the following steps in order:

1) Add 2-methyl-3-(p-tert-butyl)phenylacrolein, solvent, and catalyst into the autoclave, replace with nitrogen, and then pass in hydrogen. The reaction temperature is 20-200°C, and the reaction time is 2 -10 hours to produce lyral.

2) Transfer the synthetic reaction solution to a vacuum distillation vessel, distill off the solvent under normal pressure, and distill off lyral under reduced pressure. The catalyst remains in the distillation pot and is recycled for reuse. The distilled solvent is recycled to the hydrogenation reaction process for use. The catalyst is a complex formed by nickel chloride, nickel acetate and organic macromolecular ligands, which is used after reduction, and its concentration range is 1.0-10%.

3) The proportioning (weight) range of raw materials used in the synthesis method of lyral aldehyde by highly selective hydrogenation of p-tert-butyl-alpha-methylphenylacrolein is: raw material 40-60%; solvent 30-60%; nickel complex compound 1-10%; hydrogen 0.5-1% (link hydrogen); the sum of each component is 100%.

Method two: add 32.4kg p-tert-butylbenzaldehyde, 60kg methyl alcohol and the aqueous solution (concentration 15%) that contains 3.5kg sodium hydroxide in reactor, mix and stir, drop n-propanal 12kg in the time of 25 ℃, carry out For the condensation reaction, after the addition of n-propionaldehyde is completed, the temperature is raised, for example, at 45-55° C. for 1.5-2 hours. Acetic acid is added to adjust the pH to 4.5-6.5. After the condensation reaction is completed, methanol is recovered by distillation, and the methanol recycling sleeve is used in the above condensation reaction. A thin-film evaporator is used for continuous distillation at 45Pa, and the residence time of the material in the evaporator is 14-18s to obtain a light yellow solid with a melting point of 69°C, a gas chromatography analysis purity of 95%, and a yield of 90%. GS-MS analysis molecular weight is 202, which was confirmed as p-tert-butyl-α-methylphenylacrylaldehyde by 1H-NMR detection. Drop into p-tert-butyl-α-methylphenylacrolein, solvent methanol and Pd/C catalyst in the hydrogenation kettle, the feed ratio (weight)=1:1 of methyl alcohol and tert-butyl-α-methylphenylacrylaldehyde The feed ratio (weight) of catalyst and tert-butyl-α-methylphenylacrolein=2: 1000, then the air in the still is pumped out by the vacuum pump connected on the hydrogenation kettle, and after 3 times of replacement with nitrogen, the purity With more than 99.99% hydrogen, the temperature is raised to 60-65 ° C, and the reaction is carried out at 0.5 MPa under the condition of stirring. Carry out pressure filtration after hydrogenation finishes, and remove solvent methyl alcohol, obtain lyral crude product, this crude product is carried out rectifying, obtain final product lyral, be colorless transparent liquid, refractive index (nd20) is 1.505, specific gravity ( 25°C, mg/mL) is 0.945; acid value (mgKOH/g) is 1.5, GC content (area normalization method): m‑LLY is 1.2%, p‑LLY is 97.5%; moisture is 0.20%.