2-Acetylbutyrolactone synthesis
- Product Name:2-Acetylbutyrolactone
- CAS Number:517-23-7
- Molecular formula:C6H8O3
- Molecular Weight:128.13
Yield:517-23-7 96%
Reaction Conditions:
Stage #1: 4-butanolide;acetic acid methyl esterwith sodium methylate in methanol at 45 - 90; under 750.075 Torr; for 10 h;Inert atmosphere;Large scale;
Stage #2: with carbon dioxide in methanol;water at 0 - 35; under 6000.6 Torr; for 0.5 h;Large scale;Temperature;Pressure;Reagent/catalyst;
Steps:
1-15; 1-3 (1) Acylation reaction:
the reaction is carried out in a dry 50L stainless steel reaction tank equipped with stirring, reflux and distillation equipment. Turn on the stirring, replace the reaction tank with nitrogen, add 10.3 kg of methyl acetate, raise the temperature in the reaction tank to 45°C, add 4 kg of γ-butyrolactone and 3.76 kg of sodium methoxide in batches, and keep the system temperature at 45°C. The reaction system is gradually heated to 55°C, the valve of the distillation device is slowly opened, the reflux ratio is controlled to be 3:1, and the mixture of methanol and methyl acetate generated by the reaction is collected about 8kg for rectification, separation and recovery. At the same time, slowly add 7kg of methyl acetate, slowly increase the temperature, the pressure in the tank is 0.1MPa, and the reaction is maintained at 90°C for 10h. The reaction system was monitored by gas chromatography that about 1% of γ-butyrolactone remained.(2) Neutralization reaction: Cool the reaction system in step (1) to 0°C to 5°C, start to replace the gas in the tank with carbon dioxide twice, control the temperature of the system to 35°C, pass carbon dioxide gas into the tank and keep the tank The internal carbon dioxide pressure is 0.8MPa. Start slowly adding 0.7 kg of water dropwise, after the dropwise addition is complete, stir for 30 minutes.(3) Separation: The reaction system in step (2) is filtered by pressure, the solid is washed with methyl acetate and dried to obtain sodium bicarbonate, which is collected as a by-product; the filtrate is first subjected to atmospheric distillation to distill the mixture of methyl acetate and methanol 9.5kg is combined with the distilled product in step (1) to rectify and separate; the remaining liquid in the tank is transferred to a 10L bottle to continue high-vacuum and reduced-pressure distillation under a pressure of less than 1000Pa to obtain 5.73kg of α-acetyl- γ-butyrolactone, its purity and yield are shown in Table 1.
References:
CN111620844,2020,A Location in patent:Paragraph 0053-0123
