ChemicalBook CAS DataBase List 1,4-Dioxane-2,5-dione

1,4-Dioxane-2,5-dione synthesis

8synthesis methods

Product Name:1,4-Dioxane-2,5-dione
CAS Number:502-97-6
Molecular formula:C4H4O4
Molecular Weight:116.07

Weigh 50g of ethanoic acid into a 500ml double-necked flask, then add 0.05g of phenylalanine stannous catalyst (0.1wt%), pre-polymerization at atmospheric pressure, 120 ℃ under the condition of 0.5h, and then increase the temperature to 160 ℃, through the

96-35-5 Synthesis

96-35-5
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502-97-6
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$6.00/1g

Yield:502-97-6 62%

Reaction Conditions:

Stage #1:glycolic acid methyl ester with stannous octoate at 160 - 200; for 1 h;Inert atmosphere;
Stage #2: at 240; under 11.2511 Torr;Inert atmosphere;Temperature;

Steps:

1; 2
Step one, add 70g of methyl glycolate into a 250mL three-necked flask, add another 0.35g of catalyst stannous octoate, stir and heat, increase the temperature to 160°C, and pass in nitrogen, and then observe the temperature of the distillation head The boiling point of methanol should be reached, and methanol is distilled out during this process. Keep the temperature of the distillation head reaching the boiling point of methanol, and raise the temperature to 200°C after 60 minutes until the methanol is completely evaporated and a yellowish-brown solid is formed on the inner wall of the flask. Stop stirring. The product is methyl glycolate oligomer.Step 2: Put the methyl glycolate oligomer obtained in Step 1 into another three-necked flask, heat to 240°C, evacuate, and keep the vacuum in the reaction system within 1.5kPa, with light yellow crystals Distilled out. This is a crude product of glycolide.Step three, take out the crude glycolide product obtained in step two, wash it thoroughly with distilled water, and place it on a Buchner funnel for suction filtration for about 10 minutes, and then put it into a clean three-necked flask connected with a reflux condenser, and add it Good solvent (volume ratio of ethyl acetate to petroleum ether 5:1), recrystallized three times to obtain 27.97 g of glycolide. The calculated yield of glycolide is 62% (calculated as methyl glycolate).

References:

Tongji University;Zhu Zhirong;Liu Guodong CN112028868, 2020, A Location in patent:Paragraph 0037-0041; 0053-0056

79-14-1 Synthesis