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ChemicalBook CAS DataBase List 1,4-Dioxaspiro[4.5]decan-8-one
4746-97-8

1,4-Dioxaspiro[4.5]decan-8-one synthesis

11synthesis methods
-

Yield:4746-97-8 97.8%

Reaction Conditions:

with 1-butyl-3-methylimidazolium hydrogen sulfate;water;1-ethylimidazolium tetrafluoroborate at 110 - 132; for 5.5 h;Temperature;Reagent/catalyst;

Steps:

1

Add to a 500mL three-necked bottle0.4molDimethyl 1,4-cyclohexanedione-2,5-dicarboxylate,0.44mol of ethylene glycol,0.8mol of water,0.8mol of 1-butyl-3-methylimidazolium hydrogensulfateAnd 0.2mol of 1-ethylimidazole tetrafluoroborate,Stir and heat up,Gradually low boiling substances are produced,And steam out the low-boiling substances,After heating to 110,Incubate the reaction for 1.5h.Then continue to heat up the system,Accompanied by the steaming of low-boiling substances,After the temperature rose to 132°C,Incubate the reaction for 4h.Cool down to 55,Add 200mL toluene,Stir for 40min,Cool down to 25,Let stand to dispense,To obtain a toluene layer and an ionic liquid layer,The ionic liquid layer was repeatedly extracted with 100 mL of toluene once,Combine the separated toluene layers,The separated toluene layer solution was concentrated by rotary distillation to obtain 62.8g of light yellow1,4-Cyclohexanedione monoethylene glycol ketal crude product,The gas chromatographic purity is 99.28%,The mass yield was 99.92%.Then use 180mL heptane to heat and dissolve the obtained1,4-Cyclohexanedione monoethylene glycol ketal crude product,Pass a preheated chromatography column containing 30g silica gel (80-120 mesh) under normal pressure,The preheating temperature is 50,Wash the column with 60mL hot heptane after each pass,Rinse twice,Combine the column liquid,After cooling,Freeze crystallization, filtration,61.2g of 1,4-cyclohexanedione monoethylene glycol ketal white crystals were obtained,The gas chromatography purity is 99.72%,The mass yield is 97.80%.The separated ionic liquid layer is directly applied to the next batch of reactions.

References:

CN111763193,2020,A Location in patent:Paragraph 0007; 0026; 0027; 0028; 0029; 0030

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