With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.185815-59-2,4-Isobutyldihydro-2H-pyran-2,6(3H)-dione,as a common compound, the synthetic route is as follows.
Cool the dark brown oil (D number) obtained in the previous step to room temperature.Dilute with 147 g of methyl tert-butyl ether;Add 114g concentrated ammonia water and 215ml water to the 1000ml reaction bottle to cool down;The above mixed droplets are added to the ammonia water under stirring at 25 C or lower.After the dropwise addition is completed, the reaction is continued for 35 minutes at 25 C or lower;After the reaction is completed, the layers are separated, and the organic layer is extracted under reduced pressure. The aqueous layer is slowly adjusted to pH = 1.5 with concentrated hydrochloric acid (about 119 g) under stirring, and a large amount of solid is precipitated. After the completion of the dropwise addition, the temperature is lowered to 0 to 10 C, filtered, and filtered. The cake was washed with 115 ml, and the crude product was dried under reduced pressure. The dried crude product was dissolved in ethyl acetate 615 ml at 70 C, then filtered, cooled and crystallized, cooled to 0 to 5 C, filtered, and the filter cake was washed with 115 ml of iced ethyl acetate, and then dried under reduced pressure.110.9 g of amide (trait: white solid, melting point 106-108 C),The yield was 59.3% (based on ethyl cyanoacetate).
The synthetic route of 185815-59-2 has been constantly updated, and we look forward to future research findings.
Reference£º
Patent; Langfang Zekang Pharmaceutical Technology Co., Ltd.; Sun Yuqin; Yang Weimin; (5 pag.)CN109320430; (2019); A;,
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