申请人:Gharpure Milind Moreshwar
公开号:US20080269508A1
公开(公告)日:2008-10-30
A process for preparation of 4-hydroxy-pyran-2-one derivative of formula (I),
wherein R is,
and wherein R
1
and R
2
are methyl and R
3
is hydrogen or methyl,
comprising the steps of,
heating a compound of formula (II),
wherein R is as defined before, and R
4
is hydrogen, NH
4
+
or an alkali metal,
in a solvent mixture consisting of an aromatic hydrocarbon and a ketone in an inert atmosphere at a temperature of between 60° C. to 92° C. in the absence or presence of orthophosphoric acid or its alkali dihydrogen salts or alkali hydrogen salts of a dibasic acid, followed by optional neutralization of the reaction mixture with an organic base and obtaining compound of formula (I) in high purity and substantially free of impurities through a step of isolation and crystallization. The process leads to formation of derivatives of formula I in high purity with dimmer impurity (III) less than 0.1% and anhydro impurity (IV) below 0.15%.
一种制备式(I)的4-羟基吡喃-2-酮衍生物的过程,其中R是,R1和R2为甲基,R3为氢或甲基,包括以下步骤:在惰性气氛下,在芳香族碳氢化合物和酮的溶剂混合物中加热式(II)的化合物,其中R如上所定义,R4为氢,NH4 +或碱金属,在60℃至92℃的温度下,在正磷酸或其碱性二氢盐或二元酸的碱性氢盐的存在或缺席下,随后用有机碱中和反应混合物,并通过分离和结晶步骤获得高纯度且基本无杂质的式(I)的化合物。该过程可导致式I的衍生物高纯度,其二聚体杂质(III)小于0.1%,无水杂质(IV)低于0.15%。