[EN] A PROCESS FOR SYNTHESIZING DIOL (VIII)-AN INTERMEDIATE OF MONTELUKAST SODIUM<br/>[FR] PROCEDE POUR SYNTHETISER UN DIOL (VIII), INTERMEDIAIRE DU SODIUM DE MONTELUKAST
申请人:MOREPEN LAB LTD
公开号:WO2006021974A1
公开(公告)日:2006-03-02
A process comprises preparing benzaldehyde of formula I in a conventional manner, reacting the said benzaldehyde I with Grignard reagent in water miscible etheral solvent to precipitate the alcohol of formula (II) by addition of ammonium salt and water followed by isolating the alcohol thus precipitated by any known methods and then oxidizing directly under 'Swern's conditions' to get a ketone of formula m, enolizing the said ketone in presence of a mild base such as alkali metal alkoxide and then reacting it with dialkyl carbonate under conditions effective to yield a β- ketoester of formula IV, benzylating the said β-ketoester so obtained in the preceding step to form the benzoate of formula V in presence of mild inorganic base followed by decarboxylating the said benzoate to a mixture of a ketoester of formula VI and its corresponding acid of formula VIA in the presence of acidic conditions, alkylating the acid VIA present in the mixture in the preceding step to obtain ketoester of formula VI and purifying it if so desired, asymmetrically reducing the ketoester of formula VI, to a chiral alcohol of formula VII using (-) diisopinocamphenylchloroborane (-DIPC1) in presence of less than 4 times v/w aprotic solvent and optionally in presence of Lewis base with respect to the said ketoester of formula VI, treating the said chiral alcohol VII with cerium halo salt, and alkylmagnesium halide followed by isolating the title compound using hyflow supercel and ammonium chloride to get the intermediate diol of formula VIII. Atemately, the said alcohol to Heck coupling with methyl-2-iodobenzoate in presence of Lewis base, acetonitrile, and palladium acetate to yield ketoester (VI), which is converted to diol (VIII) as described herein above.
该过程包括以传统方式制备化学式I的苯甲醛,将所述苯甲醛I与格氏试剂在水溶性醚溶剂中反应,通过加入铵盐和水使醇II沉淀,随后通过任何已知方法分离沉淀的醇,然后在“Swern条件”下直接氧化以得到化学式m的酮,使所述酮在存在弱碱(如碱金属碱)的情况下烯醇化,然后在条件下与二烷基碳酸酯反应以产生化学式IV的β-酮酯,将在前一步骤中获得的β-酮酯苄化以在温和无机碱存在下形成化学式V的苯甲酸酯,随后在酸性条件下将所述苯甲酸酯脱羧为化学式VI的酮酯和其对应酸化学式VIA的混合物,将在前一步骤中存在的酸VIA烷化以获得化学式VI的酮酯,并在必要时纯化,将化学式VI的酮酯不对称还原为手性醇化学式VII,使用(-)二异萜基氯硼烷(-DIPC1)在少于4倍体积/重量的无极性溶剂和可能在存在于所述化学式VI的酮酯相对于Lewis碱的情况下,用铈卤盐和烷基镁卤化物处理所述手性醇VII,随后使用hyflow supercel和氯化铵分离标题化合物以获得化学式VIII的中间二醇。或者,将所述醇与甲基-2-碘苯酸甲酯在Lewis碱、乙腈和乙酸钯存在下进行Heck偶联反应,得到酮酯(VI),然后将其转化为所述化学式VIII的二醇,如上所述。