Procedure for the preparation of racemic derivatives of 1,5-diaryl-3-trifluoromethyl-delta2-pyrazolines
申请人:Alcon-Marrugat Monserrat
公开号:US20050096474A1
公开(公告)日:2005-05-05
Procedure for preparation of compounds with the general formula 1, which include the racemic mixtures (±)-1, and the enantiomerically pure compounds (−)-1 and (+)-1, wherein R
1
and R
3
, like or different, represent an atom of hydrogen, chlorine, fluorine, a methyl, trifluoromethyl or methoxy group; R
2
represents an atom of hydrogen, chlorine, fluorine, a methyl, trifluoromethyl, methoxy, trifluoromethoxy, methylsulphonyl or aminosulphonyl group; R
4
represents an atom of hydrogen, chlorine, fluorine, a methyl, trifluoromethyl, methoxy, trifluoromethoxy, methylsulphonyl or aminosulphonyl group, with the condition that one of the substituents R
2
or R
4
is a methylsulphonyl or aminosulphonyl group; which involves obtaining the racemic mixture with the general formula (±)-1 by reacting an (E)-1,1,1-trifluoro-4-aryl-3-buten-2-one with a phenylhydrazine, followed by a treatment with chlorosulphonic acid, or by reacting with chlorosulphonic acid followed by a reaction with sodium hydroxide and, finally, with thionyl chloride. The product obtained by either of these methods is made to react with ammonium carbonate or ammonia, or with sodium sulphite and methyl iodide or methyl sulphate. In addition, to obtain the enantiomerically pure compounds with the general formula 1 by resolving the racemic mixture with the general formula (±)-1, a reaction is effected with optically active ephedrine, followed by formation of the sodium salt of each enantiomer, reaction with thionyl chloride and ammonium carbonate or ammonia, or instead with thionyl chloride followed by sodium sulphite and methyl iodide or methyl sulphate to thereby obtain separately the enantiomerically pure compounds with the general formulae (−)-1 and (+)-1.
通式 1 化合物的制备步骤,包括外消旋混合物 (±)-1 和对映体纯化合物 (-)-1 和 (+)-1,其中 R
1
和 R
3
代表氢原子、
氯原子、
氟原子、甲基、三
氟甲基或甲氧基;R
2
代表氢、
氯、
氟、甲基、三
氟甲基、甲氧基、三
氟甲氧基、甲基磺酰基或
氨基磺酰基的原子; R 4
4
代表氢原子、
氯原子、
氟原子、甲基、三
氟甲基、甲氧基、三
氟甲氧基、 甲基磺酰基或
氨基磺酰基,条件是其中一个取代基 R
2
或 R
4
是甲磺酰基或
氨磺酰基;其方法是将(E)-1,1,1-三
氟-4-芳基-3-
丁烯-2-酮与苯
肼反应,然后用
氯磺酸处理,或与
氯磺酸反应,然后与
氢氧化钠反应,最后与亚
硫酰氯反应,得到通式为(±)-1的外消旋混合物。通过上述任一方法得到的产品都会与
碳酸铵或
氨反应,或与
亚硫酸钠和
碘甲烷或
硫酸甲酯反应。此外,为了通过解析通式(±)-1 的外消旋混合物来获得通式 1 的对映体纯化合物,需要与具有光学活性的
麻黄碱进行反应,然后生成每种对映体的钠盐、与亚
硫酰氯和
碳酸铵或
氨反应,或先与亚
硫酰氯反应,再与
亚硫酸钠和
碘甲烷或
硫酸甲酯反应,从而分别获得通式为 (-)-1 和 (+)-1 的对映体纯化合物。