Process for the preparation of 2-nitro-5-phenoxy-N-alkylsulfonyl benzamides by nitration
申请人:IMPERIAL CHEMICAL INDUSTRIES PLC
公开号:EP0274194A1
公开(公告)日:1988-07-13
A process for preparing a compound of formula (II):
or a tautomer or salt thereof in substantially pure form wherein R¹ is C1-6 alkyl optionally substituted by one or more halogen atoms; R³ is hydrogen, fluorine, chlorine, bromine or iodine, C1-6 alkyl, trifluoromethyl or a cyano group; R⁴ is hydrogen, fluorine, chlorine, bromine, iodine or trifluoromethyl; R⁵ is fluorine, chlorine, bromine, iodine or trifluoromethyl; and R⁶ is hydrogen or C1-4 alkyl;
which process comprises nitrating a compound of formula (III):
or a salt thereof wherein R¹, R³, R⁴, R⁵ and R⁶ are as defined above, in a solvent which is resistant to nitration under the desired reaction conditions and suitable for purification of the product of formula (II), heating the resultant solution to a temperature sufficient to at least partially dissolve the desired product and impurities and cooling the solution to precipitate the compound of formula (II) in substantially pure form.
一种制备式(II)化合物的工艺:
或其基本纯的同分异构体或盐 其中 R¹ 是任选被一个或多个卤原子取代的 C1-6 烷基;R³ 是氢、氟、氯、溴或碘、C1-6 烷基、三氟甲基或氰基;R⁴ 是氢、氟、氯、溴、碘或三氟甲基; R⁵ 是氟、氯、溴、碘或三氟甲基;以及 R⁶ 是氢或 C1-4 烷基;
该工艺包括硝化式 (III) 的化合物:
或其盐,其中 R¹、R³、R⁴、R⁵ 和 R⁶ 如上文所定义,在所需反应条件下可抗硝化且适合于提纯式 (II) 产物的溶剂中,将所得溶液加热至足以至少部分溶解所需产物和杂质的温度,然后冷却溶液以析出基本纯的式 (II) 化合物。