申请人:Zelinsky Institute of Organic Chemistry
公开号:US06008407A1
公开(公告)日:1999-12-28
The present invention provides a method of preparing ortho-difluorobenzene derivatives, which comprises (a) providing a mixture of cyclohexenes by reacting chlorotrifluoroethylene (CTFE) and 1.3-diene in a flow reactor and distilling the resultant, and (b) dehydrohalogenating the mixture of cyclohexenes with a phase transition catalyst in :he presence of alkali metal hydroxide at temperature range of 40 to 150.degree. C. without using any organic solvent. The distillate having low boiling point, which is obtained during distillation of the resultant, is recycled into the flow reactor. The present invention also provides a method of preparing 2-chloro-4,5-difluorobenzoic acid, which comprises (a) providing a mixture of 4-chloro-1-methyl-4,5,5-trifluorocyclohexene and 5-chloro-1-methyl-4,4,5-trifluorocyclohexene by reacting chlorotrifluoroethylene (CTFE) and isoprene and distilling the resultant. (b) dehydrohalogenating said mixture in the presence of alkali metal hydroxide and a phase transition catalyst to form 3,4-difluorotoluene, to reacting said 3,4-difluorotoluene with chlorine gas without using any organic solvent to form 2-chloro-4,5-difluorotoluene, (d) photo-reacting said 2-chloro-4,5-difluorotoluene with chlorine gas under a lighting mercury lamp without using any organic solvent to form 2-chloro-4,5-difluorobenzotrichloride, and (e) reacting said 2-chloro-4,5-difluorobenzotrichloride with aqueous acid solution without using any organic solvent. The present invention also provides a method of preparing 2-chloro-4,5-difluorobenzoyl chloride by reacting the 2-chloro-4,5-difluorobenzotrichloride of step (e) above with zinc oxide.
本发明提供了一种制备邻二氟苯衍生物的方法,包括(a)通过在流动反应器中将氯三氟乙烯(CTFE)和1,3-二烯反应并提供环己烯混合物,然后蒸馏所得产物,以及(b)在无有机溶剂的情况下,使用相变催化剂在碱金属氢氧化物的存在下,将环己烯混合物在40至150摄氏度的温度范围内脱氢卤化。在蒸馏所得产物时,获得的低沸点馏分被回收至流动反应器中。本发明还提供了一种制备2-氯-4,5-二氟苯甲酸的方法,包括(a)通过将氯三氟乙烯(CTFE)和异戊二烯反应并提供4-氯-1-甲基-4,5,5-三氟环己烯和5-氯-1-甲基-4,4,5-三氟环己烯的混合物,然后蒸馏所得产物,(b)在碱金属氢氧化物和相变催化剂的存在下,将所述混合物脱氢卤化以形成3,4-二氟甲苯,(c)在无有机溶剂的情况下,将所述3,4-二氟甲苯与氯气反应以形成2-氯-4,5-二氟甲苯,(d)在无有机溶剂的情况下,在光照汞灯下将所述2-氯-4,5-二氟甲苯与氯气光反应以形成2-氯-4,5-二氟苯三氯甲烷,以及(e)在无有机溶剂的情况下,将所述2-氯-4,5-二氟苯三氯甲烷与水酸溶液反应。本发明还提供了一种通过将上述步骤(e)中的2-氯-4,5-二氟苯三氯甲烷与氧化锌反应来制备2-氯-4,5-二氟苯甲酰氯的方法。