Abstract:
A process for the purification of a compound of general formula (I), wherein R is hydrogen or C1-C6 alkyl, C2-C6 alkenyl or C2-C6 alkynyl (any of which may optionally be substituted with one or more substituents selected from halogen and OH) or COOH, COH, COOR , COR , CONR R or CONHSO2R ; R and R are each independently hydrogen or C1-C4 alkyl optionally substituted with one or more halogen atoms; R is a halogen atom or a group R ; R is hydrogen or halo; R is C1-C4 alkyl, C2-C4 alkenyl or C2-C4 alkynyl, any of which may optionally be substituted with one or more halogen atoms, or halo; or where appropriate, a salt thereof; from a mixture containing the compound of general formula (I) together with one or more isomers or di-nitrated analogues thereof; the process comprising dissolving the mixture in a suitable crystallisation solvent and recrystallising the product from the resulting crystallisation solution; characterised in that the crystallisation solution contains not more than 25 % loading of the compound of general formula (I) wherein loading is defined as: weight of pure compound of formula (I) x 100/weight of pure compound of formula (I) + weight of solvent, and in that the temperature to which the solution is cooled for crystallisation is not greater than about 30 DEG C.
Abstract translation:用于纯化通式(I)的化合物的方法,其中R 1是氢或C 1 -C 6烷基,C 2 -C 6烯基或C 2 -C 6炔基(其任何一个可以任选地被一个或多个取代基取代 选自卤素和OH)或COOH,COH,COOR 4,COR 6,CONR 4 R 5或CONHSO 2 R 4; R 4和R 5各自独立地为氢或任选被一个或多个卤素原子取代的C 1 -C 4烷基; R 6是卤素原子或基团R 4; R 2是氢或卤素; R 3是C 1 -C 4烷基,C 2 -C 4烯基或C 2 -C 4炔基,其中任何一个可以任选地被一个或多个卤素原子或卤素取代; 或其合适的盐; 由含有通式(I)的化合物的混合物与一种或多种异构体或其二硝化类似物一起混合; 所述方法包括将所述混合物溶解在合适的结晶溶剂中并从所得结晶溶液中重结晶产物; 其特征在于结晶溶液含有不超过25%的通式(I)化合物的负载量,其中负载量定义为:式(I)的纯化合物的重量×100 /式(I)的纯化合物的重量+ 溶剂的重量,并且溶液冷却至结晶的温度不大于约30℃。
Abstract:
A process for the preparation of halonitroalkanes, e.g. bromonitromethane, is disclosed in which a nitroalkane is reacted with an alkali metal base or an alkaline earth metal base, and the resulting nitroalkane salt is halogenated to form the halonitroalkane in a reaction mixture. The process is improved by acidifying the reaction mixture, preferably to pH = 0-4, and thereafter recovering the halonitroalkane by azeotropic distillation of the reaction mixture. The acidification step increases the amount of halonitroalkane recovered, as compared to prior art processes in which the reaction mixture is distilled without prior acidification.
Abstract:
Production of chlorine-substituted olefine compounds of formula (I), wherein: R1 represents a C-organic rest; R2 represents -CN, -CO-R3, -CO-S-R3, -CO-O-R3, -CO-N(R?4, R5); R3¿ represents a C-organic rest; R4, R5 represent H, C-organic rest. The process is bared on the reaction of oxiranes of formula (II) in the presence of a carboxylic acid amide (IIIa) or a lactam (IIIb) in the liquid phase with a chlorinating agent of formula (IV). Process products of formula (I) are important intermediate products for the production of dyes, pharmaceuticals and plant-protecting agents.