The present invention relates to a process for obtaining amidated fatty acids or derivatives thereof good in color even after longer storage with low concentrations of undesired by-products. The present invention also relates to use of amidated fatty acids or derivatives thereof obtained by the process in the cosmetic applications. Further, the present invention also relates to use of amidated fatty acids or derivatives thereof obtained by the process in the industrial applications.

The present invention relates to a process for obtaining amidated fatty acids or derivatives thereof good in color even after longer storage with low concentrations of undesired by-products. The present invention also relates to use of amidated fatty acids or derivatives thereof obtained by the process in the cosmetic applications. Further, the present invention also relates to use of amidated fatty acids or derivatives thereof obtained by the process in the industrial applications.

The present invention relates to a brivaracetam intermediate, a preparation method therefor, and a preparation method for brivaracetam. The steps of the method for preparing brivaracetam described in the present invention are short and the raw materials are cheap, moreover, the method is simple and highly effective without requiring isomer separation by means of column chromatography or asymmetric synthesis, being suitable for industrial large-scale production. In addition, disclosed by the present invention is a compound as shown in formula (II), which may be used for the synthesis of brivaracetam. ##STR00001##

The present invention relates to a brivaracetam intermediate, a preparation method therefor, and a preparation method for brivaracetam. The steps of the method for preparing brivaracetam described in the present invention are short and the raw materials are cheap, moreover, the method is simple and highly effective without requiring isomer separation by means of column chromatography or asymmetric synthesis, being suitable for industrial large-scale production. In addition, disclosed by the present invention is a compound as shown in formula (II), which may be used for the synthesis of brivaracetam. ##STR00001##

The invention provides a method of purifying 5-acetamido-N,N′-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophathalamide, comprising adding a portion of acid to a stream comprising crude 5-acetamido-N,N′-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophathalamide in a solvent and continuously crystallising the 5-acetamido-N,N′-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophathalamide from the crude 5-acetamido-N,N′-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophathalamide, with removal of at least a fraction of the solvent, wherein the crystallisation is carried out in a continuous reactor, wherein the continuous reactor is a plug flow reactor. At least three further portions of acid are added to the continuous reactor during the crystallisation.

The invention provides a method of purifying 5-acetamido-N,N′-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophathalamide, comprising adding a portion of acid to a stream comprising crude 5-acetamido-N,N′-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophathalamide in a solvent and continuously crystallising the 5-acetamido-N,N′-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophathalamide from the crude 5-acetamido-N,N′-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophathalamide, with removal of at least a fraction of the solvent, wherein the crystallisation is carried out in a continuous reactor, wherein the continuous reactor is a plug flow reactor. At least three further portions of acid are added to the continuous reactor during the crystallisation.

The invention provides a method of purifying 5-acetamido-N,N′-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophathalamide, comprising adding a portion of acid to a stream comprising crude 5-acetamido-N,N′-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophathalamide in a solvent and continuously crystallising the 5-acetamido-N,N′-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophathalamide from the crude 5-acetamido-N,N′-bis(2,3-dihydroxypropyl)-2,4,6-triiodoisophathalamide, with removal of at least a fraction of the solvent, wherein the crystallisation is carried out in a continuous reactor, wherein the continuous reactor is a plug flow reactor. At least three further portions of acid are added to the continuous reactor during the crystallisation.

The present invention provides a method for preparing a pregabalin intermediate 3-carbamoymethyl-5-methylhexanoic acid without solvent. The method comprises the following steps: a) cooling an ammonia water system to a certain temperature; b) adding 3-isobutylglutaric anhydride dropwise to the system, then keeping temperature, and reacting; c) after completing the reaction, adding an acid to the system to adjust pH; d) after adjusting pH, cooling, then keeping temperature, crystallizing, then suction filtering and drying; and e) adding a solvent to the dried substance, slurrying, and suction filtering and drying to obtain the final product. The method provided in the present invention for preparing 3-carbamoymethyl-5-methylhexanoic acid is high-yield, green, environmentally-friendly, simple and convenient, and of less pollution.

The present invention provides a method for preparing a pregabalin intermediate 3-carbamoymethyl-5-methylhexanoic acid without solvent. The method comprises the following steps: a) cooling an ammonia water system to a certain temperature; b) adding 3-isobutylglutaric anhydride dropwise to the system, then keeping temperature, and reacting; c) after completing the reaction, adding an acid to the system to adjust pH; d) after adjusting pH, cooling, then keeping temperature, crystallizing, then suction filtering and drying; and e) adding a solvent to the dried substance, slurrying, and suction filtering and drying to obtain the final product. The method provided in the present invention for preparing 3-carbamoymethyl-5-methylhexanoic acid is high-yield, green, environmentally-friendly, simple and convenient, and of less pollution.

The present invention relates to crystalline modification of (3,4-dichlorophenyl)propanamide (propanil), to a process for the preparation of the same, to pesticidal mixtures and compositions comprising the crystalline modification of 5 (3,4-di-chlorophenyl)propanamide and to a method of combating weeds using said mixtures and compositions.