摘要:
Selon l'invention, on réalise des poudres à faible hygroscopicité par granulation en lit fluidisé (140) d'une solution aqueuse (1). On obtient un composé formé de grains cristallins, dont le taux d'humidité est défini et stable. L'invention s'applique notamment à des complexes organométalliques de la glycine avec un métal.
摘要:
The present invention is a method for separately collecting an optically active amino acid amide and an optically active amino acid from an aqueous solution containing the optically active amino acid amide and the optically active amino acid together with at least one member selected from the group consisting of an acid, a base and a salt: comprising a neutralization step of neutralizing an acid or a base when the aqueous solution contains the acid or the base; a desalting step of removing a salt contained in the aqueous solution and/or formed in the neutralization step; and a step of collecting the optically active amino acid amide and the optically active amino acid separately from the aqueous solution which has been desalted in the desalting step, by a process which takes advantage of a difference in solubility between the two components in an organic solvent. The desalting step is preferably performed by an electrodialysis process optionally in the state where ammonia is added to the aqueous solution. According to the present invention, an optically active amino acid amide and an optically active amino acid, which are important as intermediates in the production of pharmaceuticals, agricultural chemicals, and various industrial chemicals, can be separately collected with high efficiency by use of an organic solvent.
摘要:
The invention relates to a method of obtaining substantially-non-salified cyclic amino acids having formula (I), wherein n is a whole number selected from 2, 3 and 4 and, in particular, gabapentin (compound having formula (I) with n = 3), with a high degree of purity. The inventive method comprises a step involving the electrolysis of a solution containing an addition salt of the cyclic amino acid with a mineral acid, which serves to eliminate the anion from the mineral acid for concentrations of no more than 3 ppm.
摘要:
The invention relates to a method for producing 2-(4-N,N-dialkylamino-2-hydroxybenzoyl)benzoates of formula (I), in which the substituents R to R , independently of one another, are defined as cited in the description. Said substances are produced as follows: I. 3-N,N-dialkylaminophenol of formula (II) is reacted with phthalic anhydride of formula (III) to obtain 2-(4-N,N-dialkylamino-2-hydroxybenzoyl) benzoic acid of formula (IV) and II. said 2-(4-N,N-dialkylamino-2-hydroxybenzoyl) benzoic acid of formula (IV) that has been formed in stage I. is esterified by means of a C1-C12 alcohol or a cyclic C3-C10 alcohol in the presence of an acidic catalyst to obtain 2-(4-N,N-dialkylamino-2-hydroxybenzoyl)benzoate of formula (I). The method is characterised in that the ester of formula (I) that has been formed is purified in an additional stage III by treatment with an adsorbent and/or by distillation.
摘要:
The invention aims at providing highly concentrated aqueous solutions of N,N-dialkylglycines which have high economical advantage and are easily handleable and favorably usable in subsequent organic chemical reactions and a process for the preparation thereof. A highly concentrated aqueous solution of an N,N-dialkylglycine which contains 30 to 80 % by mass of an N,N-dialkylglycine and 0.3 to 3 % by mass of an alkali metal salt of a mineral acid can be prepared from an aqueous solution of an alkali metal salt of an N,N-dialkylglycine by conducting (i) the step of neutralizing an aqueous solution of an alkali metal salt of an N,N-dialkylglycine with a mineral acid, (ii) the step of removing water from the aqueous solution obtained in the above step to thereby concentrate the solution, and (iii) the step of conducting solid-liquid separation between an N,N-dialkylglycine solution and an alkali metal salt of the mineral acid which is precipitated from a slurry of the salt.