CS260397B1 - Method of preparation of aldoses - Google Patents

Abstract

The purpose of the method for preparing aldoses is to improve the methods for preparing aldoses, i.e. to simplify and economize these methods of preparation. The stated purpose is achieved by adding citric acid to N-phenylglycosylamine, water and/or ethanol and a molybdate compound in a molar ratio of molybdenum with oxidation state VI to citric acid of 1: at least 4 and the reaction mixture is hydrolyzed by steam stripping. The method for preparing aldoses has applications in organic chemistry and biochemistry.

Description

260397

The invention relates to a process for the preparation of aldoses. In some methods of isolating one of the aldose precipitates, the reaction of aldoses with anilines was used, employing a different crystallization ability of the resulting N-phenylglycosylamines. N-Phenylribozylamine is isolated from a mixture of arabinose and ribose and from N-phenyllyxozylamine [V. Bílik, J. Caplovic: Chsm. 27, 547 (1973), fructose, glucose and mannose N-phenylmanzylamine [V. Bilik, K. Applicants: Chem. 28, 106 (1984)], D-glycero-L-glucohepthosis and D-glycero-L-manoheptose N-phenyl-D-glycero-L-manoheptozylamine [V. Bílik, L. Petruš: Chem. Annals 30, 359 (1976)] and L-arabinose and D-xylose N- (4-nitrophenyl) -L-arabinose amine mixtures [V. Bílik, A. Kramář: Chem. Rumors 33, 641 (1979)]. From the N-phenylglycosylamines, I can be aldose released by formaldehyde [T. Fujita, T. Sá-to: Bull. Chem. Soc. Japan 33, 353 (1960)], benzaldehyde [R. L. Whistler, J.N. Be-Miller: Methods Carbohydr. Chem. 1, 81 (1962)], by hydrolysis with steam-boiling water [V. Bílik, J. Čaplovič: Chem.Zvěsti 27, 547 (1973); V. Bílik, L. Petruš: Chem. Announcements 30, 359 (1976)], hydrolyzed by an acidic ion exchanger (CS AO no.196,996). In all these reactions, the molybdenum ions in the release processes are not required. Therefore, solutionaldoses had to be deionized before the corresponding derivatization, in particular by N-phenylglycosylamines, which increases the labor and price of the prepared aldoses. Aldoses are epimerized in weakly acidic aqueous solutions in the presence of molybdenum ions to form equilibrium! a mixture of C-2-epimeric aldoses (United Kingdom: Chem. sheets 77, 496 (1983)).

The above drawbacks are substantially hindered by the method of preparation of aldoses according to the invention, wherein the N-phenylglycosylamine, water and / or ethanol and molybdenum compound are citric acid addition moieties in the molybdenum oxidation stage VI to acid citric acid 1: at least 4, and the reaction mixture is hydrolysed by means of a vortexing technique. EXAMPLE 1 To a solution containing 25 ml of water, 2 ml of 99% wt. of acetic acid, 3 g of hexammonium heptamolybdate is added 250 g of D-glucose monohydrate. The mixture was heated to 90 ° C for 50 min. The reaction mixture is diluted with 120 ml of methanol, then with 120 ml of 96% by weight. The solution was crystallized at 23 ° C for 2 days. Crystalline D-glucose was filtered off (105 g, i.e. 42% yield as starting D-glucose).

The filtrate is treated with a 1: 1 mixture of methanol and ethanol to 500 ml of total volume, 100 ml of aniline is added and left to stand for 20 hours at 23 ° C. Crystalline N-phenyl-D-manozylamine is filtered off (80 g, ie 25% yield of D-mannose based on starting D-glucose and 43% yield, respectively, by taking into account D-glucose) and washed a 1: 1 mixture of methanol and ethanol. The obtained N-phenyl-D-manozylamine contains 4 milligrams of molybdenum in the oxidation step VI. To 500 ml of water add 80 g of N-phenyl-D-manozylamine, 35 mg of citric acid monohydrate (molar ratio of citric acid) to molybdenum in the oxidation stage VI is 4: 1) and the mixture is hydrolyzed by water vapor penetration, until 800 ml of water / aniline mixture is distilled into the preform. The D-mannose-containing solution is purified by charcoal, the filtrate is concentrated and the distillation residue is crystallized from 150 ml of methanol to give 46 g (i.e. 80% yield, based on N-phenyl). D-manozylamine) D-mannose. The mother liquor is concentrated, the residue is dissolved in 30 ml of methanol to give a second crystalline portion of D-mannose (7 g, i.e. 12.5% yield). Example 2

A mixture of 100 g of L-arabinose, 1 g of molybdic acid and 500 ml of water was heated at 95 ° C for 3 h. The solution is concentrated, the syrupy residue is dissolved in 200 ml of methanol and allowed to crystallize at 23 degrees Celsius for 24 h. Crystalline L-arabinose (60 g) is filtered off, the mother liquor is concentrated, the solvent residue is 40 ml of a 96 wt. of ethanol and water in a 7: 1 weight ratio and 15 mlaniline is added. The mixture is allowed to stand at 23 degrees Celsius for 24 h, Crystalline N-phenyl-L-ribozylamine (32 g, ie 21.5% L-ribose yield as N-phenyl-L-ribosylamine referring to starting La -Brabinose or 53.5% yield by incorporating regenerated L-arabinose is filtered off, and the N-phenyl-L-ribozylamine obtained contains 1.5 mg of molybdenum in oxidation step VI. g of N-phenyl-L-ri-butylamine, 13 mg of citric acid monohydrate (molar ratio of citric acid to molybdenum in oxidation stage VI is 4: 1) and the mixture is hydrolysed by a water vapor rinsing technique until 350 ml of the mixture is distilled into the mixture. The L-ribose-containing solution is purified with charcoal and the filtrate is concentrated to dryness to give 20 g of chromatographically pure L-bromose, and crystalline L-ribose is obtained by crystallization from 100% ethanol.

Epimerization is also inhibited at substantial lower temperatures than the aforementioned water vapor cross-linking hydrolysis method, e.g.

Claims (1)

SUBJECT Process for the preparation of aldoses from the corresponding N-phenylglycosylamines, characterized in that to the N-phenylglycosylamine, water and / or ethanol and the molybdenum compound, a molar ratio of citric acid is added. INVENTION molybdenum having an oxidation degree of VI to citric acid of 1: at least 4 and the reaction mixture is hydrolyzed by a steam-jet technique.