- Production method of n-phosphonomethyl iminodiacetic acid
-
The invention discloses a production method for pmida, comprising the following steps of (1) mixing phosphorous acid, formaldehyde and hydrochloric acid quantitatively, and heating the mixture to a set temperature; (2) dropwise adding an iminodiacetic acid-sodium salt solution into a mixed solution of phosphorous acid, formaldehyde and hydrochloric acid, and keeping the mixture warm at the set temperature until the reaction is completed, thereby obtaining a pmida suspension, wherein the molar ratio of hydrochloric acid to iminodiacetic acid-sodium salt is less than 1.1; (3) cooling the pmida suspension, crystallizing the pmida suspension, separating solids from liquid, and drying to prepare pmida. According to the production method for pmida, the iminodiacetic acid-sodium salt is dropwise added into the mixed solution of phosphorous acid, formaldehyde and hydrochloric acid, and the charging way ensures that hydrogen chloride in a reaction system is always in an excessive state relative to iminodiacetic acid so as to achieve the purposes of reducing the usage amount of hydrochloric acid and the brine wastewater quantity and improving the yield of pmida.
- -
-
Paragraph 0028; 0029
(2017/04/14)
-
- Using glycine crystallization mother liquor to produce N-phosphonomethyl glycine method (by machine translation)
-
The invention belongs to the technical field of agricultural chemicals, relates to a use of glycine crystallization mother liquor to produce N-phosphonomethyl-glycine is method for treating keratoconjunctival, the method is the mother liquor through the chemical reaction of glycine in completely converted into salt of iminodiacetic acid-containing mother liquor, and then the iminodiacetic acid salt mother liquor and chlorine methyl phosphine acid sodium salt reaction, to obtain N-phosphonomethyl iminodiacetic acid, obtained after the oxidation N-phosphonomethyl glycine. The method is well solved the difficult problem of glycine crystallization mother liquor treatment, the better use of the mother liquor in the glycine residue and its by-product iminodiacetic acid production N-phosphonomethyl glycine, three waste resource, create social benefits and economic benefits; intermediate product generated by this method without the need of separation and purification, does not need to remove inorganic salt, the reaction procedures simplified, the cost saving is even more; in addition the method of the present invention, the whole reaction process is not a large amount of waste liquid produced, also produced of non-formaldehyde, is friendly to the environment. (by machine translation)
- -
-
Paragraph 0045; 0053; 0061; 0069
(2017/01/31)
-
- Recycling method for mother liquor of N-(phosphonomethyl)iminodiacetic acid
-
The invention relates to a recycling method for mother liquor of N-(phosphonomethyl)iminodiacetic acid. According to the invention, with iminodiacetonitrile as a main raw material, through an alkaline hydrolysis process or an acidolysis and alkaline hydrolysis combined process, ammonia gas is recycled or/and monosodium diacid salt is generated by addition of ammonium salt and double decomposition reaction of deamination under heating; a qualified sodium chloride by-product is precipitated and separated through direct hydrolysis of the mother liquor of N-(phosphonomethyl)iminodiacetic acid and common-ion effect of hydrogen chloride; acidic mother liquor can be recycled; the mother liquor, the mother liquor incapable of being reused and washing water can be completely precipitated and separated through the addition of calcium hydroxide; the obtained precipitate can regenerate raw materials and products through an aqueous solution of acid or alkali; N-(phosphonomethyl)iminodiacetic acid is reused or separately synthesized; and the regenerated calcium hydroxide can be repeatedly reused. The novel recycling method provided by the invention can realize clean production of N-(phosphonomethyl)iminodiacetic acid and cyclic utilization of by-products with high added value.
- -
-
Paragraph 0034; 0035
(2017/01/19)
-
- A method for preparing pmida (by machine translation)
-
The invention provides a preparation method of N-(phosphonomethyl) iminodiacetic acid. The preparation method comprises the steps of enabling disodium iminodiacetate to react with hydrochloric acid to obtain a solution containing monosodium iminodiacetate and sodium chloride; concentrating the solution containing monosodium iminodiacetate and sodium chloride, heating and filtering to obtain a sodium chloride solid and filtrate; mixing the filtrate with hydrochloric acid and phosphorous acid, heating, then adding formaldehyde and reacting to obtain N-(phosphonomethyl) iminodiacetic acid. As monosodium iminodiacetate has relatively large solubility in water and the changes in solubility of sodium chloride along with the temperature are not obvious, sodium chloride obtained by acidification of disodium iminodiacetate by hydrochloric acid is firstly separated, so that the content of sodium chloride is reduced, the precipitation of sodium chloride in the subsequent reaction is avoided, and the reaction yield is improved; meanwhile, the viscosity of raw materials is reduced, so that the mixing of the raw materials becomes more uniform. Secondary, as sodium chloride in the system is reduced, wastewater produced by washing during separation of N-(phosphonomethyl) iminodiacetic acid is reduced. Experimental results show that the yield of N-(phosphonomethyl) iminodiacetic acid prepared by the method provided by the invention can be up to above 93%.
- -
-
Paragraph 0049
(2017/04/05)
-
- Glyphosate alkaline mother liquor processing method
-
The invention discloses a treatment method of a glyphosate alkaline mother solution, which comprises the following steps that: a hydrochloric acid is added to the mother solution to adjust the pH of the solution to 1-5 to obtain a solution A; the solution A is subjected to membrane separation to obtain a solution B and a sodium chloride solution, and the sodium chloride solution is evaporated to obtain a saturated solution; and the saturated sodium chloride solution is subjected to the Hou soda process to obtain sodium carbonate to be recycled. The treatment method is characterized in that the solution B is concentrated to make the concentration of a solute in the solution B increase to 3-10 times, i.e. a solution C, and then the appropriate amount of glycine and formaldehyde is added to the solution C, so that glyphosate and phosphorous acid in the solution C are reacted completely to obtain glyphosine and the original glyphosine in the solution C; and the glyphosine is neutralized, leached and dried and the like to obtain a glyphosine solid to be recycled. The treatment method has the advantages that the glyphosate, the glyphosine, sodium hypophosphite and the sodium chloride in the glyphosate alkaline mother solution are fully recycled, the waste is reduced, the pollution is reduced, and the utilization rate of the alkaline mother solution is improved.
- -
-
Paragraph 0028-0029
(2017/01/17)
-
- Pmida production and stock solution of phosphorus trichloride in addition to salt recycle method
-
The invention discloses a method for producing N-(phosphonomethyl)iminodiacetic acid and recycling a mother solution by phosphorus trichloride desalinization, which comprises the following steps: 1) hydrolyzing iminodiacetonitrile with a sodium hydroxide solution to obtain disodium iminodiacetate; 2) adding phosphorus trichloride to acidify the disodium iminodiacetate; 3) adding formaldehyde, heating to react to synthesize the N-(phosphonomethyl)iminodiacetic acid; 4) cooling, crystallizing, separating the solid, and drying to obtain the N-(phosphonomethyl)iminodiacetic acid product; 5) adding phosphorus trichloride into the mother solution subjected to N-(phosphonomethyl)iminodiacetic acid separation until the concentration of the hydrogen chloride is 15-30% so as to precipitate sodium chloride, and separating and taking the sodium chloride out; and 6) returning the hydrogen-chloride/phosphorous-acid-containing mother solution subjected to sodium chloride separation to the step 2) to acidify the disodium iminodiacetate. The method is simple and easy to implement, can avoid the problems of complex process and high energy consumption in the original desalinization technique for concentrating the mother solution, and can recycle excessive phosphorous acid, formaldehyde and dissolved N-(phosphonomethyl)iminodiacetic acid in the mother solution, thereby reducing the raw material consumption and enhancing the yield.
- -
-
Paragraph 0031-0036
(2017/02/09)
-
- A method for synthesizing pmida (by machine translation)
-
The invention discloses a synthesis method of N-(Phosphonomethyl) iminodiacetic acid (PMIDA) using iminodiacetonitrile as the raw material. The method comprises the following steps: using mixed acid as a hydrolytic reagent, hydrolyzing the iminodiacetonitrile in the mixed acid water solution to obtain acid salt of the iminodiacetic acid, and then performing the condensation reaction of the hydrolyzation solution with phosphorous acid and formaldehyde at the presence of hydrochloric acid to obtain the N-(Phosphonomethyl) iminodiacetic acid, wherein the mixed acid is hydrochloric acid and sulfuric acid, or hydrochloric acid and orthophosphorous acid. According to the invention, the mixed acid is used as a hydrolytic reagent; meanwhile, high temperature and high pressure are adopted to enable the hydrolyzation to be more thorough; at the same time, no waste gas is emitted; and the periodic time of the whole synthesis process is short, the operation is simple, the utilization ratio of the raw materials is high, the side product is few, energy consumption is low and the three wastes are less.
- -
-
Paragraph 0031; 0032
(2017/01/17)
-
- New process for clean production of pmida and cyclic utilization of byproducts
-
The invention relates to a new process for clean production of pmida and cyclic utilization of byproducts. According to the new process, iminodiacetonitrile serves as a main raw material, ammonia gas or/and a regenerated diacid monosodium salt are recovered by an alkaline hydrolysis or acid hydrolysis and alkaline hydrolysis coordinating process and an ammonium salt added and heating deamination double decomposition reaction, a qualified sodium chloride byproduct is precipitated and separated through the direct hydrolysis of pmida mother liquor and the common-ion effect of hydrogen chloride, acidic mother liquor can be cyclically applied mechanically, mother liquor, mother liquor, which cannot be applied mechanically, and washing water can be completely precipitated and separated through adding calcium hydroxide, raw materials and products can be regenerated from precipitates by an aqueous solution of acid or alkali, the precipitates are applied mechanically or are used for independently synthesizing the pmida, and regenerated calcium hydroxide can be repeatedly applied mechanically. According to the new process, the clean production of the pmida and the cyclic and high-added-value utilization of the byproducts can be realized.
- -
-
Paragraph 0035
(2016/12/01)
-
- A kind of pmida production equipment and production method
-
The invention provides production equipment and production method of N-phosphonomethyl aminodiacetic acid. The production method comprises the following steps of feeding phosphorous acid, suspension of iminodiacetic acid, formaldehyde and hydrochloric acid into a pipeline mixer through a first pipeline preheater, a second pipeline preheater, a third pipeline preheater and a fourth pipeline preheater respectively, and mixing; performing a condensation reaction sequentially through a pipeline reactor and a reaction kettle to obtain N-phosphonomethyl aminodiacetic acid. Compared with the prior art, in the method provided by the invention, the pipeline reactor is connected in series with the reaction kettle, and the reaction materials are preheated and enter the pipeline mixer and pipeline reactor once under control to perform a quick reaction and then enter the reaction kettle to perform a slow reaction, thereby preventing the reaction materials from staying at relatively high temperature for a long time and generating a side reaction; moreover, in the reaction kettle, the concentration of the reaction materials is relatively low, the reaction speed is low, and the reaction materials can react by use of the heat thereof after reaction in the pipeline reactor, thereby effectively increasing the retention time of the materials and improving the reaction efficiency.
- -
-
Paragraph 0005; 0046-0054
(2017/03/17)
-
- Preparing method for glyphosate
-
The invention relates to a preparing method for glyphosate and belongs to the technical field of chemical engineering. The preparing method specifically comprises the four steps of synthesis of iminodiacetic acid, preparation of pmida, preparation of glyphosate and solid and liquid separation. According to the preparing method, firstly, precious metal silver is loaded on titanium dioxide, the surface nature of titanium dioxide is influenced, electron distribution is changed, and catalytic activity is improved; then, titanium dioxide loaded with silver is loaded into activated carbon and irradiated with an ultraviolet source. The selectivity of glyphosate is greatly improved, the oxidization process of pmida is greatly shortened, the yield of glyphosate is increased to 96.3%, and the product purity can reach 97.6%; besides, the content of methyl aldehyde is low, fewer products are generated, and the requirement of the nation for environment friendliness is met.
- -
-
Paragraph 0028; 0031
(2017/04/05)
-
- METHOD FOR THE SYNTHESIS OF N-PHOSPHONOMETHYLIMINODIACETIC ACID
-
The present invention is related to a method for the synthesis of N- phosphonoalkyliminodiacetic acid or derivatives thereof comprising the steps of: a) forming a reaction mixture comprising an acid catalyst, a compound having the general formula R1 -CH2-NX-CH2-R2 and a compound having one or more P-O-P anhydride moieties, to form a compound having the general formula R1 - CH2-N-CH2(P03H2)-CH2-R2, its dehydrated forms or their derivatives, wherein - the compound of the formula R1 -CH2-NX-CH2-R2 is characterized in that: - X is -CH2-OH or -CH2-COOH; - R1 and R2 are independently selected from the group consisting of nitrile, C1 -C4 alkyl carboxylate, or are both carbonyl groups linked by means of a hydrogen substituted nitrogen atom or a C1 -C4- akyl substituted nitrogen atom; - the P-O-P anhydride comprising compound is characterized in that said anhydride moieties comprise one P atom at the oxidation state (+I II ) and one P atom at the oxidation state (+I II ) or (+V); and b) hydrolysing the reaction mixture to form N- phosphonomethyliminodiacetic acid or one of its derivatives.
- -
-
Paragraph 0080
(2014/02/15)
-
- METHOD FOR THE SYNTHESIS OF ALPHA-AMINOALKYLENEPHOSPHONIC ACID
-
The present invention is related to a new method for the synthesis of alpha-aminoalkylenephosphonic acid or its phosphonate esters comprising the steps of forming a reaction mixture by mixing a P-O-P anhydride moiety comprising compound, having one P-atom at the oxidation state (+111) and the other P-atom at the oxidation state (+111) or (+V), an aminoalkanecarboxylic acid and an acid catalyst, wherein said reaction mixture comprises an equivalent ratio of alpha-aminoalkylene carboxylic acid to P-O-P anhydride moieties of at least 0.2, and recovering the resulting alpha-aminoalkylene phosphonic acid compound or an ester thereof from the reaction mixture.
- -
-
Page/Page column 27
(2014/02/15)
-
- METHOD FOR THE MANUFACTURE OF PHOSPHONOALKYL IMINODIACETIC ACID
-
An improved method for the manufacture of phosphonoalkyl iminodiacetic acid M2PO3-X-N- (CH2COOM) 2 wherein X is a C1-6 linear or branched alkyl group; and M is selected from hydrogen, alkali, earth-alkali, ammonium and protonated amine is disclosed. The iminodiacetic acid starting material is reacted with a substantially stoichiometric amount of phosphorous acid, in the presence of a large excess of phosphoric acid to thereby yield a reaction medium insoluble reaction product (PAIDA) which can be separated from the reaction medium. In a particularly preferred approach, the phosphorous acid is prepared in situ starting from liquid P4O6.
- -
-
Page/Page column 19-20
(2011/05/11)
-
- METHOD FOR THE MANUFACTURE OF PHOSPHONOALKYL IMINODIACETIC ACIDS
-
An improved method for the manufacture of phosphonoalkyl iminodiacetic acid (PAIDA) is disclosed. The iminodiacetic acid starting material is reacted with a considerable amount, in excess of stoichiometric requirements, of phosphorous acid to thereby yield a reaction medium insoluble reaction product which can be separated from the reaction medium. In a particularly preferred approach, the phosphorous acid is prepared in situ starting from liquid P4O6.
- -
-
Page/Page column 13
(2010/12/26)
-
- Method for the Manufacture of Aminoalkylene Phosphonic Acid
-
A method for the manufacture of amino alkylcnc phosphonic acids is disclosed. Pure P4O6 is hydrolyzed in the presence of a homogeneous Brocnstcd acid catalyst whereby the pH of the reaction medium is maintained below 5 and the free water content of said reaction medium is, after the P4O6 hydrolysis has been completed, from 0 to 40 %. The required amine component can be added before, during, or in one preferred execution, after the P4O6 hydrolysis has been completed. Formaldehyde is then added and the reaction mixture containing the P4O6 hydrolysate, the amine and the formaldehyde is reacted in presence of a Broensted acid catalyst selected from homogeneous and heterogeneous species. The amino alkylene phosphonic acid reaction product can then be recovered in a manner known per sé.
- -
-
Page/Page column 9-10
(2009/11/30)
-
- Altering the crystal size distribution of N-(phosphonomethyl) iminodiacetic acid for improved filtration and product quality
-
Improved processes for preparing and crystallizing N-(phosphonomethyl)iminodiacetic acid are provided. The processes include adding N-(phosphonomethyl)iminodiacetic acid seed crystals to N-(phosphonomethyl)iminodiacetic acid reaction solutions. Provided are beds of crystallized N-(phosphonomethyl)iminodiacetic acid having improved permeability and filtration rate and reduced impurities.
- -
-
Page/Page column 4; 5; 16; 18-20
(2008/06/13)
-
- Use of a supplemental promoter in conjunction with a carbon-supported, noble-metal containing catalyst in liquid phase oxidation reactions
-
This invention relates to the use of a supplemental promoter in conjunction with a noble-metal-containing catalyst comprising a carbon support in catalyzing liquid phase oxidation reactions, a process for making of an improved catalyst comprising such a supplemental promoter, and an improved catalyst comprising such a supplemental promoter. In a particularly preferred embodiment, a supplemental promoter (most preferably bismuth or tellurium) is used in conjunction with a noble-metal-containing catalyst comprising a carbon support in a liquid phase oxidation process wherein N-(phosphonomethyl)iminodiacetic acid (i.e., “PMIDA”) or a salt thereof is oxidized to form N-(phosphonomethyl)glycine (i.e., “glyphosate”) or a salt thereof. The benefits of such a process include increased oxidation of the formaldehyde and formic acid by-products, and, consequently, decreased final concentrations of those by-products as well as other undesirable by-products, most notably N-methyl-N-(phosphonomethyl)glycine (i.e., “NMG”).
- -
-
-
- Reaction systems for making N- (phosphonomethyl) glycine compounds
-
This invention generally relates to liquid phase oxidation processes for making N-(phosphonomethyl)glycine (also known in the agricultural chemical industry as glyphosate) and related compounds. This invention, for example, particularly relates to processes wherein an N-(phosphonomethyl)iminodiacetic acid (NPMIDA) substrate (i.e., N-(phosphonomethyl)iminodiacetic acid, a salt of N-(phosphonomethyl)iminodiacetic acid, or an ester of N-(phosphonomethyl)iminodiacetic acid) is continuously oxidized to form an N-(phosphonomethyl)glycine product (i.e., N-(phosphonomethyl)glycine, a salt of N-(phosphonomethyl)glycine, or an ester of N-(phosphonomethyl)glycine). This invention also, for example, particularly relates to processes wherein an N-(phosphonomethyl)iminodiacetic acid substrate is oxidized to form an N-(phosphonomethyl)glycine product, which, in turn, is crystallized (at least in part) in an adiabatic crystallizer.
- -
-
-
- Method of preparing amino carboxylic acids
-
Process for the preparation of an N-acyl amino carboxylic acid by means of a carboxymethylation reaction. In this reaction, a reaction mixture is formed which contains a base pair, carbon monoxide, hydrogen and an aldehyde with the base pair comprising a carbamoyl compound and a carboxymethylation catalyst precursor. In a preferred embodiment, the carbamoyl compound and aldehyde are selected to yield an N-acyl amino carboxylic acid which is readily converted to N-(phosphonomethyl)glycine, or a salt or ester thereof.
- -
-
-
- Continuous process for the preparation of N-(phosphonomethyl) iminodiacetic acid
-
A process for the production of N-(phosphonomethyl)iminodiacetic acid. N-(acetyl)iminodiacetic acid is formed in a amidocarboxymethylation reactor system, into which a source of each of the following is continuously fed: (1) acetamide or an acetamide derivative, (2) formaldehyde or a formaldehyde generator or derivative, (3) a carbonylation catalyst, (4) carbon monoxide, and optionally (5) hydrogen. In turn, an amidocarboxymethylation reaction product stream, which contains N-(acetyl)iminodiacetic acid and the carbonylation catalyst, is withdrawn from the amidocarboxymethylation reactor system. The carbonylation catalyst is separated from the amidocarboxymethylation reaction product stream to recover the carbonylation catalyst and form a catalyst depleted product stream which contains N-(acetyl)iminodiacetic acid. The separated carbonylation catalyst is returned to the amidocarboxymethylation reactor system, and the N-(acetyl)iminodiacetic acid in the catalyst depleted product stream is either: (1) reacted with a source of phosphorous and a source of formaldehyde in the presence of an acid to form a phosphonomethylation reaction product stream containing N-(phosphonomethyl)iminodiacetic acid and acetic acid; or (2) deacylated and cyclized to form a 2,5-diketopiperazine, and then reacted with a source of phosphorous and a source of formaldehyde in the presence of an acid to form a phosphonomethylation reaction product stream containing N-(phosphonomethyl)iminodiacetic acid and acetic acid. Either way, the N-(phosphonomethyl)iminodiacetic acid is precipitated from the phosphonomethylation reaction product stream in the presence of acetic acid, and the precipitate is recovered to form a filtrate stream.
- -
-
-
- Use of monosodium iminodiacetic acid solutions in the preparation of N-phosphonomethyliminodiacetic acid
-
A method is described for making solution stable salts of iminodiacetic acid (IDA), useful as precursors in the manufacture of N-phosphonomethylglycine. Concentrated dialkali salts of IDA which are insoluble at temperatures below about 55° C., such as the disodium salt (DSIDA) are acidified to monoalkali salts, such as monosodium IDA (MSIDA). The resulting salts are stable in solution, and may conveniently be stored or transported in solution without recourse to dilution, heating, or similar measures.
- -
-
-
- Effect of the nature of carbon catalysts on glyphosate synthesis
-
Aqueous solutions of PMIDA (N-phosphonomethyliminodiacetic acid) were oxidized, using air, to obtain glyphosate (N-(phosphonomethyl)glycine) an active herbicide. The oxidative decarboxylation reaction was catalyzed selectively by active carbons obtained from different precursors and modified by specific thermal treatments. The activities were highly dependent upon the functional groups present on the carbon surface. Nitrogen-containing functional groups greatly enhanced the oxidation rates; these groups were either issued from the carbon precursors or introduced by thermal treatment under NH3 of active carbons. The highest rates of PMIDA oxidation were obtained using nonactivated carbons treated with NH3 at 900°C. Activities were also enhanced by thermal treatments at 900°C under N2 which eliminated the acidic sites from the carbon surface, and possibly created active basic sites.
- Pinel, Catherine,Landrivon, Emmanuel,Lini, Hedi,Gallezot, Pierre
-
p. 515 - 519
(2007/10/03)
-
- Process for the manufacture of N-phosphonomethyliminodiacetic acid
-
A process for the manufacture of N-phosphonomethyliminodiacetic acid which comprises: 1) reacting iminodiacetic acid with phosphorous acid and a source of formaldehyde in aqueous solution in the presence of concentrated sulphuric acid; 2) filtering and recovering the N-phosphonomethyliminodiacetic acid product precipitated in stage (1); 3) recovering the filtrates from stage (2) and optionally removing a proportion of the water therefrom; 4) transferring the filtrates from stage (3) to a further reaction stage in which further iminodiacetic acid is reacted with phosphorous acid and a source of formaldehyde in the presence of sulphuric acid; and thereafter 5) repeating stages (1), (2), (3) and (4) in a plurality of re-cycles.
- -
-
-
- Process for the preparation of N-substituted aminomethylphosphonic acids
-
A process for the preparation of an N-substituted aminomethylphosphonic acid comprising reacting a substituted amine, urea or carbamate substrate compound with phosphorous acid and formaldehyde in an acidic medium.
- -
-
-
- X-RAY STRUCTURAL STUDY OF ORGANIC LIGANDS OF THE COMPLEXONE TYPE. III. CRYSTAL AND MOLECULAR STRUCTURE OF PHOSPHONOMETHYLGLYCINE AND IMINODIACETIC-MONOMETHYLPHOSPHONIC ACID
-
An x-ray structural study of phosphonomethylglycine (I) and iminodiacetic-monomethylphosphonic acid (II) has been carried out (diffractometer, direct method, anisotropic method of least squares, R = 0.035 and 0.050, RW = 0.040 and 0.052 from 1712 and 1113 reflections for compounds I and II respectively).The crystals of compound I are monoclinic and those of compound II triclinic; I: a = 8.681, b = 7.981, c = 9.893 Angstroem, β = 105.77 deg, dcalc = 1.702 g/nm3, Z = 4, space group P21/c; II: a = 5.590, b = 7.422, c = 10.648 Angstroem, α = 93.12, β = 95.03, γ = 90.40 deg, dcalc = 1.716 g/cm3, Z = 2, space group .The geometric parameters of the molecules of compounds I and II are similar.Structural proof has been obtained for the first time to show that the nitrogen atom is protonated by the proton of the phosphonic acid group, and not the carboxyl group, for the Complexones I and II, containing comparing functional groups, in the crystalline state.Complexone I is obtained from Complexone II by removing one methylcarboxyl group and replacing it by a hydrogen atom.The result of this process is a change in compound I from the conformation of the molecule of compound II, directed towards the stabilization of a sterically favorable system of hydrogen bonds (HB), responsible for the similar structural motifs in the crystals of compounds I and II.This system includes HB O -H...O and N -H...O, forming dimeric ribbons, networks, and three-dimensional frameworks.In compound II, weak intramolecular HB are formed, leading to the formation of H-rings.
- Shkol'nikova, L. M.,Porai-Koshits, M. A.,Dyatlova, N. M.,Yaroshenko, G. F.,Rudomino, M. V.,Kolova, E. K.
-
p. 737 - 746
(2007/10/02)
-