Ethylenediamine, purification

Malto-oligosaccharide aldonolactones react with ethylenediamine to give Ar-(2-aminoethyl)aldonamides (113-115), which have been successfully grafted onto carriers via amide linkages. The malto-oligosaccharides were produced by degradation of amylose with alpha amylase. After purification of the oligosaccharides, they were converted into the lactones by hypoiodite or electrolytic oxidation. 

Methylacrylate and ethylenediamine were obtained from the Merck. Jeffamine T-3000 was purchased from Texaco Chemical Company. Other chemicals were used as obtained from the Fluka without further purification unless otherwise noted. Solvents were dried and distilled according to literature procedures prior to use. Reactions were controlled by thin layer chromatography (TLC) on silica gel 60 F254 and spots were detected either by UV-visible light or by charging with vapor. 

The submitters employed, without purification, 98% ethylenediamine obtained from Mallinckrodt Chemical Works the checkers employed material from Eastman Organic Chemicals which was redistilled (b.p. 117-118°) before use. The amount of ethylenediamine employed is sufficient to provide three equivalents of diamine for each mole of chro-mium(II) and to neutralize any acid remaining in the chro-mium(II) perchlorate solution. 

N 13.72% ndls, mp 112°, sol in ale eth. It was prepd by reacting ethylenediamine with E=ihy I chic roform ate an d vacuum di stiiiauon purification. Its heat of combstn is 1066kcal/mol heat of formation 23lkcalyinol at const vol. 

Ethylenediamine (en) [15] Among the impurities are water, carbon dioxide, ammonia and polyethylene amines (e.g. diethylenetriamine and triethylenetetra-mine). In the recommended purification method, commercial product (98%) is shaken for about 12h with activated molecular sieves (5A, 70 gl-1), the supernatant is decanted and shaken for about 12 h with a mixture of CaO (50 gl-1) and... 

Since the presence of even 5-10% of unchanged 1-bromo-naphthalene makes purification of the naphthalene difficult, it is important that the reduction be complete before the product is isolated. With reaction conditions described in this preparation [0.100 mole of ethylenediamine, 0.0080 mole of 1-bromonaphthalono, 60 ml. (0.031 mole) of aqueous 0.5193/... 

A further method often used is the carboxymethylation developed by Bersworth.7 It converts ethylenediamine to the tetrasodium salt of edta by simultaneous addition of sodium cyanide and formaldehyde to a sodium hydroxide solution of the diamine. The success of reaction (3) depends on the concurrent and complete removal of the ammonia liberated during the reaction. The eventual by-products, containing less than four acetic groups, can be separated from Na4edta and returned to the reaction mixture. The process can be performed continuously. In the case of nta, the salt Na3nta-H20 is obtained after purification of the reaction product. 

Levo iodide. The Zeyo-tris(ethylenediamine) cobalt (III) chloride d-tartrate remaining in the solution above is treated with concentrated ammonia solution (0.5 ml.) and the mixture is heated to about 80°. Solid sodium iodide (35 g.) is stirred in and the whole cooled in ice. The impure levo iodide is filtered off and washed with ice-cold 30% sodium iodide (25 ml.) and then with alcohol and air-dried, resulting in a yield of 27 g. Purification is effected by stirring the whole of the crude material into 65 ml. of water heated to 50°. The racemate remains undissolved and is filtered off. Sodium iodide (10 g.) is added to the warm filtrate (50°) and crystallization allowed to take place. After cooling in ice the solid is filtered, washed with ethanol and then acetone, and air-dried. The yield is 18 g. (26%), and [a]D = -90°. Anal. Calcd. for [Co(en)3]I3-H20 C, 11.26 H, 4.11. Found C, 11.43 H, 4.01. 

Various procedures for the purification of specific amine-boranes have been reported.12 Ethylenediamine-bisborane can be purified conveniently by aqueous extraction to remove water-soluble impurities. The crude product obtained from the tetrahydrofuran solution is ground to a fine powder in a mortar and added in small portions, with stirring, to about 75 ml. of water which has been cooled in an ice-water bath. Foaming may occur during this treatment. The white crystalline solid which does not dissolve is collected by filtration through a coarse-fritted-glass funnel and washed several times with small portions of cold water (about 5°C.). The final wash filtrate should be neutral toward pH paper. The product is dried by... 

Werner1 resolved the tris(ethylenediamine)rhodium(III) ion both with sodium-3-nitro-(+)-camphor and with (+)-tartrate as resolving agents. Both methods, however, suffer from disadvantages. The solubility of the diastereoisomer (—)D-[Rh(en) 3] - (3-nitro-(-(-)-camphor)3 precipitated by the first method is so low that purification by recrystallization is impossible. On the other hand, the solubilities of the diastereoisomeric chloride (-b)-tartrates used in the second method are of the same order of magnitude, so that the solution has to be seeded with a crystal of (—)D-[Rh(en)3] Cl (+)-tart -aq. The (+)D form of the chloride (+)-tartrate is not obtained in an optically pure condition. Furthermore, the yields of both methods are low because of the many operations needed for obtaining the stereoisomers of the chloride. By the present method (—)D-[Rh(en)3] + is precipitated as the double salt Li (—)D-[Rh(en)3] (+)-tart 2-3H20, which is purified before conversion to the chloride. The (-bichloride is precipitated from the mother liquor by the addition of hydrochloric acid and ethanol. 

These reactions were reported to give inconsistent results1. Purification of the phenyliodo-niobenzoates by rccrystallization from water in the presence of disodium ethylenediamine-tetraacetate gave the monohydrates that reacted reproducibly with the ditellurium compounds2. 

The bromohydrin is then quantitatively converted to the THP ether, which is added to LiC=CH-ethylenediamine complex in dimethyl sulfoxide to give VII in very high yield. No purification is required in either of these steps. A shorter synthesis of 9-decyn-l-ol (IX) was subsequently developed. An acetylene "zipper" isomerization (42) with sodio-1,3-diaminopropane is used to convert either 3-decyn-l-ol (VIII) or 2-decyn-l-ol into the terminal alkynol IX. Both of these starting alkynols are commercially available and the saving in labor is advantageous for moderate scale production. 

A solution of 20.8 ml of 1.0 M Bis(trimethylsilyl)amide in THF lithium was added to an ice-cooled solution of the Step 1 product (18.9 mmol) dissolved in 20 ml THF followed by ethyl bromoacetate (94.5 mmol) and then stirred 30 minutes. The mixture was further treated with 10 ml ethylenediamine, then stirred an additional 30 minutes, and finally concentrated. The residue was dissolved in CH2C12, then washed with dilute HC1, dried with Na2S04, and reconcentrated. The residue was redissolved in 25 ml methyl alcohol and treated with 50 ml 1.0 M NaOH. Methyl alcohol was then removed and the basic solution extracted three times with 100 ml with CH2C12. The aqueous layer was acidified with 1.0M HC1 to pH 1 and further extracted with CH2C12. Organic extracts were dried with Na2S04, filtered, concentrated, and the product isolated in 98%. The product was used directly in the next step without additional purification. 

Tris(ethylenediamine)pIatinum(IV) chloride was first reported by A. Werner in 1917. Several variations of his method have been used, but basically the preparation from platinum involves three steps (1) the preparation of the hexachloroplatinic(IV) acid, (2) the preparation of the crude tris(ethylenediamine)platinum(IV) chloride, and (3) purification. The following procedure is a modification of Werner s method. 

All solutions were prepared from reagent grade chemicals and solvents without further purification. Two of the new ligands which were tested for the Pfeiffer effect, 2-(2-pyridyl)-benzimidazoline and 2-(2-pyridyl)-imidazoline, were prepared by the method of Walter and Freiser 18). The other ligand which had to be synthesized, (ethanediylidenetetra-thio)tetraacetate (ETTA), was prepared by the method of Longo et al. 12). Tris(ethylenediamine)nickel(II) chloride was prepared by the method of State 17). Bis(salicylidene)triethylenetetramine alumi-num(III) iodide [A1(TS2)]I was prepared by the method of Das Sarma and Bailar 6). 

One hundred grams (0.64 mole) of crude 3-(ethoxymethylene)-2,4-pentanedione (procedure A) is dissolved in 1 L of absolute ethanol in a 2-L Erlenmeyer flask. Absolute ethanol (500 mL) containing 19.2 g (0.32 mole) of freshly distilled (from KOH) anhydrous ethylenediamine is added dropwise over a 30-minute period. An immediate reaction is observed to occur with the formation of a white precipitate. The solution is then filtered and the fine white crystalline material is collected by filtration, washed with absolute ethanol and diethyl ether, and dried in vacuo over P4O10 for several hours. The yield is 72 g (0.26 mole, 80%). The checkers obtained a 55% yield. Tlris material is suitable for use without further purification. Anal. Calcd. for C14H20N2O4 C. 60.0 H, 7.15 N, 10.0. Found C, 60.51 H, 7.21 N, 9.81. 

Methods for the preparation and purification of salts of the dimeric complex ions di-/i-hydroxo-bis[tetraamminechromium(III)] and di-p-hydroxo-bis [bis-(ethylenediamine)chromium(III)] and of the two corresponding cobalt(III) species are presented. The two ammine complex dimers are isolated as bromide and perchlorate salts. The two ethylenediamine complexes are isolated as dithionate, bromide, chloride, and perchlorate salts. All four dimers have been obtained by heating the corresponding cis-aquahydroxo complexes as the dithionate salts. 

To a slurry of 25.9 g (0.0715 mole) of freshly prepared Na3[(Go(003)3] 3H20 in 30 mL of water is added 12.65 g (0.0715 mole) of ethylenediamine-V,A -diacetic acid, and the solution is heated to 50° with stirring for 10 minutes. Ten milliliters of concentrated HCl diluted to 30 mL is added. The solution is filtered and cooled in an ice bath. The product is precipitated by the slow (20 min) addition of 100 mL absolute ethanol to the stirred solution. The dark-purple complex is filtered, washed with 50% aqueous ethanol and ethanol and air-dried. The total yield is 16.4 g (67%). The crude product is used without further purification in the synthesis below. A single recrystallization from ethanol-water gives a pure product. Ana/. Calcd. for Na[CoC6HioN207] I.5H2O C, 24.50 H, 3.82 N, 8.16. Found C, 24.64 H, 3.79 N, 8.17. 

Lithium acetylide, ethylenediamine complex is purchased from Aldrich Chemical Company, Inc. and used without purification. 

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