DIMETHYLPIPERAZINE (DMETLPPERAZN)
DIMETHYLPIPERAZINE (DMETLPPERAZN)
CAS NO: 106-58-1
SYNONYMS: 1,4-dimethylpiperazine-2,3-dione; 59417-06-0; 1,4-Dimethyl-2,3-piperazinedione; N,N’-dimethyl-piperazine-2,3-dione; NSC281685; Dimethyldiketopiperazin; SCHEMBL717518; CTK1H0920; DTXSID90314244; WWBHDWHAIVWDMT-UHFFFAOYSA-N; ZINC5395677; 1,4-dimethyl-piperazine-2,3-dione; SALOR-INT L169811-1EA; 8846AB; ANW-60332; AKOS006276164; MCULE-9741955103; NSC-281685; AX8232816; DB-009143; TC-149077; FT-0743303; ST24036855; 417D060; A832307;2,6-Dimethylpiperazine; 108-49-6; Piperazine, 2,6-dimethyl-; 3,5-dimethylpiperazine; IFNWESYYDINUHV-UHFFFAOYSA-N; 2,6-Dimethylpiperazine, 98%; trans-2,6-dimethylpiperazine; 2,6-dimethyl-piperazine; 2,6-DIMETHYL PIPERAZINE; (2,6-cis-dimethyl)piperazine; NSC49197; EINECS 203-588-9;NSC 49197;PubChem8571;2,6 dimethylpiperazine;2,6-dimehtylpiperazine;Piperazine,6-dimethyl-;ACMC-1BOLO;2,6-di-methylpiperazine; 3,5-dimethyl-piperazine;ACMC-209fn4;SCHEMBL190032; 2,6-Dimethylpiperazine, 97%; CTK3J3415; DTXSID70883302; EBD14684; ANW-75092; MFCD07772435; NSC-49197; AKOS009156488; AM81382; CS-W013629; MCULE-5745545417; RTC-020278; TRA0030420; TRA0048158; TRA0096773; KS-0000052V; AK-32816; AS-10841; SC-00302; DB-016110; DB-069985; ST2419182; FT-0623896; EN300-59818; M-3904; 655D481; A801885;W-108715; dimetilpiperazin; di metil; piperazin; di-metil piperazin; dimetilpiperazine; di metil; piperazine; di-metil piperazine; pipperazin; piperazine; pipperazine; di-methil piperazin; dimethilpiperazine; di methil; piperazine; di-methil piperazine; di-methiyl piperazin; dimethiylpiperazine; di methiyl; piperazine; di-methiyl piperazine; dimetilpipperazin; di-metil pipperazin; dimetilpipperazine; di metil; pipperazine; di-metil pipperazine; dimethilpipperazin; di-methil pipperazin; dimethilpipperazine; di methil; pipperazine; di-methil pipperazine; dimethypipperazin; di-methyl pipperazin; dimethylpipperazine; di methyl; pipperazine; di-methyl pipperazine; dimethiylpipperazin; di-methiyl pipperazin; dimethiylpipperazine; di methiyl; pipperazine; di-methiyl pipperazine; metilpiperazin; metil; piperazin; metil piperazin; metilpiperazine; metil; piperazine; metil piperazine; pipperazin; piperazine; pipperazine; methil piperazin; methilpiperazine; methil; piperazine; methil piperazine; methiyl piperazin; methiylpiperazine; methiyl; piperazine; methiyl piperazine; metilpipperazin; metil pipperazin; dimetilpipperazine; di metil; pipperazine; metil pipperazine; methilpipperazin; methil pipperazin; methilpipperazine; methil; pipperazine; methil pipperazine; methypipperazin; methyl pipperazin; methylpipperazine; methyl; pipperazine; di-methyl pipperazine; dimethiylpipperazin; methiyl pipperazin; methiylpipperazine; methiyl; pipperazine; methiyl pipperazine; dimethylpiperazine; di methyl piperazine; di-methyl piperazine; dimethylpipperazine; di methyl pipperazine; di-methyl pipperazine; dimethiylpiperazine; di methiyl piperazine; di-methiyl piperazine; dimethiylpipperazine; di methiyl pipperazine; di-methiyl pipperazine; dimetylpiperazine; di metyl piperazine; di-metyl piperazine; dimetylpipperazine; di metyl pipperazine; di-metyl pipperazine; dimetyilpiperazine; di metyil piperazine; di-metyil piperazine; dimetyilpipperazine; di metyil pipperazine; di-metyil pipperazine; dimethylpiperazine; di methyl piperazine; di-methyl piperazine; dimethylpipperazine; di methyl pipperazine; di-methyl pipperazine; dimetlpiperazine; di metl piperazine; di-metl piperazine; dimetlpipperazine; di metl pipperazine; di-methl pipperazine; dimethiylpiperazin; di methiyl piperazin; di-methiyl piperazin; dimethiylpipperazin; di methiyl pipperazin; di-methiyl pipperazie; dimetylpiperazin; di metyl piperazin; di-metyl piperazie; dimetylpipperazin; di metyl pipperazin; di-metyl pipperaze; dimetyilpiperazin; di metyil piperazin; di-metyil piperazie; dimetyilpipperazin; di metyil pipperazin; di-metyil pipperazie; dimethylpiperazin; di methyl piperazin; di-methyl piperazin; dimethylpipperazin; di methyl pipperazin; di-methyl pipperazine; dimethylpiperozone; di methyl piperozone; di-methyl piperozone; dimethylpipperzozone; di methyl pipperozone; di-methyl pipperozone; dimethiylpiperozone; di methiyl piperozone; di-methiyl piperozone; dimethiylpiperozone; di methiyl piperozone; di-methiyl piperozone; dimetylpiperozone; di metyl piperozone; di-metyl piperozone; dimetylpiperozone; di metyl piperozone; di-metyl piperozone; dimetyilpiperozone; di metyil piperozone; di-metyil piperozone; dimetyilpiperozone; di metyil piperozone; di-metyil piperozone; dimethylpiperozone; di methyl piperozone; di-methyl piperozone; dimethylpiperozone; di methyl piperozone; di-methyl piperozone; dimetlpiperozonne; di metl piperozonne; di-metl piperozonne; dimetlpiperozonne; di metl pipperaziane; di-methl pipperozonne; dimetlpiperazine; di metl piperazine; di-metl piperazine; dimetlpipperazine; di metl pipperazine; di-methl pipperazine; DIMETILPIPERAZIN; DI METIL; PIPERAZIN; DI-METIL PIPERAZIN; DIMETILPIPERAZINE; DI METIL; PIPERAZINE; DI-METIL PIPERAZINE; PIPPERAZIN; PIPERAZINE; PIPPERAZINE; DI-METHIL PIPERAZIN; DIMETHILPIPERAZINE; DI METHIL; PIPERAZINE; DI-METHIL PIPERAZINE; DI-METHIYL PIPERAZIN; DIMETHIYLPIPERAZINE; DI METHIYL; PIPERAZINE; DI-METHIYL PIPERAZINE; DIMETILPIPPERAZIN; DI-METIL PIPPERAZIN; DIMETILPIPPERAZINE; DI METIL; PIPPERAZINE; DI-METIL PIPPERAZINE; DIMETHILPIPPERAZIN; DI-METHIL PIPPERAZIN; DIMETHILPIPPERAZINE; DI METHIL; PIPPERAZINE; DI-METHIL PIPPERAZINE; DIMETHYPIPPERAZIN; DI-METHYL PIPPERAZIN; DIMETHYLPIPPERAZINE; DI METHYL; PIPPERAZINE; DI-METHYL PIPPERAZINE; DIMETHIYLPIPPERAZIN; DI-METHIYL PIPPERAZIN; DIMETHIYLPIPPERAZINE; DI METHIYL; PIPPERAZINE; DI-METHIYL PIPPERAZINE; METILPIPERAZIN; METIL; PIPERAZIN; METIL PIPERAZIN; METILPIPERAZINE; METIL; PIPERAZINE; METIL PIPERAZINE; PIPPERAZIN; PIPERAZINE; PIPPERAZINE; METHIL PIPERAZIN; METHILPIPERAZINE; METHIL; PIPERAZINE; METHIL PIPERAZINE; METHIYL PIPERAZIN; METHIYLPIPERAZINE; METHIYL; PIPERAZINE; METHIYL PIPERAZINE; METILPIPPERAZIN; METIL PIPPERAZIN; DIMETILPIPPERAZINE; DI METIL; PIPPERAZINE; METIL PIPPERAZINE; METHILPIPPERAZIN; METHIL PIPPERAZIN; METHILPIPPERAZINE; METHIL; PIPPERAZINE; METHIL PIPPERAZINE; METHYPIPPERAZIN; METHYL PIPPERAZIN; METHYLPIPPERAZINE; METHYL; PIPPERAZINE; DI-METHYL PIPPERAZINE; DIMETHIYLPIPPERAZIN; METHIYL PIPPERAZIN; METHIYLPIPPERAZINE; METHIYL; PIPPERAZINE; METHIYL PIPPERAZINE; DIMETHYLPIPERAZINE; DI METHYL PIPERAZINE; DI-METHYL PIPERAZINE; DIMETHYLPIPPERAZINE; DI METHYL PIPPERAZINE; DI-METHYL PIPPERAZINE; DIMETHIYLPIPERAZINE; DI METHIYL PIPERAZINE; DI-METHIYL PIPERAZINE; DIMETHIYLPIPPERAZINE; DI METHIYL PIPPERAZINE; DI-METHIYL PIPPERAZINE; DIMETYLPIPERAZINE; DI METYL PIPERAZINE; DI-METYL PIPERAZINE; DIMETYLPIPPERAZINE; DI METYL PIPPERAZINE; DI-METYL PIPPERAZINE; DIMETYILPIPERAZINE; DI METYIL PIPERAZINE; DI-METYIL PIPERAZINE; DIMETYILPIPPERAZINE; DI METYIL PIPPERAZINE; DI-METYIL PIPPERAZINE; DIMETHYLPIPERAZINE; DI METHYL PIPERAZINE; DI-METHYL PIPERAZINE; DIMETHYLPIPPERAZINE; DI METHYL PIPPERAZINE; DI-METHYL PIPPERAZINE; DIMETLPIPERAZINE; DI METL PIPERAZINE; DI-METL PIPERAZINE; DIMETLPIPPERAZINE; DI METL PIPPERAZINE; DI-METHL PIPPERAZINE; DIMETHIYLPIPERAZIN; DI METHIYL PIPERAZIN; DI-METHIYL PIPERAZIN; DIMETHIYLPIPPERAZIN; DI METHIYL PIPPERAZIN; DI-METHIYL PIPPERAZIE; DIMETYLPIPERAZIN; DI METYL PIPERAZIN; DI-METYL PIPERAZIE; DIMETYLPIPPERAZIN; DI METYL PIPPERAZIN; DI-METYL PIPPERAZE; DIMETYILPIPERAZIN; DI METYIL PIPERAZIN; DI-METYIL PIPERAZIE; DIMETYILPIPPERAZIN; DI METYIL PIPPERAZIN; DI-METYIL PIPPERAZIE; DIMETHYLPIPERAZIN; DI METHYL PIPERAZIN; DI-METHYL PIPERAZIN; DIMETHYLPIPPERAZIN; DI METHYL PIPPERAZIN; DI-METHYL PIPPERAZINE; DIMETHYLPIPEROZONE; DI METHYL PIPEROZONE; DI-METHYL PIPEROZONE; DIMETHYLPIPPERZOZONE; DI METHYL PIPPEROZONE; DI-METHYL PIPPEROZONE; DIMETHIYLPIPEROZONE; DI METHIYL PIPEROZONE; DI-METHIYL PIPEROZONE; DIMETHIYLPIPEROZONE; DI METHIYL PIPEROZONE; DI-METHIYL PIPEROZONE; DIMETYLPIPEROZONE; DI METYL PIPEROZONE; DI-METYL PIPEROZONE; DIMETYLPIPEROZONE; DI METYL PIPEROZONE; DI-METYL PIPEROZONE; DIMETYILPIPEROZONE; DI METYIL PIPEROZONE; DI-METYIL PIPEROZONE; DIMETYILPIPEROZONE; DI METYIL PIPEROZONE; DI-METYIL PIPEROZONE; DIMETHYLPIPEROZONE; DI METHYL PIPEROZONE; DI-METHYL PIPEROZONE; DIMETHYLPIPEROZONE; DI METHYL PIPEROZONE; DI-METHYL PIPEROZONE; DIMETLPIPEROZONNE; DI METL PIPEROZONNE; DI-METL PIPEROZONNE; DIMETLPIPEROZONNE; DI METL PIPPERAZIANE; DI-METHL PIPPEROZONNE; DIMETLPIPERAZINE; DI METL PIPERAZINE; DI-METL PIPERAZINE; DIMETLPIPPERAZINE; DI METL PIPPERAZINE; DI-METHL PIPPERAZINE
A new hydrogen storage system based on the hydrogenation and dehydrogenation of nitrogen heterocyclic compounds, employing a single iridium catalyst, has been developed. Efficient hydrogen storage using relatively small amounts of solvent compared with previous systems was achieved by this new system. Reversible transformations between 2,5‐dimethylpyrazine and 2,5‐dimethylpiperazine, accompanied by the uptake and release of three equivalents of hydrogen, could be repeated almost quantitatively at least four times without any loss of efficiency. Furthermore, hydrogen storage under solvent‐free conditions was also accomplished.
A METHOD FOR PREPARING 1,4-DIMETHYLPIPERAZINE WHICH COMPRISES: (A) ADDING A SOLUTION OF PIPERAZINE IN AN INERT SOLVENT TO AT LEAST ABOUT A 10% EXCESS OF FORMALDEHYDE IN AN INERT SOLVENT TO THEREBY OBTAIN 1,4-PIPERAZINEDIMETHANOL, SAID PIPERAZINE CONSTITUTING LESS THAN ABOUT 18 WT. PERCENT OF THE REACTION MIXTURE; AND (B) HYDROGENATING THE 1,4-PIPERAZINEDIMETHANOL TO 1,4DIMETHYLPIPERAZINE EMPLOYING A METALLIC HYDROGENATION CATALYST AT A TEMPERATURE OF FROM ABOUT 50* TO ABOUT 200*C.
(Cl. 260-268) This invention relates to the production of dimethylpiperazine. More particularly, this invention relates to the production of 1,4-dimethylpiperazine from piperazine, formaldehyde and hydrogen Heretofore 1,4-dimethylpiperazine has been prepared by the methylation of piperazine according to the procedure described by ‘Eschweiler [Ber. 38, 880 (1905)] or modifications of that procedure. These prior art procedures suffer from two serious disadvantages. First, large excesses of formaldehyde and formic acid are employed. As a result of the use of an excess of formic acid, the desired product is present in the reaction mixture as the formate salt and elaborate separation procedures must be employed to obtain the pure product.
Second, in the methylation of a polyamine such as piperazine, there is a tendency for the polyamine and formaldehyde to form a polymer. A new process for the production of 1,4-dimethylpiperazine which overcomes the disadvantages of the prior art processes has now been discovered. This process is a two-step process in which a solution of piperazine in a suitable solvent is added to a slight excess of formaldehyde and this reaction mixture, comprising piperazinedimethanol, is then hydrogenated over a metallic hydrogenation catalyst to produce the desired 1,4-dimethylpiperazine. Excellent yields have been obtained by the use of this process.
Since there is no formic acid or other acid present in the reaction system, the 1,4-dimethylpiperazine is present in the product mixture in the free state. The dimethylpiperazine can thus be separated from the reaction mixure by any suitable means, such as, for example, distillation. In order to avoid the formation of a polymer during the reaction between the piperazine and formaldehyde, the piperazine should be added to the formaldehyde rather than the reverse. Also, the reaction mixture should be well stirred and about a excess of formaldehyde should be emploeyd. A larger excess of formaldehyde may be used if desired; however, more formaldehyde is not necessary. We have also discovered that if the piperazine concentration in the reaction mixture exceeds about 18 wt. percent, a polymer will be formed regardless of whether or not the other precautions are observed. Accordingly, piperazine should constitute less than about 18 wt. percent of the total reaction mixture.
Both the piperazine and formaldehyde should be in solution in a suitable solvent. Formaldehyde may be employed as a formalin solution, in which event no additional solvent for the formaldehyde is necessary. The formaldehyde may also be employed in any other of its forms.Suitable solvents for this step of the process are those inert solvents in which both piperazine and 1,4-piperazinedimethanol are soluble. The lower aliphatic alcohols, such as, for example, methanol, ethanol and propanol are excellent solvents for this reaction. Other suitable solvents include, for example, glycol monoand diethers, dioxane, lower tertiary amines and water. The reaction proceeds quite readily at ambient temperatures of around 20 to 25 C., or higher temperatures may be employed if desired. The upper temperature limit is the boiling point of the solvent unless a closed system is employed and the reaction is run under pressure. A lCC temperature of about 50 C. has been found to be particularly advantageous. The solution obtained from the first step in the process may then be hydrogenated directly but is preferably filtered prior to hydrogenation. The hydrogenation may be conducted at a temperature within the range of about 50 to about 200 C. at a pressure sufficient to keep the components in the liquid state. Such a pressure is within the range of about 50 to about 3000 p.s.i.g. In conducting the hydrogenation step, a metallic hydrogenation catalyst is employed. Examples of suitable catalysts are well known to those skilled in the art.
Such catalysts include, for example, platinum, nickel and copper-chromium oxide catalysts. We have found nickelcopper-chromium catalysts to be particularly effective. Catalysts of this type will consist of 44 to 94 atom percent nickel, 5 to 55 atom percent copper and 1 to 5 atom percent chromium. A specific preferred catalyst is one consisting of nickel oxide, 22% cupric oxide and 3% chromic oxide. The results from a series of runs in which the first step of the process was conducted under various conditions are summarized in Table I. The purpose of these runs was to study polymer formation, and the products were allowed to stand for several months. In these reactions the formaldehyde was employed as a formalin solution and the solvent used for the piperazine was methanol.
In a typical run, the hydrogenation step of the process was conducted in the following manner. The reaction mixture from the first step, comprising 1,4-piperazinedimethanol, was filtered and hydrogenated using a nickel-copper-chromia catalyst comprising 75% nickel oxide, 22% cupric oxide and 3% chromic oxide at a temperature of C., and a pressure of 2500 p.s.i.g. using a 20 mol percent excess of hydrogen. The hydrogenated crude product was then distilled to yield 1,4-dimethylpiperazine of high purity. The over-all yield of l,4-dimethylpiperazine was 88.7 mol percent based on piperazine.As stated hereinabove, the 1,4-dimethylpiperazine product is present in the hydrogenated reaction mixture in the free state and may be separated from the mixture by any suitable means.
Having thus described our invention what is claimed is: 1. A method for preparing 1,4-dimethylpiperazine which comprises: (A) adding a solution of piperazine in an inert solvent to at least about a 10% excess of formaldehyde in an inert solvent to thereby obtain 1,4-piperazinedimethanol, said piperazine constituting less than about 18 wt. percent of the reaction mixture; and (B) hydrogenating the 1,4-piperazinedimethano1 to 1,4 dimethylpiperazine employing a metallic hydrogenation catalyst at a temperature of from about 50 to about 200 C. and a pressure of from about 50 to about 3000 p.s.i.g.,
2. A method as in claim 1 wherein the inert solvent is a lower aliphatic alcohol selected from the group consisting of methanol, ethanol and propanol and the metallic hydrogenation catalyst is a nickel-copper-chromia catalyst. 3. A method for preparing 1,4-dimethylpiperazine which comprises: (A) adding a methanolic solution of piperazine to at least about a 10% excess of formalin solution at a temperature of from about 20 to about 50 C. to thereby obtain 1,4-piperazinedimethanol, said piperazine constituting less than about 18 wt. percent of the reaction mixture; and l (B) hydrogenating the 1,4-piperazinedimethanol to 1,4-dimethylpiperazine employing a nickel-copper- 5 chromia hydrogenation catalyst at a temperature of from about 50 to about 200 C. and a pressure of from about 50 to about 3000 p.s.i.g.
Bis(N,N’-dimethylpiperazine)tetra[copper(I) iodide] is a porous and photoluminescent metal-organic framework (MOF) composed of copper(I) iodide and N,N’-dimethylpiperazine. American Elements can produce most materials in high purity and ultra high purity (up to 99.99999%) forms and follows applicable ASTM testing standards; a range of grades are available including Mil Spec (military grade), ACS, Reagent and Technical Grade, Food, Agricultural and Pharmaceutical Grade, Optical Grade, USP and EP/BP (European Pharmacopoeia/British Pharmacopoeia). We can also produce materials to custom specifications by request, in addition to custom compositions for commercial and research applications and new proprietary technologies. Typical and custom packaging is available, as is additional research, technical and safety (MSDS) data.
More particularly, this invention relates to the production of 1,4-dimethylpiperazine from piperazine, formaldehyde and hydrogen. Heretofore 1,4-dimethylpiperazine has been prepared by the methylation of piperazine according to the procedure described by ‘Eschweiler [Ber. 38, 880 (1905)] or modifications of that procedure. These prior art procedures suffer from two serious disadvantages. First, large excesses of formaldehyde and formic acid are employed. As a result of the use of an excess of formic acid, the desired product is present in the reaction mixture as the formate salt and elaborate separation procedures must be employed to obtain the pure product. Second, in the methylation of a polyamine such as piperazine, there is a tendency for the polyamine and formaldehyde to form a polymer.
A new process for the production of 1,4-dimethylpiperazine which overcomes the disadvantages of the prior art processes has now been discovered. This process is a two-step process in which a solution of piperazine in a suitable solvent is added to a slight excess of formaldehyde and this reaction mixture, comprising piperazinedimethanol, is then hydrogenated over a metallic hydrogenation catalyst to produce the desired 1,4-dimethylpiperazine. Excellent yields have been obtained by the use of this process. Since there is no formic acid or other acid present in the reaction system, the 1,4-dimethylpiperazine is present in the product mixture in the free state. The dimethylpiperazine can thus be separated from the reaction mixure by any suitable means, such as, for example, distillation.
The reaction mixture from the first step, comprising 1,4-piperazinedimethanol, was filtered and hydrogenated using a nickel-copper-chromia catalyst comprising 75% nickel oxide, 22% cupric oxide and 3% chromic oxide at a temperature of C., and a pressure of 2500 p.s.i.g. using a 20 mol percent excess of hydrogen. The hydrogenated crude product was then distilled to yield 1,4-dimethylpiperazine of high purity. The over-all yield of l,4-dimethylpiperazine
was 88.7 mol percent based on piperazine.As stated hereinabove, the 1,4-dimethylpiperazine product is present in the hydrogenated reaction mixture in the free state and may be separated from the mixture by any suitable means.
Having thus described our invention what is claimed is:
1. A method for preparing 1,4-dimethylpiperazine which comprises: (A) adding a solution of piperazine in an inert solvent to at least about a 10% excess of formaldehyde in an inert solvent to thereby obtain 1,4-piperazinedimethanol, said piperazine constituting less than about 18 wt. percent of the reaction mixture; and (B) hydrogenating the 1,4-piperazinedimethano1 to 1,4 dimethylpiperazine employing a metallic hydrogenation catalyst at a temperature of from about 50 to about 200 C. and a pressure of from about 50 to about 3000 p.s.i.g.
2. A method as in claim 1 wherein the inert solvent is a lower aliphatic alcohol selected from the group consisting of methanol, ethanol and propanol and
the metallic hydrogenation catalyst is a nickel-copper-chromia catalyst. 3. A method for preparing 1,4-dimethylpiperazine which comprises:
(A) adding a methanolic solution of piperazine to at least about a 10% excess of formalin solution at a temperature of from about 20 to about 50 C. to thereby obtain 1,4-piperazinedimethanol, said piperazine constituting less than about 18 wt. percent of the reaction mixture; and l (B) hydrogenating the 1,4-piperazinedimethanol to 1,4-dimethylpiperazine employing a nickel-copper- 5 chromia hydrogenation catalyst at a temperature of from about 50 to about 200 C. and a pressure of from about 50 to about 3000 p.s.i.g.
A new hydrogen storage system based on the hydrogenation and dehydrogenation of nitrogen heterocyclic compounds, employing a single iridium catalyst, has been developed. Efficient hydrogen storage using relatively small amounts of solvent compared with previous systems was achieved by this new system. Reversible transformations between 2,5‐dimethylpyrazine and 2,5‐dimethylpiperazine, accompanied by the uptake and release of three equivalents of hydrogen, could be repeated almost quantitatively at least four times without any loss of efficiency. Furthermore, hydrogen storage under solvent‐free conditions was also accomplished.
Tek bir iridyum katalizörü kullanan azot heterosiklik bileiklerin hidrojenasyonuna ve dehidrojenasyonuna dayanan yeni bir hidrojen depolama sistemi gelitirilmitir. Bu yeni sistem, önceki sistemlere kyasla nispeten az miktarda çözücü kullanlarak verimli hidrojen depolamas saland. 2,5 ‐ dimetilpirazin ve 2,5 ‐ dimetilpiperazin arasndaki tersinir dönüümler, üç edeer hidrojenin alnmas ve serbest braklmas ile birlikte, herhangi bir verimlilik kayb olmakszn neredeyse nicel olarak en az dört kez tekrarlanabilir. Ayrca çözücü içermeyen koullar altnda hidrojen depolama da gerçekletirildi.
Bu bulu dimetilpiperazin üretimi ile ilgilidir. Daha özel olarak, bu bulu piperazin, formaldehit ve hidrojenden 1,4-dimetilpiperazin üretimi ile ilgilidir.
imdiye kadar 1,4-dimetilpiperazin, piperazinin metilasyonu ile ‘Eschweiler [Ber. 38, 880 (1905)] veya bu prosedürün modifikasyonlar. Önceki teknik prosedürleri iki ciddi dezavantaja sahiptir. lk olarak, ar miktarda formaldehit ve formik asit kullanlr. Fazla formik asit kullanmnn bir sonucu olarak, arzu edilen ürün, reaksiyon karmnda format tuzu olarak bulunur ve saf ürünü elde etmek için ayrntl ayrma prosedürleri kullanlmaldr. kincisi, piperazin gibi bir poliaminin metilasyonunda, poliamin ve formaldehitin bir polimer oluturma eilimi vardr.Önceki teknik ilemlerinin dezavantajlarnn üstesinden gelen 1,4-dimetilpiperazin üretimi için yeni bir ilem kefedilmitir.
Bu ilem, uygun bir çözücü içinde bir piperazin çözeltisinin biraz fazla formaldehite ilave edildii ve piperazinedimetanol içeren bu reaksiyon karmnn, daha sonra istenen 1,4- dimetilpiperazin. Bu ilem kullanlarak mükemmel verim elde edilmitir. Reaksiyon sisteminde formik asit veya baka bir asit bulunmadndan, 1,4-dimetilpiperazin ürün karmnda serbest halde bulunur. Dimetilpiperazin böylece reaksiyon karmndan, örnein damtma gibi herhangi bir uygun yolla ayrlabilir. Piperazin ve formaldehit arasndaki reaksiyon srasnda bir polimer oluumundan kaçnmak için, piperazin, tersine deil, formaldehite ilave edilmelidir. Ayrca, reaksiyon karm iyice kartrlmal ve yaklak olarak fazla miktarda formaldehit kullanlmaldr. Arzu edilirse daha fazla miktarda formaldehit kullanlabilir; bununla birlikte, daha fazla formaldehit gerekli deildir.
Ayrca reaksiyon karmndaki piperazin konsantrasyonunun arlkça yaklak% 18’i atn kefettik. dier önlemlere uyulup uyulmadna baklmakszn bir polimer oluturulacaktr. Buna göre, piperazin arlkça yaklak% 18’den az olmaldr. toplam reaksiyon karmnn yüzdesi. Hem piperazin hem de formaldehit uygun bir çözücü içinde çözelti içinde olmaldr. Formaldehit, formaldehit için herhangi bir ilave çözücünün gerekli olmad bir formalin çözeltisi olarak kullanlabilir. Formaldehit ayrca formlarnn herhangi birinde kullanlabilir. lemin bu aamas için uygun çözücüler, hem piperazin hem de 1,4-piperazinedimetanolün çözünür olduu atl çözücülerdir. Metanol, etanol ve propanol gibi düük alifatik alkoller bu reaksiyon için mükemmel çözücülerdir. Dier uygun çözücüler arasnda örnein glikol monoand diyetleri, dioksan, düük tersiyer aminler ve su bulunur. Reaksiyon, yaklak 20 ila 25 ° C arasndaki ortam scaklklarnda kolayca ilerler veya istenirse daha yüksek scaklklar kullanlabilir. Üst scaklk limiti, kapal bir sistem kullanlmadkça ve reaksiyon basnç altnda yürütülmedikçe, çözücünün kaynama noktasdr. bir LCC yaklak 50 ° C’lk bir scakln özellikle avantajl olduu bulunmutur.
lemdeki ilk admdan elde edilen çözelti daha sonra dorudan hidrojenlenebilir, fakat tercihen hidrojenasyondan önce süzülür. Hidrojenasyon, bileenleri sv halde tutmak için yeterli bir basnçta, yaklak 50 ila yaklak 200 ° C arasndaki bir scaklkta gerçekletirilebilir. Böyle bir basnç yaklak 50 ila yaklak 3000 psig aralndadr. Hidrojenasyon aamasnn gerçekletirilmesinde, bir metalik hidrojenasyon katalizörü kullanlmaktadr. Uygun katalizörlerin örnekleri, bu dalda uzmanlam kimseler tarafndan iyi bilinmektedir. Bu tür katalizörler arasnda örnein platin, nikel ve bakr-krom oksit katalizörleri bulunur. Nikel bakr-krom katalizörlerinin özellikle etkili olduunu bulduk. Bu tip katalizörler yüzde 44 ila 94 atom nikel, yüzde 5 ila 55 atom bakr ve yüzde 1 ila 5 atom krom içerir. Tercih edilen spesifik bir katalizör, nikel oksit,% 22 kuprik oksit ve % 3 kromik oksitten oluan bir katalizördür.
lemin ilk admnn çeitli koullar altnda gerçekletirildii bir dizi çalmadan elde edilen sonuçlar Tablo I’de özetlenmitir. Bu çalmalarn amac polimer oluumunu incelemek ve ürünlerin birkaç ay bekletilmesine izin vermekti. Bu reaksiyonlarda formaldehit, formalin çözeltisi olarak kullanld ve piperazin için kullanlan çözücü metanoldü. Tipik bir çalmada, ilemin hidrojenasyon aamas aadaki ekilde gerçekletirildi. 1,4-piperazinedimetanol içeren birinci aamadaki reaksiyon karm süzüldü ve C scaklnda% 75 nikel oksit,% 22 kuprik oksit ve% 3 kromik oksit içeren bir nikel-bakr-kromya katalizörü kullanlarak hidrojenlendi ve yüzde 20 mol fazla hidrojen kullanlarak 2500 psig’lik bir basnç. Hidrojenlenmi ham ürün daha sonra saflatrlarak 1,4-dimetilpiperazin yüksek saflkta elde edildi. 1, 4-dimetilpiperazinin genel verimi, piperazin temelinde yüzde 88.7 mol idi.
Yukarda belirtildii gibi, 1,4-dimetilpiperazin ürünü hidrojenlenmi reaksiyon karmnda serbest halde bulunur ve uygun herhangi bir yolla karmdan ayrlabilir. Buluumuzu bu ekilde tarif ettikten sonra iddia edilen: 1. 1,4-dimetilpiperazin hazrlamak için aadakileri içeren bir yöntem:
(A) bir atl çözücü içinde bir piperazin çözeltisinin, bir atl çözücü içinde en az yaklak% 10 fazla formaldehit elde etmek üzere eklenmesi, böylece 1,4-piperazinedimetanol elde edilir, ad geçen piperazin arlkça yaklak% 18’den az oluturur. reaksiyon karmnn yüzdesi; ve (B) 1,4-piperazendimetano’yu 1,4’e hidrojenlemek yaklak 50 ila yaklak 200 ° C arasndaki bir scaklkta ve yaklak 50 ila yaklak 3000 psig’lik bir basnçta metalik bir hidrojenasyon katalizörü kullanan dimetilpiperazin,
2. stem 1 ‘deki gibi bir yöntem olup, eylemsiz çözücü metanol, etanol ve propanolden oluan gruptan seçilen düük bir alifatik alkoldür ve metalik hidrojenasyon katalizörü bir nikel-bakr-kromya katalizörüdür.
3. 1,4-dimetilpiperazin hazrlamak için aadakileri içeren bir yöntem:
(A) yaklak 20 ila yaklak 50 ° C arasndaki bir scaklkta en az yaklak% 10 fazla formalin çözeltisine metanolik bir piperazin çözeltisi eklenmesi, böylece 1,4-piperazinendimetanol elde edilmesi, söz konusu piperazin arlkça yaklak% 18’den az oluturur. reaksiyon karmnn yüzdesi; ve l (B) yaklak 50 ila yaklak 200 ° C arasndaki bir scaklkta ve yaklak 50 ila yaklak 3000 arasndaki bir basnçta bir nikel-bakr-5 kromi hidrojenasyon katalizörü kullanlarak 1,4-piperazinedimetanolün 1,4-dimetilpiperazine hidrojenletirilmesi psig,
Bis (N, N’-dimetilpiperazin) tetra [bakr (I) iyodür] , bakr (I) iyodür ve N, N’-dimetilpiperazinden oluan gözenekli ve fotolüminesan metal-organik bir çerçevedir (MOF) . American Elements, çou malzemeyi yüksek saflkta ve ultra yüksek saflkta (% 99.99999’a kadar) üretebilir ve geçerli ASTM test standartlarn takip eder; Mil Spec (askeri snf), ACS, Reaktif ve Teknik Snf, Gda, Tarm ve laç Snf, Optik Snf, USP ve EP / BP (Avrupa Farmakopesi / ngiliz Farmakopesi) dahil olmak üzere çeitli snflar mevcuttur. Özel kompozisyonlara ek olarak, talep üzerine özel artnamelere uygun malzemeler de üretebilirizticari ve aratrma uygulamalar ve yeni tescilli teknolojiler için.
Bu bulu dimetilpiperazin üretimi ile ilgilidir. Daha özel olarak, bu bulu piperazin, formaldehit ve hidrojenden 1,4-dimetilpiperazin üretimi ile ilgilidir.
imdiye kadar 1,4-dimetilpiperazin, piperazinin metilasyonu ile ‘Eschweiler [Ber. 38, 880 (1905)] veya bu prosedürün modifikasyonlar. Önceki teknik prosedürleri iki ciddi dezavantaja sahiptir. lk olarak, ar miktarda formaldehit ve formik asit kullanlr. Fazla formik asit kullanmnn bir sonucu olarak, arzu edilen ürün, reaksiyon karmnda format tuzu olarak bulunur ve saf ürünü elde etmek için ayrntl ayrma prosedürleri kullanlmaldr. kincisi, piperazin gibi bir poliaminin metilasyonunda, poliamin ve formaldehitin bir polimer oluturma eilimi vardr.
Önceki teknik ilemlerinin dezavantajlarnn üstesinden gelen 1,4-dimetilpiperazin üretimi için yeni bir ilem kefedilmitir. Bu ilem, uygun bir çözücü içinde bir piperazin çözeltisinin biraz fazla formaldehite ilave edildii ve piperazinedimetanol içeren bu reaksiyon karmnn, daha sonra istenen 1,4- dimetilpiperazin. Bu ilem kullanlarak mükemmel verim elde edilmitir. Reaksiyon sisteminde formik asit veya baka bir asit bulunmadndan, 1,4-dimetilpiperazin ürün karmnda serbest halde bulunur. Dimetilpiperazin böylece reaksiyon karmndan, örnein damtma gibi herhangi bir uygun yolla ayrlabilir.
Piperazin ve formaldehit arasndaki reaksiyon srasnda bir polimer oluumundan kaçnmak için, piperazin, tersine deil, formaldehite ilave edilmelidir. Ayrca, reaksiyon karm iyice kartrlmal ve yaklak olarak fazla miktarda formaldehit kullanlmaldr. Arzu edilirse daha fazla miktarda formaldehit kullanlabilir; bununla birlikte, daha fazla formaldehit gerekli deildir. Ayrca reaksiyon karmndaki piperazin konsantrasyonunun arlkça yaklak% 18’i atn kefettik. dier önlemlere uyulup uyulmadna baklmakszn bir polimer oluturulacaktr.
Tipik bir çalmada, ilemin hidrojenasyon aamas aadaki ekilde gerçekletirildi. 1,4-piperazinedimetanol içeren birinci aamadaki reaksiyon karm süzüldü ve C scaklnda% 75 nikel oksit,% 22 kuprik oksit ve% 3 kromik oksit içeren bir nikel-bakr-kromya katalizörü kullanlarak hidrojenlendi ve yüzde 20 mol fazla hidrojen kullanlarak 2500 psig’lik bir basnç. Hidrojenlenmi ham ürün daha sonra saflatrlarak 1,4-dimetilpiperazin yüksek saflkta elde edildi. 1, 4-dimetilpiperazinin genel verimi, piperazin temelinde yüzde 88.7 mol idi.
Yukarda belirtildii gibi, 1,4-dimetilpiperazin ürünü hidrojenlenmi reaksiyon karmnda serbest halde bulunur ve uygun herhangi bir yolla karmdan ayrlabilir.
Buluumuzu bu ekilde tarif ettikten sonra iddia edilen:
1. 1,4-dimetilpiperazin hazrlamak için aadakileri içeren bir yöntem: (A) bir atl çözücü içinde bir piperazin çözeltisinin, bir atl çözücü içinde en az yaklak% 10 fazla formaldehit elde etmek üzere eklenmesi, böylece 1,4-piperazinedimetanol elde edilir, ad geçen piperazin arlkça yaklak% 18’den az oluturur. reaksiyon karmnn yüzdesi; ve (B) 1,4-piperazendimetano’yu 1,4’e hidrojenlemek yaklak 50 ila yaklak 200 ° C arasndaki bir scaklkta ve yaklak 50 ila yaklak 3000 psig’lik bir basnçta metalik bir hidrojenasyon katalizörü kullanan dimetilpiperazin
2. stem 1 ‘deki gibi bir yöntem olup, eylemsiz çözücü metanol, etanol ve propanolden oluan gruptan seçilen düük bir alifatik alkoldür ve metalik hidrojenasyon katalizörü bir nikel-bakr-kromya katalizörüdür.
3. 1,4-dimetilpiperazin hazrlamak için aadakileri içeren bir yöntem: (A) yaklak 20 ila yaklak 50 ° C arasndaki bir scaklkta en az yaklak% 10 fazla formalin çözeltisine metanolik bir piperazin çözeltisi eklenmesi, böylece 1,4-piperazinendimetanol elde edilmesi, söz konusu piperazin arlkça yaklak% 18’den az oluturur. reaksiyon karmnn yüzdesi; ve l (B) yaklak 50 ila yaklak 200 ° C arasndaki bir scaklkta ve yaklak 50 ila yaklak 3000 arasndaki bir basnçta bir nikel-bakr-5 kromi hidrojenasyon katalizörü kullanlarak 1,4-piperazinedimetanolün 1,4-dimetilpiperazine hidrojenletirilmesi psig.
Tek bir iridyum katalizörü kullanan azot heterosiklik bileiklerin hidrojenasyonuna ve dehidrojenasyonuna dayanan yeni bir hidrojen depolama sistemi gelitirilmitir. Bu yeni sistem, önceki sistemlere kyasla nispeten az miktarda çözücü kullanlarak verimli hidrojen depolamas saland. 2,5 ‐ dimetilpirazin ve 2,5 ‐ dimetilpiperazin arasndaki geri dönüümlü dönüümler, üç edeer hidrojenin alnmas ve serbest braklmas ile birlikte, herhangi bir verimlilik kayb olmakszn neredeyse nicel olarak en az dört kez tekrarlanabilir. Ayrca çözücü içermeyen koullar altnda hidrojen depolama da gerçekletirildi.