1-Methylimidazole is an aromatic heterocyclic organic compound with the formula CH3C3H3N2. It is a colourless liquid that is used as a specialty solvent, a base, and as a precursor to some ionic liquids. It is fundamental nitrogen heterocycle and as such mimics for various nucleoside bases as well as histidine and histamine. The CAS NO of 1-Methylimidazole is 616-47-7. With the N-methyl group, this particular derivative of imidazole cannot tautomerize. It is slightly more basic than imidazole, as indicated by the pKa's of the conjugate acids of 7.0 and 7.4. Methylation also provides a significantly lower melting point, which makes 1-methylimidazole a useful solvent.
meta -Xylenediamine (MXDA) is useful as chemical inter-mediates in the plastic and polymer fields. This compound can be prepared from the hydrogenation of isophthalonitrile(IPN) in the presence of ammonia using nickel catalyst or other metallic catalysts under high temperature and pressure.
However optimum reaction conditions are crucial to produce a high grade of MXDA because of the formation of undesirable products resulting from a partial hydrogenation, a polymerization or cleavage of the product.
In order to prevent the side reactions, IPN were hydrogenated in the presence of ammonia with organic solvents. Especially the correct choice of a solvent is a critical factor to govern the catalytic activity with desirable hydrogenation.
Conven-tionally, organic materials such as aromatic hydrocarbons,aliphatic alcohols, aliphatic hydrocarbons, dimethylform-amide and dioxane were employed in this reaction. Several MXDA producing processes with the organic solvent including m-xylene, pseudocumene, mesitylene, ethylben-zene, methylpyridine(CAS NO:616-47-7), benzonitrile, m-tolunitrile, MXDA and cyanopyridine were disclosed.
However, the solvents and ammonia were vaporized under the operation conditions leading to amine cleavage with the resulting formation of methylbenzyl amines or the consumption of ammonia was still significant. Recently, some researchers reported that a high yield of MXDA was achieved using isopropanol under relatively low pressure condition; however, the consumption of ammonia was very significant.
We used 1-methylimidazole for the hydrogenation of IPN to produce MXDA. Imidazole is a heterocyclic compound of five-membered diunsaturated ring structure composed of three carbon atoms and two nitrogen atoms at nonadjacent positions. Imidazoles are barely soluble in water normally, but are dissolved in organic solvents.
Here we report the successful preparation of MXDA by hydrogenation of IPN in the presence of low ammonia concentration using 1-methylimidazole as an effective solvent.
In conclusion, 1-methylimidazole was shown to outper- form the other organic solvents in this reaction. Moreover, amount of ammonia with using 1-methylimidazole as a solvent was lower than other processes. Thus, 1-methylimidazole is an attractive solvent in IPN hydrogenation for
the production of MXDA.
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2013年12月1日星期日
2013年11月10日星期日
Summary of 1-Methylimidazole
Product Name: 1-Methylimidazole
Molecular Formula: C4H6N2
Molecular Weight: 82.1
EINECS: 210-484-7
CAS Data Base Reference: 616-47-7
Chemical Properties: 1-Methylimidazole is clear colorless to yellow liquid.
Usage: A metabolite of 1-methyl-2-thioimidazole. It inhibits bone resorption.
Stability: Stable, but moisture sensitive. Incompatible with acids, acid anhydrides, strong oxidizing agents, moisture, carbon dioxide, acid chlorides.
1-Methylimidazole(CAS NO:616-47-7) is an aromatic heterocyclic organic compound with the formula CH3C3H3N2. It is a colourless liquid that is used as a specialty solvent, a base, and as a precursor to some ionic liquids. It is fundamental nitrogen heterocycle and as such mimics for various nucleoside bases as well as histidine and histamine.
With the N-methyl group, this particular derivative of imidazole cannot tautomerize. It is slightly more basic than imidazole, as indicated by the pKa's of the conjugate acids of 7.0 and 7.4. Methylation also provides a significantly lower melting point, which makes 1-methylimidazole a useful solvent.
1-Methylimidazole is prepared mainly by two routes industrially. The main one is acid-catalysed methylation of imidazole by methanol. The second method involves the Radziszewski reaction from glyoxal, formaldehyde, and a mixture of ammonia and methylamine.
(CHO)2 + CH2O + CH3NH2 + NH3 → H2C2N(NCH3)CH + 3 H2O
The compound can be synthesized on a laboratory scale by methylation of imidazole at the pyridine-like nitrogen and subsequent deprotonation. Similarly, 1-methylimidazole may be synthesized by first deprotonating imidazole to form a sodium salt followed by methylation.
H2C2N(NH)CH + CH3I → [H2C2(NH)(NCH3)CH]I
H2C2(NH)(NCH3)CH + NaOH → H2C2N(NCH3)CH + H2O + NaI
In the research laboratory, 1-methylimidazole and related derivatives have been used as mimic aspects of diverse imidazole-based biomolecules. It is also the precursor for the synthesis of the methylimidazole monomer of pyrrole-imidazole polyamides. These polymers can selectively bind specific sequences of double-stranded DNA by intercalating in a sequence dependent manner.
BASF has used 1-methylimidazole as a means to remove acid during their industrial-scale production of diethoxyphenylphosphine. In this biphasic acid scavenging using ionic liquids (BASIL) process, 1-methylimidazole reacts with HCl to produce 1-methylimidazolium chloride, a salt that is easily separated and deprotonated to regenerate 1-methylimidazole.
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Molecular Formula: C4H6N2
Molecular Weight: 82.1
EINECS: 210-484-7
CAS Data Base Reference: 616-47-7
Chemical Properties: 1-Methylimidazole is clear colorless to yellow liquid.
Usage: A metabolite of 1-methyl-2-thioimidazole. It inhibits bone resorption.
Stability: Stable, but moisture sensitive. Incompatible with acids, acid anhydrides, strong oxidizing agents, moisture, carbon dioxide, acid chlorides.
1-Methylimidazole(CAS NO:616-47-7) is an aromatic heterocyclic organic compound with the formula CH3C3H3N2. It is a colourless liquid that is used as a specialty solvent, a base, and as a precursor to some ionic liquids. It is fundamental nitrogen heterocycle and as such mimics for various nucleoside bases as well as histidine and histamine.
With the N-methyl group, this particular derivative of imidazole cannot tautomerize. It is slightly more basic than imidazole, as indicated by the pKa's of the conjugate acids of 7.0 and 7.4. Methylation also provides a significantly lower melting point, which makes 1-methylimidazole a useful solvent.
1-Methylimidazole is prepared mainly by two routes industrially. The main one is acid-catalysed methylation of imidazole by methanol. The second method involves the Radziszewski reaction from glyoxal, formaldehyde, and a mixture of ammonia and methylamine.
(CHO)2 + CH2O + CH3NH2 + NH3 → H2C2N(NCH3)CH + 3 H2O
The compound can be synthesized on a laboratory scale by methylation of imidazole at the pyridine-like nitrogen and subsequent deprotonation. Similarly, 1-methylimidazole may be synthesized by first deprotonating imidazole to form a sodium salt followed by methylation.
H2C2N(NH)CH + CH3I → [H2C2(NH)(NCH3)CH]I
H2C2(NH)(NCH3)CH + NaOH → H2C2N(NCH3)CH + H2O + NaI
In the research laboratory, 1-methylimidazole and related derivatives have been used as mimic aspects of diverse imidazole-based biomolecules. It is also the precursor for the synthesis of the methylimidazole monomer of pyrrole-imidazole polyamides. These polymers can selectively bind specific sequences of double-stranded DNA by intercalating in a sequence dependent manner.
BASF has used 1-methylimidazole as a means to remove acid during their industrial-scale production of diethoxyphenylphosphine. In this biphasic acid scavenging using ionic liquids (BASIL) process, 1-methylimidazole reacts with HCl to produce 1-methylimidazolium chloride, a salt that is easily separated and deprotonated to regenerate 1-methylimidazole.
Want to learn more information about 1-methylimidazole, you can access the guidechem.com. Guidechem.com is just a place for you to look for some chemicals. Guidechem provide the most convenient conditions for the international buyers and let these leads benefit all the business people. Guidechem chemical B2B network provides information on china and global chemical market quotation and relative chemical Information. Guidechem Chemical Network providing the most complete information of the chemical industry.
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