1-метил-2-пирролидинон

Описание

N-Methyl-2-pyrrolidone is an aprotic solvent with a wide range of applications: petrochemical processing, surface coating, dyes and pigments, industrial and domestic cleaning compounds, and agricultural and pharmaceutical formulations. It is mainly an irritant, but has also caused several cases of contact dermatitis in a small electrotechnical company.

Химические свойства

N-Methyl-2-pyrrolidone is a colourless or light yellow liquid with an amine odour. It can undergo a number of chemical reactions even though it is accepted as a stable solvent. It is resistant to hydrolysis under neutral conditions, but strong acid or base treatment results in ring opening to 4-methyl aminobutyric acid. N-Methyl-2-pyrrolidone can be reduced to 1-methyl pyrrolidine with borohydride. Treatment with chlorinating agents results in amide formation,an intermediate which can undergo further substitution, while treatment with amyl nitrate yields the nitrate. Olefins can be added to the 3 position by treatment first with oxalic esters, then with appropriate aldehyes (Hort and Anderson 1982).

Использование

N-Methyl-2-pyrrolidone is a polar solvent that is used in organic chemistry and polymer chemistry. Large scale applications include the recovery and purification of acetylenes, olefins, and diolefins, gas purification, and aromatics extraction from feedstocks.N-Methyl-2-pyrrolidone is a versatile industrial solvent. NMP is currently approved for use only in veterinary pharmaceuticals. The determination of the disposition and metabolism of NMP in the rat will contribute toward understanding the toxicology of this exogenous chemical which man may likely be exposed to in increasing amounts.

Методы производства

N-Methyl-2-pyrrolidone is manufactured by the reaction of buytrolactone with methylamine (Hawley 1977). Other processes include preparation by hydrogenation of solutions of maleic or succinic acids with methylamine (Hort and Anderson 1982). Manufacturers of this chemical include Lachat Chemical, Inc, Mequon, Wisconsin and GAF Corporation, Covert City, California.

Определение

ChEBI: N-methylpyrrolidin-2-one is a member of the class of pyrrolidine-2-ones that is pyrrolidin-2-one in which the hydrogen attached to the nitrogen is replaced by a methyl group. It has a role as a polar aprotic solvent. It is a N-alkylpyrrolidine, a lactam and a member of pyrrolidin-2-ones.

Общее описание

N-Methyl-2-Pyrrolidone (NMP) is a powerful, aprotic solvent with high solvency, and low volatility. This colorless, high boiling, high flash point and low vapor pressure liquid carries a mild amine-like odor. NMP has high chemical and thermal stability and is completely miscible with water at all temperatures. NMP can serve as a co-solvent with water, alcohols, glycol ethers, ketones, and aromatic/chlorinated hydrocarbons. NMP is both recyclable by distillation and readily biodegradable. NMP is not found on the Hazardous Air Pollutants (HAPs) list of the 1990 Clean Air Act Amendments.

Реакции воздуха и воды

Soluble in water.

Профиль реактивности

This amine is a very mild chemical base. N-Methyl-2-pyrrolidone does tend to neutralize acids to form salts plus water. The amount of heat that is evolved per mole of amine in a neutralization is largely independent of the strength of the amine as a base. Amines may be incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. Flammable gaseous hydrogen is generated by amines in combination with strong reducing agents, such as hydrides.

Опасность

Severe skin and eye irritant. Explosive lim-its 2.2–12.2%.

Угроза здоровью

Inhalation of hot vapors can irritate nose and throat. Ingestion causes irritation of mouth and stomach. Contact with eyes causes irritation. Repeated and prolonged skin contact produces a mild, transient irritation.

Пожароопасность

Special Hazards of Combustion Products: Toxic oxides of nitrogen may be formed in fire.

Промышленное использование

1) N-Methyl-2-pyrrolidone is used as a general dipolar aprotic solvent, stable and unreactive;
2) for extraction of aromatic hydrocarbons from lubricating oils;
3) for carbon dioxide removal in ammonia generators;
4) as a solvent for polymerization reactions and polymers;
5) as a paint stripper;
6) for pesticide formulations (USEPA 1985).
Other non-industrial uses of N-Methyl-2-pyrrolidone are based on its properties as a dissociating solvent suitable for electrochemical and physical chemical studies (Langan and Salman 1987). Pharmaceutical applications make use of the properties of N-Methyl-2-pyrrolidone as a penetration enhancer for a more rapid transfer of substances through the skin (Kydoniieus 1987; Barry and Bennett 1987; Akhter and Barry 1987). N-Methyl-2-pyrrolidone has been approved as a solvent for slimicide application to food packaging materials (USDA 1986).

Контактные аллергены

N-Methyl-2-pyrrolidone is an aprotic solvent with a wide range of applications: petrochemical processing, surface coating, dyes and pigments, industrial and domestic cleaning compounds, and agricultural and pharmaceutical formulations. It is mainly an irritant, but it can cause severe contact dermatitis due to prolonged contact.

Профиль безопасности

Poison by intravenous route. Moderately toxic by ingestion and intraperitoneal routes. Mildly toxic by skin contact. An experimental teratogen. Experimental reproductive effects. Mutation data reported. Combustible when exposed to heat, open flame, or powerful oxidizers. To fight fire, use foam, CO2, dry chemical. When heated to decomposition it emits toxic fumes of NOx.

Описание

1-метил-2-пирролидинон(NMP),это полярное апротонное соединение с низкой вязкостью и высокой стабильностью. Он только медленно окисляется воздухом и легко очищается фракционной дистилляцией. NMP гигроскопичен. Вещество целиком растворяется в воде. Он сильно растворим в низших спиртах, низших кетонах, простом эфире, этилацетате, хлороформе и бензоле и умеренно растворим в алифатических углеводородах.

Химические свойства

1-метил-2-пирролидинон,Бесцветная или светло-желтая жидкость с запахом амина.Стабильный, но разлагается при воздействии света. Горюче. Несовместим с сильными окислителями, сильными кислотами, восстановителями, основаниями.

Канцерогенность

Rats were exposed to N-Methyl-2-pyrrolidone vapor at 0, 0.04, or 0.4 mg/L for 6 h/day, 5 days/week for 2 years.Male rats at 0.4 mg/L showed slightly reduced mean body weight. No life-shortening toxic or carcinogenic effects were observed in rats exposed for 2 years to either 0.04 or 0.4mg/L of N-Methyl-2-pyrrolidone. By the dermal route, a group of 32 mice received an initiation dose of 25mg of N-Methyl-2-pyrrolidone followed 2 weeks later by applications of the tumor promoter phorbol myristate acetate, three times a week, for more than 25 weeks. Dimethylcarbamoyl chloride and dimethylbenzanthracene served as positive controls. Although the N-Methyl-2-pyrrolidone group had three skin tumors, this response was not considered significant when compared with that of the positive controls.

Применение

1-метил-2-пирролидинон–сильный растворитель с невысокой летучестью, поэтому находит широкое применение, например N-метилпирролидон используют в качестве полярного растворителя в органической и полимерной химии.

Производство

N-метил-2-пирролидон преимущественно осуществляют путем взаимодействия гамма-бутиролактона с избытком чистого или водного метиламина в трубчатом реакторе высокого давления (6-12 МПа).

Метаболический путь

Rats are administered radio-labeled N-methyl-2- pyrrolidinone (NMP), and the major route of excretion by rats is via the urine. The major metabolite, representing 70-75% of the administered dose, is 4-(methylamino)butenoic acid. This unsaturated intact product may be formed from the elimination of water, and a hydroxyl group may be present on the metabolite prior to acid hydrolysis.

Метаболизм

Male Sprague-Dawley rats were given a single intraperitoneal injection (45 mg/kg) of radiolabeled 1-methyl-2-pyrrolidone. Plasma levels of radioactivity and compound were monitored for six hours and the results suggested a rapid distribution phase which was followed by a slow elimination phase. The major amount of label was excreted in the urine within 12 hours and accounted for approximately 75% of the labelled dose. Twenty-four hours after dosage, cumulative excretion (urine) was approximately 80% of the dose. Both ring- and methyl-labeled species were used, as well as both [¹⁴C]- and [3H]-labeled l-methyl-2-pyrrolidone. The initial labeled ratios were maintained during the first 6 hours after dosage. After 6 hours, the liver and intestines were found to contain the highest accumulations of radioactivity, approximately 2-4% of the dose. Little radioactivity was noted in the bile or respired air. High performance liquid chromatography of urine showed the presence of one major and two minor metabolites. The major metabolite (70-75% of the administered radioactive dose) was analyzed by liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry and was proposed to be a 3- or 5-hydroxy-l-methyl-2-pyrrolidone (Wells 1987).

Методы очистки

Dry the pyrrolidone by removing water as the *benzene azeotrope. Fractionally distil at 10 torr through a 100-cm column packed with glass helices. [Adelman J Org Chem 29 1837 1964, McElvain & Vozza J Am Chem Soc 71 896 1949.] The hydrochloride has m 86-88o (from EtOH or Me2CO/EtOH) [Reppe et al. Justus Liebigs Ann Chem 596 1 1955]. [Beilstein 21 II 213, 21 III/IV 3145, 21/6 V 321.]