RU2282611C1 - Method for production of alkane, cycloalkane and arylalkane monobromoderivatives - Google Patents

Abstract

FIELD: organic chemistry.

SUBSTANCE: claimed method includes reaction between corresponding hydrocarbons with tetra bromomethane at 150-180°C in liquid phase in presence of copper chloride or copper bromide complex with nitrogen-containing substance, wherein as nitrogen-containing substance amine of general formula Ph-CH(OH)-Q-NHR' is used. In formula: Q is group -CH(CH₃)- or -(CH₂)_n, wherein n = 1-3; R' is lower alkyl.

EFFECT: increased catalyst productivity, simplified process of decreased cost.

12 ex, 1 tbl

Description

The invention relates to the chemical industry and fine organic synthesis, in particular to the production of monobromo derivatives of alkanes, cycloalkanes and arylalkanes.

Monobromo derivatives of alkanes, cycloalkanes and arylalkanes are widely used in the manufacture of pharmaceuticals, surfactants and in other areas of industrial fine organic synthesis.

Obtaining monobromo derivatives of hydrocarbons is a difficult task. Direct bromination of alkanes and their analogues with molecular bromine is reversible and non-selective; at present, this method of producing organic bromine derivatives is practically not used [F.F. Muganlinsky, Yu.A. Treger, M. M. Lyushin, Chemistry and technology of organohalogen compounds, M. Chemistry, 1991, p.227].

There is a method of producing monobromoalkanes by reacting the corresponding alcohols with molecular bromine in a solution of benzene or toluene in the presence of sulfur and iron bromide [USSR Copyright Certificate 468906, MKI C 07 C 19/02, 1975]. In other methods, it is proposed to use chromium (VI) oxide as catalysts [USSR author's certificate 392682, MKI C 07 C 19/02, 1975], MnO ₂ [USSR author's certificate 406448, MKI C 07 C 19/02, 1974] and so on. .d. The disadvantage of these methods is the use of toxic molecular bromine and catalysts, the separation of which with the reaction products is an independent complex task, as well as the low availability of higher aliphatic alcohols in the preparation of the corresponding bromine derivatives.

Of considerable interest would be the possibility of obtaining bromine derivatives from the corresponding hydrocarbons by reaction with polybromine derivatives, for which effective single-stage production methods have been developed to date - for example, CBr _{4 is} easily and with high selectivity obtained by the interaction of sodium bromide with acetone. A known method for producing monobromo derivatives of alkanes and cycloalkanes by reacting the latter with CBr ₄ in a two-phase system in the presence of sodium hydroxide [PRSchreiner, O. Lauenstein, Angew. Chem. Int. Ed., 1998, v. 37, p. 1895]. The disadvantage of this method is low productivity - the reaction time reaches 90 hours, and the product yield is in the range of 30-70%. There is also a method for producing monobromoalkanes by reacting the corresponding alkanes with the complex CBr ₄ .2AlBr ₃ [I.S.Akhrem, A.V. Orlinkov, L.V. Afanasyeva, M.E. Volpin, Izvestiya AN SSSR, ser. Chem., 1996, p.1208]. A twofold excess of aluminum bromide and the sensitivity of the brominating agent to moisture complicate the practical implementation of the method.

The closest analogue to the described method in essence and the technical result achieved is a method for producing monobromo derivatives of alkanes, cycloalkanes and arylalkanes by reacting the corresponding hydrocarbons with CBr ₄ at a temperature of 150-180 ° C in the presence of CuBr complexes of CuBr ₂ with quaternary ammonium bromides or grafted onto silica by polymetallophenylsiloxanes containing copper or nickel as a metal [V.V. Smirnov, V.M. Zelikman, I.P. Beletskaya et al. Zhurn. organ. Chemistry, 2003, vol. 38, No. 1, p. 1004]. The method provides a high yield of target products. The disadvantage of this method is the low productivity of the catalyst (not more than 0.6 g of product / g of catalyst per hour), which leads to a large consumption of deficient catalyst components. In addition, the use of a catalyst in an amount of up to 10 wt.% Of the reaction mass complicates the isolation of the target product.

The objective of the invention is to provide a method for producing monobromo derivatives of alkanes, cycloalkanes and arylalkanes by reacting the corresponding hydrocarbons with CBr ₄ at a temperature of 150-180 ° C, which provides increased catalyst productivity and, therefore, simplification and cheapening of the process technology.

The problem is solved by the method of producing monobromo derivatives of alkanes, cycloalkanes and arylalkanes by reacting the corresponding hydrocarbons with tetrabromomethane at a temperature of 150-180 ° C in the liquid phase in the presence of a complex of copper chloride with a nitrogen-containing compound of the formula

Ph-CH (OH) -Q-NHR ',

where Q is the group —CH (CH ₃ ) - or - (CH ₂ ) _n - at n = 2-3, R ′ is lower alkyl.

The technical result obtained using the above invention consists in a significant (7-10 times) increase in the productivity of the catalyst, which allows it to be used in much smaller quantities, thereby simplifying and cheapening the process technology.

The invention is illustrated by the following examples.

Example 1

Preparation of Catalyst I. 1 g (0.01 mol) of copper (I) chloride and 100 ml (2 mol) of acetonitrile are placed in a glass flask. After the salt has completely dissolved, 1.6 g (0.01 mol) of 3- (N-methylamino) -1-phenylpropanol-1 (AM) is added. After a few minutes, the precipitate was filtered off and dried in air. The mass of the obtained catalyst of the general formula (CuCl) _2. (AM) ₂ is 2.5 g. The mother liquor is distilled, separating the pure solvent. Regenerated acetonitrile is used for subsequent experiments.

The catalysts were prepared in a similar manner:

II (CuBr) ₂ (AM) ₂ - the same amine

III (CuCl) ₂ (AM ') ₂ AM'Q = (CH ₂ ) ₃

IV (CuCl) ₂ (AM`` ') ₂ AM''Q = CH (CH ₃ ) -

V (CuCl) ₂ (AM`` ') ₂ AM'Q = (CH ₂ ) ₂ R' = nC ₃ H ₇

Example 2. The synthesis.

10 ml (0.05 mol) of n-decane, 3.3 g (0.01 mol) of tetrabromomethane and 40 mg of catalyst are placed in a thick-walled glass reaction vessel. The vessel is placed in a special apparatus, providing mixing of the reaction mass due to uneven rotation, heated to 160 ° C and held for 3 hours. 1.4 g (70% of theory) of monobromododecane are isolated. The productivity of the catalyst is 11.7 g of product per 1 g of catalyst per hour.

The use of a catalyst in amounts of more or less selected is impractical: a decrease leads to a significant decrease in the conversion of reagents, and an increase does not give a measurable positive effect and only increases the consumption of catalyst. Similarly lead the process in examples 3-12.

The conditions and results of the experiments are collected in the table.

Table
Conditions and results of experiments to obtain monobromo derivatives of hydrocarbons No. p / p catalyst hydrocarbon reaction time, hour Temperature ° C Exit, % Productivity g / g.h 2 I n-dean 3 160 70 11.7 3 II n-dean 3 160 75 12.0 four III n-dean 3 160 78 12.3 5 IV n-dean 3 160 75 12.0 6 I dodecan 5 160 80 * 12.5 7 IV n-dean 5 150 70 11.7 8 IV n-dean 5 140 45 7.8 9 IV n-dean 3 180 83 ** 12.8 10 I cyclohexane 3 190 80 ** 12.5 eleven I m-xylene four 160 80 12.5 12 II *** n-dean 3 160 82 12.7 * - keeping the reaction mass for 5 hours without additional loading of the catalyst leads to a slight increase in the yield of monobromodecane, while up to 5% of heavy osmol products are found in the mixture. ** - 5-6% of heavy osmol products were found in the mixture. *** - in the experiment used 75 mg of catalyst

Claims (1)

A method of producing monobromo derivatives of alkanes, cycloalkanes and arylalkanes by reacting the corresponding hydrocarbons with tetrabromomethane at a temperature of 150-180 ° C in the liquid phase in the presence of a complex of copper chloride or bromide with a nitrogen-containing compound, characterized in that an amine of the general formula is used as a nitrogen-containing compound Ph-CH (OH) -Q-NHR ', where Q is the group —CH (CH ₃ ) - or - (CH ₂ ) _n - at n = 1-3, R 'is lower alkyl.