DE1083261B - Process for the preparation of tertiary alkylcyclopentadienes - Google Patents

Description

Process for the preparation of tertiary alkylcyclopentadienes Die The present invention relates to the production of tertiary alkylcyclopentadienes, those as intermediates in the manufacture of dicyclopentadienyl iron derivatives Are of value as hematopoietic agents in the treatment of anemia in humans and Animals find use.

From Liebig's Annalen der Chemie, Vol. 524, 1936, p. 145, the production of normal and secondary alkyl derivatives of cyclopentadiene, such as methyl, Ethyl, isopropyl or n-butyl derivatives or mono- or dibenzyl derivatives Reaction of cyclopentadienyl potassium with the corresponding alkyl or benzyl halide known by refluxing for several hours in the presence of benzene. Until now However, no attempts are described in the literature, according to which cyclopentadienyl potassium reacts with a tertiary alkyl halide. The expert had to work out of this fact infer that tertiary alkyl halides with cyclopentadienyl potassium compounds at all could not be implemented.

There is also no known literature in which the implementation of Cyclopentadienyl magnesium halides, cyclopentadienyl zinc halides, dicyclopentadienyte magnesium or dicyclopentadienyl manganese with a straight or branched chain Alkyl halide is described. So the expert could not have expected that the inventive reaction between a cyclopentadienyl magnesium halide, Cyclopentadienyl zinc halide, dicyclopentadienyl magnesium and dicyclopentadienyhnangane, respectively and a tertiary alkyl halide can be carried out with satisfactory yields would.

The technology thus becomes unpredictable through the inventive concept Wise running procedures enriched considerably.

According to the present invention, tertiary alkylcyclopentadienes are prepared which have the following formula: where R ', R "and R"' denote alkyl radicals.

A preferred group of compounds according to the above formula is that in which R ', R "and R"' represent alkyl radicals containing up to 8 carbon atoms contain; in addition, a group of compounds according to this formula is preferred produced in which the radicals R ', R "and R"' together do not have more than 8 carbon atoms contain.

There are in particular tertiary butylcyclopentadiene, tertiary amylcyclopentadiene and (1-methyl-1-ethylpropyl) -cyclopentadiene produced.

According to the invention are a cyclopentadienyl magnesium halide or a cyclopentadienyl zinc halide and a tertiary alkyl halide, e.g. B. tertiary Butyl chloride, tertiary amyl chloride or 3-chloro-3-methylpentane, reacted.

A suitable cyclopentadienyl magnesium halide can e.g. B. Cydopentadienyl magnesine bromide be. The process can also be carried out in the presence of an inert diluent or solvent be carried out, e.g. B. diethyl ether or di-n-butyl ether.

The cyclopentadienyl magnesium halides used as starting material can be obtained by known methods, e.g. B. by implementing Cyclopentadiene and an alkyl magnesium halide such as methyl magnesium iodide or Ethyl magnesium bromide.

As cyclopentadienyl zinc halide, for. B. Cyclopentadienyl zinc chloride be suitable, and the process can be in the presence of one or more inert Diluents or solvents are carried out, e.g. B. diethyl ether or tetrahydrofuran.

The zinc halides used as starting materials can be known manner, e.g. B. by reacting cyclopentadienyl sodium with the corresponding zinc halide.

The new compounds can also be obtained by reacting dicyclopentadienyl magnesium or manganese with a tertiary alkyl halide, e.g. B. tertiary butyl chloride, tertiary Amyl chloride or 3-chloro-3-methylpentane.

This process can also be used in the presence of an inert diluent. or solvent, e.g. B. tetrahydrofuran.

The dicyclopentadienyl magnesium used as the starting material or Manganese can be obtained by mixing cyclopentadienyl sodium with the corresponding Metal halide, such as magnesium chloride or Man.ganbromid, is implemented.

The invention is illustrated by the following examples in which the parts relate to weight.

Example 1 A solution of 546 parts of ethyl bromide in 800 parts of diethyl ether becomes a stirred suspension of 120 parts of magnesium turnings and 80 parts Diethyl ether given within 2 hours. The mix then becomes yet another Hour stirred. 264 parts of cyclopentadiene are then added over the course of 1 hour added to the mixture and, after stirring for a further 24 hours, 556 parts of tertiary Butyl chloride added within 90 minutes. The reaction mixture is 24 hours stirred and then poured onto 5000 parts of crushed ice. The ethereal layer is separated and washed with water and dried over anhydrous sodium sulfate. The ether is removed under reduced pressure. The residue gives after the distillation tertiary butylcyclopentadiene, Kr. 28 45 "C, yield 660 / o.

Example 2 70 parts of cyclopentadiene are added over the course of 1 hour to a suspension of 23 parts of finely divided sodium in 200 parts of tetrahydrofuran given in a nitrogen atmosphere and at a temperature of 25 to 300 C. The mixture is stirred for a further 2 hours. 100 parts of anhydrous manganese dibromide are added over 30 minutes and the mixture is stirred for 90 minutes. The mixture is then cooled to 25 ° C and 92 parts of tertiary butyl chloride are added within 30 minutes. The mixture is then heated to 50 ° C and stirred at this temperature for a further 90 minutes. It is then cooled to 25 "C, and 100 parts of petroleum ether (boiling point 40 to 600 ° C.) are added. The mix will poured into water and the petroleum ether layer separated, washed with water and dried over anhydrous sodium sulfate. The petroleum ether is reduced at The pressure was removed and the residue was fractionally distilled under reduced pressure. Thus tertiary butyl-cyclopentadiene is obtained, boiling point 28 45 "C, yield 901.

Example 3 The procedure described in Example 2 is repeated, however, instead of 100 parts of anhydrous manganese bromide, 40 parts becomes anhydrous Magnesium chloride used. Tertiary butylcyclopentadiene is used in a corresponding manner obtained, b.p. 28,450C, yield 3ovo.

Example 4 The procedure described in Example 1 is repeated, however, instead of 556 parts of tertiary butyl chloride, 640 parts become tertiary Amyl chloride used.

Tertiary amylcyclopentadiene is thus obtained, boiling point 551 "C, yield 67ozon Example 5 The procedure described in Example 1 is repeated, however instead of 556 parts of tertiary butyl chloride, 895 parts of 2-chloro-2,4,4-trimethylpentane are used ver applies: This gives (1,1,3,3-tetramethylbutyl) -cyclopentadiene, Kr ,,, 350 C, yield 3501.

Example 6 The procedure described in Example 1 is repeated, however, instead of 556 parts of tertiary butyl chloride, 725 parts of 3-chloro-3-methylpentane are used used. This gives (l-methyl-l-ethylpropyl) cyclopentadiene, boiling point 4 389C, Yield 66%.

Example 7 The procedure described in Example 1 is repeated, however, instead of 556 parts of tertiary butyl chloride, 725 parts of 2-chloro-2-methylpentane are used used. This gives (1,1-dimethylbutyl) cyclopentadiene, boiling point 5.25 ° C. Yield 6801.

Example 8 70 parts of cyclopentadiene are added over the course of 1 hour to a suspension of 23 parts finely distributed in 200 parts of tetrahydrofuran Sodium in a nitrogen atmosphere and at a temperature of 25 to 300 ° C admitted. The mixture is stirred for a further 2 hours and then over the course of 1 Hour to a stirred suspension of 136 parts of powdered, anhydrous zinc chloride given in 300 parts of ether at 25 to 300 C. The mixture is then stirred for 3 hours. 92.5 parts of tertiary butyl chloride are within 30 minutes at 25 to 300 C is added and the mixture is stirred for a further 90 minutes. Then the mixture poured in water and. separated the ethereal layer, washed with water and dried over anhydrous sodium sulfate. The ether is diminished The pressure was removed and the residue was fractionally distilled under reduced pressure. Tertiary butylcyclopentadiene is obtained in this way, Kr.28 450 C, yield 304 / o.

Example 9 The procedure described in Example 1 is repeated, however, instead of 556 parts of tertiary butyl chloride, 895 parts of 3-chloro-3-methylheptane are used used. This gives (l-methyl-l-ethylamyl) -cyclopentadiene, boiling point ,,, 400C, Yield 3101o.

Protection is required for the preparation of the metal cyclopentadienyl compounds not claimed within the scope of the present invention.

Claims (4)

PATENT CLAIMS 1. Process for the preparation of tertiary alkylcyclopentadienes of the general formula wherein R ', R "and R"' denote alkyl radicals, in particular those of which either each contains up to 8 carbon atoms or in which the radicals R ', R "and R"' together contain no more than 8 carbon atoms, characterized in that that either a cyclopentadienyl magnesium halide or a cyclopentadienyl zinc halide or: dicyclopentadienyl magnesium or manganese, advantageously in the presence of one or more inert diluents or solvents, is reacted with a tertiary alkyl halide in a known manner. 2. The method according to claim 1, characterized in that as a tertiary Alkyl halide tertiary butyl chloride, tertiary amyl chloride or 3-chloro-3-methylpentane is used. 3. The method according to claim 1 and 2, characterized in that as Cyclopentadienyl magnesium halide, the cyclopentadienyl magnesium bromide and as cyclopentadienyl zinc halide the cyclopentadienyl zinc chloride is used. 4. The method according to claim 1 to 3, characterized in that as inert diluent or solvent diethyl ether, tetrahydrofuran or di-n-butyl ether is used. Documents considered: Dear. Ann. d. Chem., Vol. 524, 1936, p. 145.