DE1468555A1 - Process for the production of monoolefins - Google Patents

Description

Process for the production of iv.o no olefinen

The present invention relates to a method of preparation of quaternary carbon atoms end containing eni.Ionoolefinaa.

üs has recently been found that olefins bciiüielapunkt with quaternary Kohlenoxoi'la ^ Oiiien valuable <fj olefins for uer st RECOVERY polymers with uoJaem or other desirable Eifeenscnaften are üo for example, in the book of Gaylord and Mark "linear and Stereoreßular addition polymer "(Interscience Publishers Inc., New York, 1959), page 64, describes that isotactic poly-3,3-dimethyl-1-butene having a melting point of about 149 was prepared. A copolymer of ethylene and 3,3-T) imethylenebutene-1 was also produced, using a conventional polymerisation catalyzed by peroxides, and the resultant polymerisation was lower than that of a polyethylene (see TJS patent specification 2 728 752) is more flexible and has an increase in stretchability of 300-500 ^ .

2 «eit l & z a.eia tecnnisoJi feasible procedure for the

8Ojä8 to, / 1 34.0

position of quaternary fc ^ oi-lenstolf atoms containing en monoolefins such as 3> 3 I> imetitylbuten-l known jiiner of these reasons is uem extremely unfavorable Oleichgewicht this Isjönoolefine in isomeric mixtures. Thus, for example, 3,3-dimethane-lbutene-1 is the least favored isomeric C -olefin at a temperature above 127. So, for example, leads to dehydration

of pinacolone alcohol only leads to a y-pig & n yield of 3> 3-dimethylbutene-1, which corresponds to the equilibrium value in a mixture of dimeth ^ lbutenes.

Usually, 3,3-Dimeth} lbutene-1 is produced by a long and circumstantial process A method made hot in which acetone is replaced by Aluiuiniumaüialfean dimerized to pinacon, this by treatment rearranged into the pinacolin with an acidic catalyst, this catalytically into the corresponding alcohol, i.e. the 3> 3-dimethyl -2-butanol, reduced, a xanthate or another suitable one Produces esters of alcohol and subjects them to thermal pyrolysis to produce 3,3-dimethylbutene-1. Dimethylbutene-1 was also produced by the pyrolysis of the stearic acid ester of 3,3-dimethyl-2-butanol (see "Fuel chemistry", 32, pp. 161-174, ((195I)). However, this process causes rearrangements in the chain, and so the undesirable isomers of the olefin, e.g. 2,3-dimethylbutene-1 and 2,3-l) imethylbutene-2. The formation of the isomers and the UiüStanalicne process make this production evident unsuitable for the technical production of 3 »3-dimeth, ylbutene-1.

. ^a BADORIQINAL -3-

809810/1340

The dehydrohalogenation of halogenated hydrocarbons to produce olefins is also known. So the division of monoolefins from monohalogenated normal paraffins is not bcjavri.erig. On the contrary, however, there are considerable difficulties. Dei the dehydrohalogenation of halogen-substituted Vferk.viöi ^ tjiettigea tarafiinen, especially in those which eri ^- iuaua ₆ s _& eiaais contain a neocarbon atom in the molecule. Compounds with the last-mentioned structure show a strong tendency to rearrangements in the chain during dehydrohalogenation, the Neo structure being largely changed and a substantial amount of isomers being formed. For example, in J. Am. Chem. Soc _i ^ _67 _JL __Page 1152j-54_. £ 1945) described that the dehydroChlorination of 1-chloro-3,3-dimethyTbutane gives a mixture of olefins which have a new carbon structure, that is, that the diethyl groups are now in the 2 and 3 positions. This dehydrochlorination was carried out in the presence of a catalyst at temperatures of 200-450 °.

JiS wurae now. found that according to the invention monoolefins with quaternary carbon atoms can be produced in high selective yields and practically without chain isomerization to other olefins with the same carbon number. This new method ^Λ esteht in the dehydrohalogenation of a selected feed material under certain reaction conditions.

The halocarbon feed of the present invention Procedure is characterized by the following formula:

- 4 809810 / 134Ö

in which R is an aliphatic monovalent hydrocarbon radical such as a lower alkyl radical including cycloalkyl radicals up to 8 carbon atoms, and the total number of carbon atoms in all radicals R is not more than 18, preferably not more than 12, and where R is optionally also substituted with branched chain or with non-interfering groups its kamu R * is a divalent aliphatic hydrocarbon radical with 2 to 8, preferably 2-4 carbon atoms, and X is a halogenate * m with an atomic weight of 35-127. The halogen is preferably on a carbon atom in the-position to the neo-carbon atom substituted. Ee is particularly preferred when the β-carbon atom is at one end of the carbon chain. _; Examples of useful feeds are 1-chloro-dimethylbutane, 1-chloro-3,3-dimethylpentane, and 2-chloro-4,4-dimethylpentane.

According to the invention, the charge is in vapor form of a temperature

o η absence

temperature of about 450-600, preferably 475-575, in ws subject to a catalyst. It is therefore essential that that new processes are not catalytic and practically carried out in the absence of acidic or basic materials, though a contact material is preferably also used in the dehydrohalogenation. In the same way, L-metal oxides with

- 5 809810/1 2LO

react to the hydrogen halide to an absolute minimum be maintained, so that a high selectivity in the dehydrohalogenation is maintained. Suitable contact materials are, for example, oxides, coke, etc. If a contact material is used, an IHSV (liquid hourly space velocity) of about 0-5-20, preferably 2-10, is used. The reaction can be carried out at atmospheric pressure, elevated pressure or reduced pressure, but a pressure of less than about 11 atmospheres. Optionally, an inert gas such as nitrogen or carbon dioxide can be used in the reaction and that inert gas can be used in a ratio of about 0 to 20 or more moles per mole of hydrogen chloride formed Find application. Under the conditions according to the invention, the Selectivity to the corresponding quaternary carbon atoms Moaoolefin increased greatly, and it did not become essential Amounts of olefins of similar carbon content, however without a keo carbon atom, found in the crude product.

The charge used can be used in a known manner Wise madeXlt ^ waiöen. So kaaa e.g. l-chloro-3t3-dimethyltutane according to the oln & n angigöbenen method in J. Am. Chem. Soc. hereditary

provides werdtm. $> ifrB '$ # · Y $ rfahar «n consists in that 1 KoI Ethyleft

with t-butyl |! hl ^ Vi4: 3 # ** r use of a Friedel-Crafta- £ atäi # r

eat or β, mim ^ jjfa,

I ''.: "It * υ

if

used

ÄtOX or ZnCl umgeeet ^ t

3 2.> -

Pressure carried out v

Temperature from

- O

Under the specified conditions, ie complete conversion, the yield of 1-chloro-3,3-dimethylbutane is 75 %. If a contact material is used, the feed should be practically dry and essentially free of acidic and basic materials. Fractionation in a single-filled column normally provides a chloride which is sufficiently pure for use in the process of the invention.

The following examples illustrate the invention.

A Vycor reactor was filled with demagnetized alumina - (* M> ul «nlumiial

and ο
quenched / heated to 480 with a stream of nitrogen being passed through. Then 1-chloro-3,3-dimethylbutane was fed in through a capillary from a calibrated container and the effluent from the reactor was condensed in a condenser with a "cold pinger" with dry ice. D * x hydrogen chloride was passed through nitrogen into a sodium hydroxide trap. After an alkaline wash, the reaction product was analyzed by gas chromatography to determine the relative amounts of the various olefins obtained, jbu. With a contact time of 2 seconds and a temperature of 460 ° -500 ° C., the chloride produced an olefin mixture

Ji "t tfS» 3WÄ »tfayl.bttten-l and

- 'fit prey

■ fii

vmet- j ^ Aktisoh quantitative,

- 7 - 14685F5

In a second experiment at 530 ° and 1 second contact time, the ratio was 2,3-D ± methylbutene-1 to 2,3-dimethylbutene-2 something eriioht. However, the yield of 3,3-dimeth.ylbutene-1 was not increased.

Example 2

A rock salt filling was used in place of the clay filling used in Example 1. There was also a contact time of about 2-3 seconds and the l-chlorine ~ 3,3-dimeth ^ lbutane split at four different temperatures. At a temperature of 450, the olefin obtained existed outside three Diniethylbutenisoeren in practically the same yields as obtained from clay. The subsequent attempts

however, at 530 and 590 gave olefins in high yields without

an isomerization of the carbon chain occurred. In these The only detectable Cg olefin was 3,3-dimethylbutene-1. At the higher temperature some C-C splitting occurred, with isobutylene and other low-boiling points Connections were formed.

Example 3

A Vycor reactor was filled with Eyrex grains and then in heated to 570 ° in an electric oven, whereupon l-chlorine ^ ·, 3-dimethyl but a η were introduced together with prepurified nitrogen as a diluent. The contact time was 2-4 seconds. Otherwise, the experiments were carried out as above. The results are listed in the table below.

IDSI ^ O / -) 3 AO " ⁸ ~

Table I.

saxi s jjescniK:
kung - Contact
Time Temp. σ ° / o conversion
lung fo 313-dimethyl
—I-butene-l in
Olefin fraction 1 O 4th 570 42 85 2 O 2 570 31 87 3 1 4th 570 45 86 4th 2 2 550 20 ⁺⁺ 78

+) The same chloride was used in all experiments. The number indicates how often the loading takes place. Vo *

++) Some olefin was lost during the distillation, and the Yield was corrected to compensate.

After the last attempt, what was recovered was not converted Examined chloride by infrared analysis and found that it is identical to the starting material.

Example 4

A Vycor reactor was filled with ceramic insulating balls and 1-chloro-3,3-dimethylbutane as in Example 3 dehydrochlorinated. The reaction conditions and the results are shown in Table II below.

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1050.1 Table II Reactor volume 26th _21 15.6 ecm 29 £ 2 22nd O 468555 Reactor filling CO 45.7 1050.0 1053.1 1 951.0 954.0 1005.0 τ— 22.78 »S» Approach No. 1141- 77.22 1052.3 244.3 17.9 91.5 2.01 91.5 O Average track 69.40 1.53 92.00 19.70 64.75 temperature ⁰ C 3.64 91.5 30.60 98.47 8.00 80.30 35.25 W.
O) Loading unit 44.40 track 2.99 Ceramic insulating grains and balls track track track O
CO speed ccm / hr. 57.90 55.60 0.735 2.17 22nd 0.238 9.20 1.57 Recovered CgCl track track 2.83 20.23 0.246 9.50 3.25 other products 1.34 2.69 24.70 49.30 001.5 6.77 45.45 27.00 Propylene 0.83 7.00 track 4.51 track 1.08 0.29 Isobutane - 38.30 0.606 4.08 12.3 track 0.90 0.24 Isobutylene track 1.67 track 2.79 11.90 track 2.22 track 3,3-DM-butene-1 10.13 0.69 1.80 88.10 0.212 1.38 - ι 2Me2C, ■ 3.36 0.21 track 0.036 track 0.528 2.69 0.48 ' Isoprene 22.78 - - - 6.50 • ° * 2,3-DM-butene-1 0.69 1.70 10.04 9.32 track 7.86 2.59 ' not identified - 69.40 1.53 56.30 92.00 19.70 64.75 2,3-DM-butene-2 track 4.38 1.89 t-butyl chloride 4.92 44.40 1.70 Vinyl chloride - track 3.39 1.67 track track track Chlorine-3,3-DM-butane 78.45 2.53 2.46 1.90 2.98 12.72 4.78 Selectivity, track track 9.79 22.90 2.72 3.08 13.14 9.90 Moles / 100 moles of feed 1.81 5.26 85.50 55.90 _ 84.68 63.00 82.40 Propylene 1.12 13.78 track 5.11 6.07 track 1.50 0.88 Isobutane 74.75 2.16 4.62 11.90 track 1.24 0.73 Isobutylene track 3.27 track 3.17 track 3.07 track 3,3-DM-butene-1 13.70 1.35 - 0.85 2.65 1.91 mm 2Me2C ₄ » 77.22 0.42 track 1.22 track 6.61 3.73 1.46 Isoprene 78.45 - - 7.93 - 2,3-DM-butene-1 1.35 30.60 98.47 11.38 8.00 80.30 35.25 not identified 85.50 55.90 68.70 84.68 63.00 52.40 2,3-DM-butene-2 55.60 2.31 t-butyl chloride 74.75 2.07 conversion 2.04 selectivity 2.32 3.31 88.10 68.70

Results of Examples 3 and 4 clearly show that invention ₆ emüi «3,5-Dimetia ^ lbutene-1 can be er-Jaaiten in honen selective yields, with - if, at all - only a few other C ^ -olines like 2,3 -Dimeth ^ lbutene-1 and 2,3 Dimeth ^ lbutene-2 are formed.

Example 5

In a large-scale batch for the production of 3,3-dimethylbutene-1, 81.6 kg of 1-chloro-3,3-dimethylbutane were transferred at a temperature of about 555 ° and an LHSV of 10 through a 2.5 cm Hast-Alloy universal reactor headed, which was filled with m: t ceramic balls. The product was gut ewascnen with water and with dilute Natrionlauge _ö what ever analysis of Honproduktes showed that this 40 Jb olefin entnält.

After the olefin fraction of the product through. Distillation had been removed, the unconverted chloride was returned to the reactor, and 38.6 kg of crude olefin was obtained. In a fraction of the olefin via calcium anhydride, 25.4 k {'. obtained a material that boiled at a Kajoft temperature of 40.5 °. Its infrared analysis showed that the purity of the 3,3-dimethylbate-oil was greater than 98 ^% . This means a yield of 66 yo Mol-Jfc.

Example 6

There were a total of 3 350 g of l-Chlcr ^^ - dimethylpentane in one

BATH ORIGINAL

80f) ßin / n /. η

146855F

Heating temperature of about 565 - 574 ° uaö an LHSV = 16 passed through a small quartz reactor, which was filled with ceramic grains. The fvFflv'd cvb of this reactor was placed in a small packed column to recover the hydrogen chloride, whereupon the olefin was removed by distillation and the unconverted chloride was returned to the reactor. After several passes through the reactor, all but 1150 g of olefin had been converted and a yield of 1220 g of a crude olefin of about 85% purity was obtained. After it had been fractionated over maleic anhydride for purification, then treated with dilute alkali and finally with sodium, 900 g of 3 »3-imethylpentane-1 with a purity of

ΰ7 P obtained. τ tr

Example 7 '

In an attempt in which l-chloro-3 »3-dimeth; ylbutane via a Quartz reactor, which was filled with helical stainless steel packing, was passed, entered an almost complete Conversion of the chloride into the olefin. The room temperature was about 480-540 °. Analysis of the product by gas chromatography showed that the main products 2,3-dimeth ^ lbutene-1 and 2,3-dimeth ^ lbutene-2 was. The high conversion as well as the extent of isomerization showed that the iron, presumably as perchloride, a deleterious catalytic ^ effect on the reaction. - as far as the formation of 3 »3-dimethylbutene-1 is concerned - exercises.

A second attempt, in which nickel shavings instead of iron

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were used, was practically only 3,3-Dimeth.ylbuten-1 with only trace amounts of other Cg olefins are obtained.

Example 8

A sample of 2-chloro-4,4-dimethylpentane obtained by alkylating t-butyl chloride with propylene was found at pyrolyzed about 455 ° with a 95 $ conversion and a nearly quantitative selectivity was obtained. The mixture obtained had the following analysis:

3,7 $ cis-4,4-dimethylpentene-2 73 »2 - / ο trans-4,4-dimeth, ylpentene-2 and 23> 1 ^ 4» 4-dimeth; ylpentene-1

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Claims (1)

Claims Process for the production of monoolefins with quaternary Carbon atom type "~ 3 ~ a marked by that a halogenated Hydrocarbon of the formula R I - R ¹ - CR in which R stands for an aliphatic or C ₀ cloaliphatic monovalent hydrocarbon radical with up to 8 carbon atoms, and the total number of carbon atoms in all radicals R is at most 18, R ^! is a divalent aliphatic hydrocarbon radical with 2-8 carbon atoms and X is a halogen atom with an atomic weight of 35-127, is thermally dehydrohalogenated in the presence of a non-catalytic contact material in vapor form at a temperature of about 450-600. Process according to Claim 1, characterized in that the instantaneous chlorohalogenation is carried out at a liquid hourly space velocity of 0.5-20. Method according to claims 1 and 2, characterized in that that a halide is used in which R ^{1 is} a radical having 2-4 carbon atoms. 809810/1340 Process according to Claims 1 and 2, characterized in that 1-chloro-3,3-dinieth, ylbutane is used as the halide. Method according to claim 1 to 4, characterized in that nickel is used as a non-catalytic contact material, Process according to Claims 1 to 4, characterized in that ceramic beads are used as the non-catalytic contact material
or balls can be used. The patent attorney 809810/1340