DE2132548C3 - Process for the preparation of acetals of 1,4-dicyano-2-formyl-butane - Google Patents

Description

in the presence of alkanols and cobalt carbonyl um- to proved.

puts.

The introduction of a formyl group in olefinic unsaturated compounds has long been used as a hydroformylation reaction or oxo reaction known. In addition to olefinically unsaturated hydrocarbons, there have also been olefinically unsaturated compounds with various functional ™ groups subjected to the hydroformylation reaction. It is from J. Falbe Carbon Monoxide in Organic Synhi Si

The reaction is carried out in the presence of cobalt carbonyl. Preferably one turns 0.1 to 1.5 percent by weight cobalt, calculated as metal, based on the 1,4-dicyanobutenes used, at. Amounts of 0.5 to LO percent by weight of cobalt have proven particularly useful. It is possible the carbonyl complexes to prepare separately before the oxo reaction or the starting materials for to feed the cobalt carbonyls, such as fatty acid salts or naphthenates of cobalt, separately to the reaction The catalyst then forms by itself under the reaction conditions.

A special feature of the process is that the reaction in the presence of alkanols as h id Bd bh

different solvents in a wide spectrum of reaction conditions possible. In the hydroformylation of higher unsaturated cyano compounds However, the yields left much to be desired, so that a technical realization such a procedure is very dubious.

As is known from our own experiments, the hydroformylation of 1,4-dicyanobutyr does not succeed €) without more. For example, rhodium

care products. Also the Hydro

lo.mylation of 1,4-dicyanobutene with cobalt carbo-HyI, modified by phosphines i: it, in tetrahydrofuran as a solvent results in addition to a unl

thesis, Springer-Verlag 1970, pp. 52 and 53 known, 35 solvent is carried out. Particularly proven that in the hydroformylation of acrylonitrile, alkanols with 1 to 6 carbon atoms, Allyl canide and others substituted with cyano groups, especially those with 1 to 4 carbon atoms, Tuted octinically unsaturated compounds. Suitable alkanols are, for example, methanol. speaking formylated. Connections. So propanol, ethanol, n-butanol, isobutanol or penist the hydroformylation of acrylonitrile in the tanol. Appropriately, one applies what is to be introduced

Equivalent of a formyl group at least 2 mol of alkanols. It is advantageous to use the Alkanols in excess, e.g. B. up to 300 mole percent.

It has also proven advantageous to carry out the reaction in the presence of polymerisation inhibitors. e.g. hydroquinone. Particularly good results are obtained when the reaction mixture 0.1 to 1 percent by weight of the

Adds carbonyl complexes also in connection with phosphate inhibitors.

phinen as modifiers. The method according to the invention is also used in the hydro

for example, by putting 1,4-dicyanbutenes together with suitable alkanols in a high pressure vessel together with the mentioned catalysts

Only dicyanobutane and amitators are presented to the distillable residue and the implementation is described in the case of r "en" butane as reaction products, while the hydrobene temperatures and pressures with carbon chloromylation monoxide and hydrogen of the specified composition only in the presence of cobalt carbonyl Tetrahydrofuran as a solvent only carries out composition. In suitable devices • results in an indestructible residue. the implementation can be continued without difficulties

It has been found that acetals of 1,4-5 "are made natural. After cooling and ent-dicyano-2-formylbutane, if 1,4-dicyclic pans, optionally after decomposition of the catalyst, the acetals of l 4-dicyano-2-formylbutans z. B. isolated by fractional distillation. unreacted starting materials are conveniently ⁵⁵ fed back to the reaction.

The acetals of 1,4-dicyano-2-formyl-butane according to the invention are used as follows:

The acetals of 1,4-dicyano-2-formyl-butane are too many due to their three functional groups Suitable for subsequent reactions. Acid saponification leads to the corresponding formyldicarboxylic acid, the oxidation of which yields a butane tricarboxylic acid. A reduction of the formyldicarboxylic acid lets a methylol dicarboxylic acid arise, which allows

mean in a volume ratio of 1: 4 to 4: 1 ^{an- 6s is} capable of two-fold lactone formation. A hydrogenation turned. A mixture of the acetals according to the invention has proven to be particularly useful, leading to a metus of carbon monoxide and hydrogen in the volume thylol-diamino-hexane or when using a ratio of 1: 2 to 2: 1. Ammonia is advantageously used to form a triamino-heptane.

Inbutene- (2) or - (1) with carbon monoxide and hydrogen at temperatures from 100 to 150 ° C and ■ nter pressures of 150 to 400 atm in the presence of alkanols and cobalt carbonyl.

The new process has the advantage that it is possible to obtain acetals of 1,4-dicyano-2-formyl-butane that have not been described before to produce, yielding yields which enable the process to be carried out on an industrial scale.

The starting materials used are 1,4-dicyanobutene- (l) and / or - (2). The starting materials can be in cis or trans form.

Carbon monoxide and hydrogen are generally

The polyfunctional compounds obtained can ζ. B. are used in surface-active formulations z. B. as a detergent additive (Tri- or hydroxydicarboxylic acid) or as intermediates for plastics.

The method according to the invention is illustrated in the following example.

example

100 g of methanol, 100 g 1,4-dicyanobutene (1) (cis and trans isomer), Submitted 3 g of dicobalt octacarbonyl and 1 g of hydroquinone. The pressure vessel is several times with a Iquimolecular mixture of carbon monoxide and hydrogen purged. Then it is heated to 140 ° C and at the same time the thickness by pressing on the said Gas mixture adjusted to 280 atm. Gas uptake has ended after about 10 hours. To After cooling, the reaction mixture is let down and fractionally distilled. 94 g of dimethyl acetal are obtained of 1 ^ -Dicyan ^ -formyl-butane with a boiling point of 120 to 124 ° C at 0.2 mm Hg. This corresponds to a yield of 55% of theory. The results of the elemental analysis agree with the calculated values for the empirical formula

ίο C9HUO2N2 match.

carbon
hydrogen
nitrogen

calculated 59.3%
calculated 7.7%
calculated 15.4%

found 59.6% found 7.7% found 15.0%

The mass spectrum shows a strong fragment of mass 151, which is responsible for the cleavage of a methoxyl group is characteristic.

Claims (1)

Claim: Process for the preparation of acetals of l, 4-dicyano-2-formy! -Butane, characterized in that that 1,4-dicyanobutene- (1) or - (2) with carbon monoxide and hydrogen at temperatures from 100 to 150 ° C and under pressures from 150 to 400 atm in Geman said mixture in excess, based on the starting materials used, e.g. B, up to Ten times the molar amount. The reaction is carried out at temperatures of 100 to 15O ^'J C. Particularly good results are obtained when temperatures of 120 to 140 ° C are used. Furthermore, pressures of 150 to 400 atm are used for the reaction. Pressures of 200 to 30U atm have proven particularly advantageous