DE1287080B - Process for the production of alkoxy olefins - Google Patents

Description

The invention relates to a new process for the preparation of alkoxyolefins of the general formula I. In this formula, R1 is a lower alkyl radical, R2 is a hydrogen atom or a lower alkyl radical, R3 is a hydrogen atom, an alkyl radical which is optionally mono by halogen atoms, alkoxy, aralkoxy, aryloxy, carbalkoxy or aminocarbonyl groups or by a free or by alkyl radicals - Or disubstituted amino group, where the nitrogen atom of the amino group can also be a member of a saturated heterocyclic ring, which can optionally be substituted by lower alkyl radicals, an alkenyl, aralkyl, aralkenyl, aryl or heteroaryl radical or, if R4 is one Carbalkoxy or aminocarbonyl group means, also an alkoxy radical, R4 an acyl, carbalkoxy or aminocarbonyl group, one of the groups mentioned under R3 or together with R3 and the intermediate carbon atom a mono- or polycarbocyclic or a monoheterocyclic ring system, R5 a nitrile group, a carbalkoxy group , an aminocarbonyl or hydrazi nocarbonyl radical, where the nitrogen atoms of the last two radicals are substituted by alkyl, alkenyl, aralkyl, aralkenyl, aryl or heteroaryl radicals or can be members of a heterocyclic ring optionally containing another heteroatom, both nitrogen atoms of the hydrazino group together being members of one 5- to 7-membered heterocyclic ring, an acyl radical or an aromatic ring and n the numbers 0, 1 or 2.

In the above definition, the acyl radicals are more aliphatic radicals aromatic or heteroaromatic carboxylic acids, among heteroaryl radicals are for example Pyridine, furan, thiophene, quinoline, pyrrole, thiazole, indole or thionaphthene rings to be understood under heterocyclic radicals, for example pyrazole, piperidine, Dihydropyran, tetrahydropyran, tetrahydropyridine, tetrahydroquinoline, tetrahydrofuran or hexahydrocarhazole rings.

According to the invention, the new compounds are obtained by converting a phosphonic acid ester of the general formula in which R1, R2, R5 and n have the meanings given and R represents a lower alkyl radical, into its carbanion and subsequent reaction with a compound of the formula in which R3 and R4 have the meanings given.

The conversion of the phosphonic ester of the formula II into its carbanion takes place using an anhydrous inorganic base in an anhydrous solvent preferably at a temperature between 20 and 130 "C. Come as anhydrous bases in particular alkali metals, alkali hydrides, alkali amides or alkali alcoholates in Question, of the latter, in particular, potassium tert-butoxide and sodium methylate have been found and sodium ethylate proved suitable. As anhydrous solvents are in particular Diethyl ether, tetrahydrofuran, dimethoxyethane, dioxane, benzene, toluene and dimethylformamide suitable.

The carbanions obtained in this way do not need to be isolated, but the solutions obtained are advantageous directly to the Oxove. binding of the formula III, expediently in the equimolar amount, in an anhydrous solvent implemented. The reaction will depend on the reactivity of the oxo compound Temperatures between room temperature and 130 "C for a period of one half an hour to several days. As an anhydrous solvent those mentioned in connection with the preparation of the carbanion come into question; becomes appropriate Of course, such a solvent is chosen whose boiling point is about the required Corresponds to reaction temperature. If the compound of the formula III is an aldehyde, then the reaction generally takes place at room temperature, often even exothermic. When reacting with ketones, the reaction conditions are generally more severe required, sterically hindered ketones such as benzophenone are particularly difficult to react.

The alkoxyolefins obtained are formed from the one formed at the same time water-soluble alkali dialkyl phosphate in a simple manner by adding water - and extraction of the aqueous layer with a water-immiscible organic Solvent separated. After the solvent has been separated off and distilled off the compounds are purified either by crystallization or by vacuum distillation. The yields are on average between 50 and 80,010, even sterically very high hindered ketones still give yields of around 30,010.

The alkoxyphosphonic diesters of the formula II used as starting compounds and not previously described in the literature are prepared starting from acetals of the formula in which R1, R2, Rr, and n have the meanings given, via the corresponding acetal halides in which one R1O group of the formula IV is replaced by chlorine or bromine, by reaction with trialkyl phosphite (Arbusov reaction) or by reaction with Alkali dialkyl phosphite (Michaelis-Becker reaction); the yields of the reaction, which proceeds smoothly in all cases, are between 50 and 800%. Instead of the acetals of the formula IV, one can also start from the corresponding E {albacetals.

In this way, the following α-alkoxyphosphonates, among others, were produced Manufactured: Ethoxy-cyano-methylene-phosphonic acid diethyl ester, diethylphosphono-ethoxy-acetic acid-ethyl ester Diethylphosphono-ethoxy-acetic acid-amide, diethylphosphono-ethoxy-acetic acid-N-methyl-amide, Diethylphosphono-ethoxy-acetic acid-N-ethyl-amideb Diethylphosphono-ethoxy-acetic acid-N-n-butyl-amide, Diethylphosphono-ethoxy-acetic acid-N-methyl-anilide, diethylphosphono-ethoxy-acetic acid-N-dimethyl-amide, Diethylphosphono-ethoxy-acetic acid-N-diethyl-amide, diethylphosphono-ethoxy-acetic acid-N-diallyl-amide, Diethylphosphono-ethoxy-acetic acid pyrrolidide, diethylphosphono-ethoxy-acetic acid piperidide, Diethylphosphono-ethoxy-acetic acid morpholide, diethylphosphono-ethoxy-acetic acid-4-acetyl-piperazid, Diethylphosphono-ethoxy-acetic acid-4-benzoyl-piperazid, diethylphosphono-ethoxy-acetic acid-4-carbethoxy-piperazide, Diethylphosphono-ethoxy-acetic acid-N ', N'-diphenylhydrazide, diethylphosphono-ethoxy-acetic acid-N'N'-dimethylhydrazide, 1-diethylphosphono-1-methoxy-acetone, α-ethoxybenzyl-phosphonic acid diethyl ester 1-Diethylphosphono-1-ethoxy-3-phenylpropene- (2), 4-diethylphosphono-4-ethoxy-3-methylcrotonic acid ethyl ester.

The following carbonyl compounds are particularly useful for the reaction according to the invention of formula III in question: formaldehyde, chloroacetaldehyde, chloral, isobutyraldehyde, Citral, ß-Cyclo-citral, ß-Jonylidenacetaldehyd, Benzaldehyde, 2-, 3- and 4-Methoxybenzaldehyd, 3,4-dimethoxybenzaldehyde, p-acetoxybenzaldehyde, p-dimethylaminobenzaldehyde, 3,4,5-trimethoxybenzaldehyde, Phenylacetaldehyde, cinnamaldehyde, 4-pyridinaldehyde, furfural, 5-nitrofurfural, 2H-S, b-dihydro-pyran-3-aldehyde.

Acerton, 6-methyl-5-hepten-2-one, cyclopentanone, cyclohexanone, 2-methylcyclohexanone, Cycloheptanone, cyclooctanone, cholestan-3-one, tetrahydro-γ-pyrone, 2,6-dimethyl-tetrahydro-γ-pyrone, Tetrahydro-thia-γ-pyrone, 1-methyl-4-piperidone, 1-benzyl-2,6-diphenyl-4-piperidone, 1-benzoyl-4-piperidone, 1-benzyl-4-quinolone, p-ionone, 6-methyl-3,5-heptadien-2-one, Acetophenone, benzophenone, 4-chlorobenzophenone, benzil, 2- and 4-benzoyl-pyridine, N - acetyl - acridon, N - methyl - acridon, xanthone, thiaxanthone, dibenzo [b, f] -cyclohepten-11-one, Dibenzo [b, f] - cycloheptan - 11 - one, morphanthridone.

5 - methyl - 5,6 - dihydro - morphanthridone, 5 - acetyl-5,6-dihydro-morphanthridone, 11 H - dibenzo [c, f] - [1,2-diazepine-11 6, 6,7-dihydro-5H-benzocyclohepten-5-one, 6,7,8,9-tetrahydro- H-cyclohepten-5-one, 6H-benzocyclohepten-6-one, 7H-benzocyclohepten-6-one, 3H-2-benzazepin-4-one, 2,3,4,5-Tetrahydro-3-methyl-1 H-3-benzazepin-1-one, 1 H-1, 5-benzodiazepin-3-one, 2, 3, 4, tetrahydro - 1 - methyl-1H - 1,5-benzodiazepin-3 1-methyl-hexahydroazepin-3-one, 1 - methyl - hexahydroazepin - 4 - one, 1 - acetyl - hexahydroazpin - 3 - one, 1-acetylhexahydroazepin-4-one, Anthraquinone, oxalic acid diethyl ester, oxalic acid monoethyl ester monoamide, oxalic acid monoethyl ester monopiperidide, Ethyl pyruvate, chloroacetone, 1,1-dimethoxyacetone, ß-formylcrotonic acid ethyl ester.

The new method is therefore extremely versatile and opens up starting from easily accessible raw materials, a simple and economical one Way of producing numerous new alkoxyolefins, which are important intermediates for the most diverse organic syntheses, especially Rur the syntheses of Represent remedies and pesticides.

There have already been various processes for preparing alkoxyolefins known. Thus, L. Clais e n (Chem. Ber., 29, 2932 [1896]) produced α-ethoxyacrylic acid ethyl ester by splitting off ethanol from ethyl pyruvate diethylaceta, T. G r ö g e r and E. W a l d m a n n (monthly journals for chemistry, 89, 370 [1958]) won α-Alkoxy-cinnamic acid ester by condensation of aromatic aldehydes with α-Alkoxyacetic acid esters, H. P l i e n i n g e r and coworkers (Chem. Ber., 97, 1713 [1964]) obtained from triphenyl (alkoxycarbethoxymethylene) phosphorane and formaldehyde (and other aldehydes) α-alkoxyacrylic acid ethyl ester, if necessary still have a substituent in the A position. However, neither of these procedures is as generally applicable as the present proceedings: apart from that only in a few Cases usable method of C l a i s e n can be according to the method of P l i e n i n g e r only convert aldehydes, according to the method of G r ö g e r and W a l d m a n n only aromatic aldehydes.

Furthermore, from the German Auslegeschrift 1 108 219 was the special one In the case of a reaction of phosphonic acid esters with oxo compounds, one already reaction previously described for general use, and from the literature (see.

Tetrahedron, 15, 959 (1963) and Chem. Ber., 97, 2011 [1964]) die Carbonyl olefination on steroids by means of alkoxycarbonylmethane-phosphonic acid dialkyl esters known, but this creates the corresponding alkoxycarbonylmethylene compounds.

However, as already mentioned, the method according to the invention is for all aldehydes and ketones and for a number of those falling under the formula III Esters and amides applicable, the only requirement is that, as from the general Formula emerges, R5 is a radical capable of accepting a negative charge represents.

Another advantage over the "alkoxyylide" process of P1 i e n i n g e r is that instead of that obtained there as a by-product water-insoluble triphenylphosphine oxide a water-soluble alkali dialkyl phosphate is obtained as a by-product which can easily be separated off in the manner described can, so that the alkoxyolefins of Formula 1 mostly through one-offs Distillation or crystallization can be obtained neat.

Finally, the stability of the α-alkoxy-phosphonic ester carbanions of the formula V is important in which the radicals R, R1, R2, R5 and n have the meanings given, quite surprising and by no means predictable. The stability of this anion depends largely on the character of the substituents on the carbon atom that bears the negative charge. An alkoxy group on the a-carbon atom significantly disrupts the resonance stabilization of the anion with its electron-donating effect. Rather, it was to be expected that the carbanion would either undergo α-elimination (U. Schöllkopf and M. Eistert, Ann., 664, 76 [1963]), under β-elimination or isomerization, or under ether cleavage (G.W. ittig and L. Lohmann, Ann., 550, 260 [1942]; CR H auser and SW K antor, J. Am.

Chem. Soc., 73, 1437 [1951]).

Nevertheless, the olefination according to the invention with α-alkoxy-phosphonic acid diesters results of the formula II, the desired compounds in a simple manner and in high yields Formula 1. This is all the more surprising since W itt i g and colleagues (cf. Chem. Ber., 95, 2514 and 2515 [1962]) the corresponding olefination with the lowest Homologues of a compound of the formula II, the methoxymethyl phosphonic acid ester, did not succeed.

The following examples serve to explain the invention in more detail.

Olefinations with diethylphosphonoäthoxyessigsäure-ethyl ester example 1 2.4 g of 50% strength NaHII suspension were washed free of oil with anhydrous ether and covered in a reaction flask with 100 ml of anhydrous dioxane. To the at 40 to 60 ° C stirred NaH / dioxane solution, 13.4 g of diethylphosphonoethoxyacetic acid ethyl ester were obtained given. After about 30 minutes the evolution of H2 was complete and clear Sodium phosphonate solution emerged.

(At 20 ° C, the evolution of H2 took much longer.) About this one The solution at 20 ° C. was a suspension of 7.2 g of paraformaldehyde in a few milliliters Given dioxane. A brown, syrupy precipitate separated out in an exothermic reaction from (sodium ethyl phosphate). After standing overnight at 205C, it was worked up “as usual”.

“Customary work-up” is understood to mean the following: 1. Addition from 100 to 300 ml of water (usually 200 ml) to the reaction mixture.

2. Add ether and separate the organic layer.

3. Extract the aqueous layer three times with ether (total 400 to 800 ml).

4. Drying of the combined extracts over Na2SO4 and evaporation of the organic solvent at 10 Torr and at 20 to 60 ° C.

5. Distillation of the crude product.

The distillation gave 4.2 g of 2-ethoxyacrylic acid ethyl ester of bp. 13: 74 to 77 ° C.

Example 2 To a sodium phosphonate solution as in Example 1 were 3.6 g of isobutyraldehyde given at 20 "C. In an exothermic reaction, a brown, syrupy precipitate. After standing overnight at 20 ° C., work-up was carried out as usual.

Crude product: 10.0 g.

The distillation gave 5.1 g of ethyl 2-ethoxy-4-methyl-2-pentenoate from bp-12: 87 to 89 ° C.

Example 3 To a sodium phosphonate solution as in Example 1 were 6.0 g of phenylacetaldehyde (freshly distilled) were added dropwise at 20 ° C. In exothermic A yellow, syrupy precipitate separated out. After standing overnight at 20 ° C was worked up as usual. Crude product: 10.9 g.

The distillation gave 4.6 g of ethyl 2-ethoxy-4-phenylcrotonate of bp 0.005: 83 "C.

Example 4 To a sodium phosphonate solution as in Example 1 were given 7.6 g of citral at 20 ° C. A brown syrup separated in an exothermic reaction away. After standing overnight at 20 ° C., it was worked up as usual. Raw product: 13.7 g.

The distillation gave 10.2 g of 2-ethoxy-5, 9-dimethyl-2,4,8-decatriene-carboxylic acid ethyl ester from bp-0.1: 95 to 105 ° C.

Example 5 To a sodium phosphonate solution as in Example 1, but in anhydrous tetrahydrofuran instead of dioxane, 5.6 g of 5,6-dihydro-2H-pyran-3-aldehyde were obtained at 205C admitted. Exothermic reaction. After standing for 3 days at 20 ° C., work-up was carried out as usual. Crude product: 11.0 g.

The distillation gave 5.9 g of a-ethoxy-ß- (5,6-dihydro-2H-pyran-3- yl) - ethyl acrylate with a boiling point of 0.01: 79 to 80 ° C.

Example 6 To a sodium phosphonate solution as in Example 1 were 5.3 g of benzaldehyde (freshly distilled) were added dropwise at 20 ° C. The strongly exothermic The reaction was moderated somewhat by cooling with water.

A brown syrup precipitates. The reaction solution became 30 minutes heated to 50 ° C., then cooled and worked up as usual.

The distillation of the crude product gave 6.7 g of a-ethoxy-cinnamic acid ethyl ester from bp-0.005: 85 to 92 ° C.

Example 7 To a sodium phosphonate solution as in Example 1, but in tetrahydrofuran instead of dioxane, 5.4 g of freshly distilled pyridinaldehyde were obtained at 20 ° C admitted. A syrupy precipitate separated out in an exothermic reaction. To 3 day Standing at 205C was worked up as usual.

Crude product: 12.1 g.

The distillation gave 6.1 g of ithoxy-1S- (4-pyridyl) acrylic acid ethyl ester from bp: 85 to 89 ° C.

Example 8 To a sodium phosphonate solution as in Example 1, but in tetrahydrofuran instead of dioxane, 6.6 g of cinnamaldehyde were added at 20 ° C. In exothermic reaction, a syrupy precipitate separated out. After standing for 3 days Work-up was carried out as usual at 20 ° C. Residue: 13.0 g.

The distillation gave 6.7 g of ethyl 2-ethoxy-5-phenyl-2,4-pentadienoate from bp-0.01: 107 to 1110C.

Example 9 To a sodium phosphonate solution as in Example 1, but in 1,2-dimethoxyethane instead of dioxane, 7.5 g of p - dimethylamino - benzaldehyde given. The reaction was exothermic. After standing for 3 days at 20 ° C worked up as usual. Crude product: 14.2 g.

The distillation gave 9.7 g of 2-ethoxy-3- (p-dimethylaminophenyl) - Acrylic acid ethyl ester (Kpo.ol: 123 to 1300C), which partially crystallizes.

Example 10 To a sodium phosphonate solution as in Example 1 were 6.3 g of 6-methyl-5-hepten-2-one were added at 20 ° C. After 3 hours of stirring at 80 ° C and Standing overnight was worked up as usual. Residue: 17.8 g.

The distillation yielded 7.4 g of ethyl 2-itthoxygeranate from bp: 60 to 65 ° C.

Example 11 To a solution of sodium phosphonate as in the example 1 4.2 g of cyclopentanone were added at 20 "C. The reaction was exothermic. After standing Work-up was carried out as usual overnight at 20 ° C.

The distillation of the crude product gave 2.4 g of ethyl 2-ethoxy-2-cyclopentylideneacetate from bp-0.01: 46 to 475C.

Example 12 As in Example 1, a sodium phosphonate solution was obtained given at 20 ° C 4.9 g of cyclohexanone. An exothermic reaction took place. To Heating for 30 minutes at 50 ° C and standing overnight at 20 "C became as usual worked up.

The distillation of the residue gave 5.7 g of 2-ethoxy-2-cyclohexylidene-acetic acid ethyl ester from bp-0.05: 57 to 62 ° C.

Example 13 As in Example 1, a sodium phosphonate solution was obtained 5.7 g of N-methyl-γ-piperidone (freshly distilled) were added at 20 ° C. It found one exothermic reaction takes place. After heating at 50 ° C for 30 minutes and standing over Work-up was carried out as usual overnight at 20.degree. Crude product: 11.0 g.

The distillation gave 5.7 g of 2-ethoxy-2- (N-methyl-γ-piperidinylidene) -acetic acid ethyl ester from bp-0.03: 64 to 66 ° C.

Example 14 As in Example 1, a sodium phosphonate solution was obtained added 5.6 g of 2-methyl-cyclohexanone (freshly distilled) at 20 ° C. There was none noticeable reaction. After 7 hours of heating at 80 ° C., the mixture was cooled down and as usual worked up.

2.3 g of α-ethoxy-α- (2-methyl-cyclohexylidene) -acetic acid ethyl ester were obtained from the crude product by distillation from bp-0.05; 54 to 56 ° C obtained.

Example 15 0.24 g of 50% NaH / oil suspension were added with a few milliliters anhydrous ether and washed oil-free in a carefully dried apparatus covered with 2 ml of anhydrous dimethylformamide. At 20 "C, 1.34 g of diethylphosphonoethoxy-acetic acid ethyl ester were obtained admitted. When a clear solution had formed, 387 mg of cholestan-3-one were added. After 17 hours of heating at 805C, the mixture was cooled and worked up as usual.

By plate layer chromatography of the residue on silica gel G nach Stahl with phosphor additive (eluent: benzene) were 150mg Cholestan-3- ylidene ethoxy acetic acid ethyl ester obtained. RF values: 0.41 (benzene) and 0.61 (Chloroform).

For comparison: RF values of 3-cholestanone 0.21 (benzene), 0.54 (chloroform). UV absorption at 238 to 240 mp, IR bands at 1700 and 1625 cm-1, NMR: one each Quadruplet at 3.55 and 4.15 ppm (2-O-CH2 groups) and typical steroid signals between 2 and 0.6 ppm.

Example 16 A clear solution of 5.6 g of potassium t-butoxide and 13.4 g g of diethylphosphono-a-ethoxy-acetic acid ethyl ester in 100 ml of anhydrous benzene 9.6 g of β-ionone were added at 20 ° C. and the mixture was then heated at 50 ° C. for 5 hours. After standing overnight, it was worked up as usual.

The distillation gave 2.6 g of 2-ethoxy-2- (ßiony liden) -acetic acid ethyl ester from bp-0.01: 97 to 100 ° C.

Example 17 As in Example 1, a sodium phosphonate solution was obtained given 6.0 g of acetophenone at 20 ° C.

The mixture was stirred at 80 ° C. for 8 hours, then cooled and as usual worked up. Raw product: 11.0g.

The distillation gave 6.8 g of ethyl 2-ethoxy-3-methylcinnamate from bp-0.1: 73 to 77 ° C.

Example 18 To a solution of 6.8 g of potassium t-butoxide and 13.4 g Diethylphosphono-ethoxyacetic acid ethyl ester in 100 ml of anhydrous toluene were given 4.2 g of benzil at 20 ° C. An exothermic reaction ensued. After heating Working up to 80 ° C. for 1.5 hours and standing overnight at 20 ° C. was carried out as usual.

4.6 g of ethyl 2-ethoxy-3-benzoyl-cinnamate were obtained from the crude product by distillation from bp-0.01: 130 to 137 ° C obtained.

Example 19 To a solution of sodium phosphonate as in the example 1, but in anhydrous dimethylformamide instead of dioxane, were 9.1 at 20 ° C g benzophenone given. After 30 hours of heating at 90 ° C., the mixture was cooled and how usually worked up.

Distillation of the crude product yielded 4.0 g of ethyl 2-ethoxy-3-phenyl-cinnamate from bp o l: 126 to 127 ° C.

Example 20 As in Example 1, a sodium phosphonate solution was obtained 5.9 g of 1,1-dimethoxy-acetone were added at 20 ° C. An exothermic reaction ensued.

After standing overnight at 20 ° C., it was worked up as usual.

The distillation gave 7.0 g of 2-ethoxy-4,4-dimethoxy-3-methylcrotonic acid ethyl ester from bp 12: 120 to 125 ° C.

Example 21 As in Example 1, a sodium phosphonate solution was obtained 7.3 g of oxalic acid diethyl ester were added at 20 "C. After 6 hours of heating to 80.degree and standing overnight was worked up as usual.

Distillation of the crude product (11 g) yielded 4.8 g of 2,3-diethoxy - Fumaric acid - ethyl ester with a boiling point of 0.005: 76 to 82 ° C.

Example 22 To a solution of sodium ethylate (freshly prepared from 1.15 g Na) and 13.4 g diethylphosphonoethoxy-acetic acid ethyl ester (I) in 100 ml 5.3 g of benzaldehyde (freshly distilled) were added to anhydrous dioxane at 20 "C. After 2 hours of heating at 50 ° C and standing overnight at 20 ° C, as usual worked up.

The distillation gave 3.0 g of ethyl 2-ethoxy-cinnamate with a boiling point of 0.1: 80 to 86 ° C.

Example 23 To a solution of 5.6 g of potassium t-butoxide and 13.4 g (1) In 100 ml of anhydrous dimethylformamide, 5.3 g of benzaldehyde (fresh distilled) given. After 2 hours of heating at 50 ° C and standing overnight 20 ° C was worked up as usual. The distillation yielded 8.5 g of ethyl 2-ethoxy-cinnamate from bp-0.1: 85 to 92 ° C.

Example 24 To a solution of 5.6 g of potassium t-butoxide and 13.4 g (1) in 100 ml of anhydrous benzene were 5.3 g of benzaldehyde (freshly distilled) given. An exothermic reaction took place. After 2 hours of heating at 50 ° C and standing Working up was carried out as usual overnight at 20 ° C. Distillation gave 6.6 g of ethyl 2-ethoxy-cinnamate with a boiling point of 0.05: 83 to 86 ° C.

Example 25 To a solution of 1.95 g of sodium amide and 13.4 g of (1) in 100 ml of anhydrous 1,2-dimethoxyethane, 5.3 g of benzaldehyde (fresh distilled) given. After 2 hours of heating at 60 ° C and standing for 48 hours at 20 ° C was worked up as usual. The distillation yielded 7.0 g of ethyl 2-ethoxy-cinnamate from bp-0.01: 78 to 82 ° C.

Example 26 To a sodium phosphonate solution prepared from 1.15 g Sodium and 13.4 g (1) in 100 ml of dioxane were given 5.3 g of benzaldehyde at 20 ° C. After stirring for 1 hour at 50 ° C., the mixture was cooled and worked up as usual.

The distillation gave 4.5 g of ethyl 2-ethoxy-cinnamate Kp.o.u5: 84 to 87 -C.

Olefination with 1-diethylphosphonol-methoxyacetone- (II) example 27 2. 40 g of 50% strength NaH / oil suspension were washed free of oil with anhydrous ether and covered in a reaction flask with 100 ml of anhydrous dioxane. To the NaH / dioxane suspension 11.2 g (II) were given at 20 to 40 ° C. After the H2 evolution ceased, 3.6 g of isobutyraldehyde, dissolved in 4 ml of dioxane, were added at 20 to 35.degree.

After about 30 minutes a brown syrupy precipitate separated out away. It was left to stand for 3 hours and worked up as in Example 1.

The distillation of the crude product gave 1.4 g of 3-methoxy-5-methyl-3-hexen-2-one from Kp.lo: 53 to 35 C.

Example 28 To a sodium phosphonate solution as in Example 27 were added 6.0 g of phenylacetaldehyde (freshly distilled) were added dropwise. There was a weak exothermic reaction. After standing at 20 ° C. for 3 hours, work-up was carried out as usual.

The distillation yielded 3.6 g of 3-methoxy-5-phenyl-3-pentan-2-one from bp-0.005: 62 to 65 C.

Example 29 To a sodium phosphonate solution as in Example 27 were added 10.6 g of benzaldehyde (freshly distilled) were slowly added dropwise. An exothermic occurred Reaction. After stirring for 2 hours at 20 ° C., the mixture was worked up as usual.

Distillation of the crude product gave 5.3 g of 2-methoxy-1,5-diphenyl-1,4-pentadien-3-one from b.p .: 149 to 153 "C.

In this case, the actual reaction product 2-methoxy-l-phenyl- 1-buten-3-one with a further equivalent of benzaldehyde to give the final product.

Example 30 To double the amount of sodium phosphonate solution as in Example 27 slowly became a solution of 33 g of p-acetoxybenzaldehyde (freshly distilled) dripped in a few milliliters of dioxane.

An exothermic reaction ensued. After 3 hours of stirring at 20 ° C was worked up as usual (double the amount of water).

Short-path distillation of the crude product yielded 17.1 g of the fraction 1 (bath temperature up to 120 "C at 0.1 Torr) and 16.4 g fraction 2 (bath temperature up to 200 @ C / 0.1 Torr). Fraction 2 crystallized [F. = 65 to 68 ° C from benzene and petroleum ether (40 to 60 "C), 9.5 g] and was found to be 2-methoxy-1- (p-acetoxyphenyl) -! - huten-3-one.

Example 31 To a sodium phosphonate solution as in Example 27 were added 5.7 g of N-methyl -'-piperidone were added.

After 2 hours of stirring at 80 ° C. and 60 hours of standing at 20 ° C., the mixture was added worked up as usual.

1.3 g of 1- (N-methyl-γ-ipieridylidene) -1-methoxy-2-pripanone were obtained by distillation of b.p. 0.01: 36 ° C.

Olefination with diethylphosphono-ethoxyacetic acid piperidide (III) Example 32 2.4 g of 50% strength NaHfOl suspension were washed oil-free, with 100 ml anhydrous Covered dioxane, 15.6 g (III) were added at 60 to 80 ° C. and the mixture was stirred for 1 hour. 5.3 g of benzaldehyde (freshly distilled) were added to the sodium phosphonate solution. After stirring at 100 ° C. for 2 hours and standing at 20 ° C. for 20 hours, the procedure was as usual worked up.

The distillation of the crude product yielded 6 g of thoxycinnamic acid piperidide from bp-0.005: 116 to 118 C.

Olefination with diethylphosphono-ethoxyacetic acid amide (IV) example 33 2.40 g of 50% NaH / oil suspension were washed oil-free, with 100 ml anhydrous Covered dimethylformamide and mixed with 12 g (IV) in three portions. To the clear one Sodium phosphonate solution was added to 5.3 g of benzaldehyde (freshly distilled). It an exothermic reaction took place.

After stirring at 50 ° C. for 2 hours, the mixture was cooled with ice and with 200 ml Water added. The resulting colorless precipitate was separated off with water washed and dried.

Yield: 5.5 g of α-ethoxycinnamic acid amide with a melting point of 143 to 148 ° C.

Olefination with (t-ethoxy-benzyl-phosphonic acid diethyl ester (V) example 34 2.40 g of 50% NaH / oil suspension were washed oil-free, with 100 ml anhydrous Dioxane, 13.6 g (V) and 5.3 g benzaldehyde (freshly distilled) are added. When warming at 100 to 120 ° C there was violent evolution of H2. It found an exothermic reaction instead of. After stirring for 2 hours without further heating, work-up was carried out as usual.

The distillation gave 5.7 g of α-ethoxy-stilbene with a boiling point of 0.005: 82 to 85 C.

Olefinations with l-diethylphosphono-l-ethoxy-3-phenyl-2-propene (VI) Example 35 2.4 g of 500h> NaH / Ell suspension were washed free of oil and covered with 100 ml of anhydrous dioxane. To the NaH / dioxane suspension stirred at 80.degree quickly became a solution of 5.3 g of benzaldehyde (freshly distilled) and 14.9 g (VI) added in a little dioxane. A violent exothermic reaction occurred after a few minutes a.

A clear solution was formed within 15 minutes and then a syrupy one Precipitation fell out.

After stirring at 80 ° C. for 1.5 hours, the mixture was cooled and worked up as usual.

The distillation gave 7.8 g of 2-ethoxy-1,4-diphenyl-butadiene vom Bp: 130 to 131 ° C.

Example 36 To a NaH / dioxane suspension as in Example 35 was added a solution of 4.9 g of cyclohexanone and 14.9 g of (VI) in a little dioxane is added at 80 ° C. A clear solution had formed after 1.5 hours. It was another 5 hours at Stirred at 80 ° C., then cooled and worked up as usual.

The distillation gave 7.0 g of 1-ethoxy-1-cyclohexylidene-3-phenyl-2-propene from bp-0.05: 105 ° C and mp 48 to 49 ° C.

Olefination with 4-diethylphosphono-4-ethoxy-3-methyl-crotonic acid ethyl ester (VII) Example 37 2.4 g of 50% strength NaH / oil suspension were washed oil-free with 100 ml of anhydrous dioxane covered and mixed with 15.4 g (VII). At 90 to 100 ° C a clear solution formed within 30 minutes. 1.5 g of paraformaldehyde were added to this at 60 ° C given. Exothermic reaction. After stirring at 60 ° C. for 2 hours, the mixture was cooled and worked up as usual.

The distillation yielded 1.7 g of ethyl 4-ethoxy-3-methyl-2,4-pentadienoate from bp-0.05: 40 to 42 ° C.

Olefination with ethyl 4-diethylphosphono-4-ethoxy-3-methyl-crotonic acid (VII) Example 38 To a sodium phosphonate solution as in Example 37 were 60'C given 5.3 g of benzaldehyde (freshly distilled). Exothermic reaction. After 2 Hours of heating at 50 to 60 ° C was worked up as usual.

The distillation gave 5.1 g of ethyl 4-ethoxy-5-phenyl-3-methyl-2,4-pentadienoate of bp 0.005: 92 ° C, which was contaminated with a little phosphonic ester (VII).

Olefination with diethylphosphono-ethoxyacetic acid-ethyl ester (I) Example 39 To a sodium phosphonate solution as in Example 1 were 5.8 g pyruvic acid ethyl ester (freshly distilled) added. Exothermic reaction. After 15 hours of heating at 80 ° C., the mixture was cooled and worked up as usual.

The distillation gave 4.1 g of 2-ethoxy-3-methylfumaric acid diethyl ester from bp-0.01: 60 to 62 ° C.

Claims (1)

Claim: Process for the preparation of alkoxyolefins of the general formula l in which R1 is a lower alkyl radical, R2 is a hydrogen atom or a lower alkyl radical, R: l is a hydrogen atom, an alkyl radical, optionally mono by halogen atoms, alkoxy, aralkoxy, aryloxy, carbalkoxy or aminocarbonyl groups or by a free or by alkyl radicals - Or disubstituted amino group, where the nitrogen atom of the amino group can also be a member of a saturated heterocyclic ring, which can optionally be substituted by lower alkyl radicals, an alkenyl, aralkyl, aralkenyl, aryl or heteroaryl radical or, if R4 is a Carbalkaxy or aminocarbonyl group means, also an alkoxy radical, R4 an acyl, carbaikoxy or aminocarbonyl group, one of the groups mentioned under R3 or together with R3 and the intermediate carbon atom a mono- or polycarbocyclic or a monoheterocyclic ring system, Rs a nitrile group, a carbalkoxy group , an aminocarbonyl or hydrazinocarbonyl radical, w whether the nitrogen atoms of the last two radicals are substituted by alkyl, alkenyl, aralkyl, aralkenyl, aryl or heteroaryl radicals or can also be members of a heterocyclic ring optionally containing another heteroatom, with both nitrogen atoms of the hydrazino group together members of a 5- can be up to 7-membered heterocyclic ring, an acyl radical or an aromatic ring and n denotes the number 0, 1 or 2, characterized in that a phosphonic ester of the general formula II in which R1, R2, Rg and n have the meanings given above and R is a lower alkyl radical, converted into a carbanion in an anhydrous organic solvent with an anhydrous inorganic base and this with a carbonyl compound of the formula III in which R3 - and R4 have the abovementioned meaning, is reacted in an anhydrous solvent, preferably at a temperature between 20 and 130 ° C., and the α-alkoxyolefin thus obtained is separated off in a known manner from the alkali dialkyl phosphate formed at the same time.