CA1255696A - PROCESS FOR PREPARING .alpha.-ARYLACRYLONITRILES - Google Patents
PROCESS FOR PREPARING .alpha.-ARYLACRYLONITRILESInfo
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- CA1255696A CA1255696A CA000493065A CA493065A CA1255696A CA 1255696 A CA1255696 A CA 1255696A CA 000493065 A CA000493065 A CA 000493065A CA 493065 A CA493065 A CA 493065A CA 1255696 A CA1255696 A CA 1255696A
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- alpha
- alkali metal
- metal cyanide
- lewis acid
- aryl
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Abstract
ABSTRACT
PROCESS FOR PREPARING ALPHA-ARYLACRYLONITRILES
An alpha-arylacrylonitrile is prepared by reacting an aryl ketone having a removable hydrogen alpha to the carbonyl group with an alkali metal cyanide and a Lewis acid preferably in the presence of a solvent. In a preferred embodiment, the aryl ketone is a tetralone, the cyanide is sodium cyanide, the Lewis acid is aluminum chloride, and the product is a 1-cyano-3,4-dihydronaphthalene.
PROCESS FOR PREPARING ALPHA-ARYLACRYLONITRILES
An alpha-arylacrylonitrile is prepared by reacting an aryl ketone having a removable hydrogen alpha to the carbonyl group with an alkali metal cyanide and a Lewis acid preferably in the presence of a solvent. In a preferred embodiment, the aryl ketone is a tetralone, the cyanide is sodium cyanide, the Lewis acid is aluminum chloride, and the product is a 1-cyano-3,4-dihydronaphthalene.
Description
~55~96 Case 5447/5474 PROCESS FOR PREPARING ALPHA-ARYLACRYLONITRILES
-This invention relates to alpha-arylacrylonitriles and more particularly to a process for pre~aring them.
It is known that alpha-arylacrylonitriles are use-5 ful as chemical intermediates and that they can beprepared in various ways. For example, Jacobs et al., Journal of Organic Chemistry, 1983, Vol. 48, pp~
5134-5135, teach that 6-methoxy-1-cyano-3,4-dihydro-naphthalene is useful as an intermediate in the synthesis 10 of steroids and that it can be prepared by (1) the addition of diethylaluminum cyanide to 6-methoxytetralone followed by dehydration or (2) the addition of cyano-trimethylsilane to 6-methoxytetralone Eollowed by treatment with phosphoryl chloride in pyridine. As 15 taught by Jacobs et al., the former method of synthe-sizing their alpha-arylacrylonitrile is impractical for large scale operations, and the latter method requires two steps.
An object of this invention is to provide a novel 20 process for preparing alpha-arylacrylonitriles.
Another object is to provide such a process which is suitable for large scale operations and produces the alpha-arylacrylonitriles from aryl ketones in a single step.
~55~9~
These and other objects are attained by reacting an aryl ketone having a removable hydrogen alpha to the carbonyl group with an alkali metal cyanide and a Lewis acid.
Aryl ketones that can be used in the practice of the invention can be any aryl ketones having a removable hydrogen alpha to the carbonyl group. ~owever, they are generally aryl ketones corresponding to the formula Ar-C0-R wherein Ar ls aryl and R is a monovalent ali-phatic, cycloaliphatic, or aromatic group having a removable hydrogen in the alpha-position. In such ketones the Ar group is generally an aryl group contain-ing 6-20 carbons, most commonly a phenyl or naphthyl group which optionally bears one or more inert sub-stituents, i.e., substituents that do not inhibit theactivity of the Lewis acid in removing the removable hydrogen, such as alkyl, alkylthio, alkoxy, halo, nitro, etc. The R group is generally a saturated or unsaturated aliphatic, cycloaliphatic, or aromatic group containing 1-20 carbons, optionally bearing one or more inert substituents and sometimes joined with the Ar group to form a fused ring.
Exemplary of such ketones are phenyl alkyl ketones wherein the alkyl group is methyl, ethyl, propyl, iso-propyl, butyl, isobutyl, t-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, etc.; the corresponding substituted-phenyl alkyl ketones wherein the substituents on the benzene ring may be any of the aforementioned alkyl groups and/or the corresponding alkoxy or alkylthio groups, chloro, bromo, nitro, etc.; the corresponding naphthyl or substituted-naphthyl alkyl ketones; the corresponding aryl substituted-alkyl ketones wherein the substituents on the alkyl group may be any of afore-mentioned inert substituents; the corresponding aryl substituted-or-unsubstituted-cycloalkyl (e.g., cyclo-propyl, cyclobutyl, cyclohexyl, cyclooctyl, etc.)ketones; the corresponding aryl substituted~or-unsubstituted-alkenyl ketones wherein the unsaturation is at least olle carbon removed from the carbon bearing the removable hydrogen, such as ketones in which the alkenyl group is 2-butenyl, 3-hexenyl, 4-hexenyl, 4-octenyl, etc.;
the corresponding aryl substltuted-or-unsubstituted-cycloalkenyl ketones; the corresponding aryl substituted-or-unsubstituted-aromatic ketones wherein said aromatic group is benzyl, phenylethyl, phenylpropyl, etc., tetralone, etc. Among the prefèrred ketones are aceto-phenones, such as acetophenone, 4-chloroacetophenone, 4-isobutylacetophenone, 4-ethoxyacetophenone, etc., and tetralones, such as tetralone, 6-methoxytetralone, 7-bromotetralone, etc.
9~
The Lewis acid utilized in the reaction may be any suitable Lewis acid, generally hydrogen fluoride, a trialkylaluminum, or, more preferably, a metal halide, such as boron or aluminum trifluoride, triiodide, trichloride, or tribromide, tin tetrachloride, zinc dichloride, gallium trichloride, titanium tetrachloride, diethylaluminum chloride, ethylaluminum dichloride, ethoxyaluminum dichloride, diethoxyaluminum chloride, hydroxyaluminum dichloride, dihydroxyaluminum chloride, and other such compounds wherein at least one halogen is attached to a metal atom, any remaining valences of which are usually satisfied by hydroxy, hydrocarbyl, or hydro-carbyloxy groups, generally hydroxy or alkyl or alkoxy groups containing l-lO carbons. The preferred Lewis acids are boron trifluoride and aluminum chloride, especially aluminum chloride. This ingredient of the reaction mixture is ordinarily employed in the amount of 0.5-1.5, preferably l-l.l, mols per mol of aryl ketone, although smaller or larger amounts can be employed if 20 desired.
Alkali metal cyanides utilizable in the process are the lithium, sodium, potassium, rubidium, and cesium cyanldes, with the sodium and potassium cyanides being preferred. To produce good yields of the desired 25 product, it is generally desirable to employ 1-5, pref-erably l-~, mols of alkali metal cyanide per mol of aryl ketone to produce good yields of product.
Çi96 Other ingredients that are suitably included in the reaction mixture are a solvent and a phase transfer catalyst. Solvents that may be employed include all solvents in which the reactants are soluble, such as aliphatic and aromatic hydrocarbons (e.gO, toluene, xylenes, heptanes, and the like), chlorobenzene, nitro-benzene, etc., but the preferred solvent is generally nitrobenzene. Particularly useful phase transfer catalysts are tetraalkylammonium halides (generally such halides containing up to about 50 carbons), preferably bromides and chlorides, such as tetrabutylammonium bromide, tributylmethylammonium chloride, etc. When employed, the catalyst is used in a catalytic amount, e.g., 2-6~ by weight of the aryl ketone; and its use sometimes seems to permit the attainment of higher yields than can be obtained in its absence.
In the practice of the invention, the ingredients of the reaction mixture may be combined in any suitable manner, preferably with the solids in finely-divided form, and heated at a suitable temperature, e.g., 60-120C., preferably about 70-90C., to produce the desired product. Lower temperatures can be used but are less desirable because of their leading to slower re-actions, higher temperatures are apt to be undesirable 25 because of the tendency for by-products to be formed at the higher temperatures. The time required to obtain g~
good yields varies with the temperature but is frequently in the range of 4-10 hours.
It is sometimes preferred to combine the ingredi-ents by prestirring the alkali metal cyanide, the Lewis acid, and a solvent before combining these ingredients with the aryl ketone, and it appears to be desirable to maintain the temperature of these ingredients below 60C., e.g., at 10-50C., conveniently at 20-30C., until the addition of the aryl ketone has been completed It is also sometimes preferred to conduct the cyanation in the presence of a small amount of water and/or concentrated HCl -- additives which appear to effect an activation of one or more of the reactants and increase yields. The particular amount of water and/or HCl employed is an activating amount, i.e., an amount insufficient to hydrolyze the Lewis acid completely, and may be provided simply by the water naturally present in one or more of the aforementioned ingredients of the 20 reaction mixture. ~en it is desired to employ addi-tional water and/or HCl, the added amount is generally in the range of 0.1-1.0 mol per mol of the aryl ketone.
The process is a cyanation reaction which results in the formation of an alpha-arylacrylonitrile. ~hen an aforementioned Ar-C0-R ketone is employed as the starting ~2~ 9~
material, the product corresponds to the formula Ar-C(CN)=R', wherein Ar has the same meaning as given above and R' is the divalent group obtained by removing the removable hydrogen from R.
After completion of the reaction, the product can be recovered by conventional means or, alternatively, can be subjected to further reactions without being isolated when the fu~rther reactions would not be inhibited by impurities in the crude product. It is frequently 10 desirable to subject the alpha-arylacrylonitrile to subsequent reactions. One such reaction is a dehydrogenation of a product such as 6-methoxy-l-cyano-3,4-dihydronaphthalene to a product such as 6-methoxy-l-cyanonaphthalene -- a dehydrogenation that can be 15 accomplished, e.g., by heating the reaction mixture, preferably at reflux temperatures, in the presence of a palladium-on-carbon catalyst or by other techniques known in the art.
The invention is particularly advantageous as a 20 one-step, commercially-acceptable process for preparing alpha-arylacrylonitriles, especially l-cyano-3,4-dihydronaphthalenes, that can then be converted to other products.
EXAMPLE I
A mixture of 1.3 g of dry AlCl3, 0.64 g of dry NaCN, and 87 mg of tetrabutylammonium bromide (TBAB) in 8.7 ml of dry nitrobenzene (NB) was stirred for two hours ~25i5~
under a nitr~gen atmosphere. m en 1.53 g of 6-methoxy-tetralone (6-MT) were added to provide a reaction mixture containin~ the 6-MT, NaCN, and AlC13 in a mol ratio of 1/1.5/1.1 and containing 5.6% of TBAB, based on the weiyht of 6-MT. The reaction mixture was stirred at 90C. for 10 hours to form 6-methoxy-1-cyano-3,4-dihydro-naphthalene (6- MCDN). After workup the VPC ratio of 6-MT/6-MCDN was determined to be 8/92. The process resulted in an 85% isolated yield of 6- rlCDN.
EXAMPLE II
Example I was essentially repeated except that the AlC13/NaCN/TBAB/NB mixture was not subjected to the two hour stirrin~ period prior to the addition of the 6-MT.
After workup the VPC ratio of 6-MT/6-MCDN was determined to be 41/59.
EXAMPLE III
Example I was essentially repeated except that the 6-MT was replaced with 4-methoxyphenyl 3-chloropropyl ketone and the amount of NaCN was reduced to only 1.3 20 molar proportions. VPC analysis showed a 70% conversion of the ketone to alpha-(4-methoxyphenyl)-beta-(2-chloro-ethyl)acrylonitrile.
EXAMPLE IV
A mixture of 1.56 g of boron trifluoride etherate 0.98 g of NaCN, and 100 mg of TBAB in 10 ml of NB was stirred for two hours. Then 1.76 g of 6-MT were added to j9~
g provide a reaction mixture containing the 6-MT, NaCN, and boron trifluoride in a mol ratio of 1/2/1.1. The mixture was heated at 90C. for two hours and then at 120C. for six hours to form 6-MCDN. Analysis showed the 5 6-MT/6-MCDN ratio to be 5/4.
EXAMPLE V
A solution of 22.7 g of anhydrous AlC13 in 100 ml of NB was cooled to 10C. in an ice bath, after which 6.9 g of liquid HCN were added. The mixture was stirred vigorously and 30 g of 6-MT were added to provide a reaction mixture containing the 6-MT, HCN, and AlC13 in a mol ratio of 1/1.5/1. When the 6-MT had completely dissolved, the mixture was transferred to an autoclave and heated at 70C. Eor ten hours. After cooling, the contents oE the autoclave were removed and treated with 100 ml of dilute HCl and lOO.ml of methylene chlorideO
The mixture was shaken in a separatory funnel and allowed to stand for phase separation. The lower organic layer was removed and concentrated on a rotary evaporator to 20 remove methylene chloride. GC investiyation (internal standard method) of the NB solution showed an ~8% yield o f 6 -MCDN .
EXAMPLE VI
A crude 6-MCDN in NB prepared essentially as in 25 Example I was treated with 5% (based on the weight of the original 6-~) of 5% Pd/C at 150-220C. for 10 hours.
~Z5i5~
The process resulted in the conversion of 97~ of the 6-~CDN to 6-methoxy-1-cyanonaphthalene.
It is obvious that many variations can be made in the products and processes set forth above without : 5 departing from the spirit and scope of this invention.
-This invention relates to alpha-arylacrylonitriles and more particularly to a process for pre~aring them.
It is known that alpha-arylacrylonitriles are use-5 ful as chemical intermediates and that they can beprepared in various ways. For example, Jacobs et al., Journal of Organic Chemistry, 1983, Vol. 48, pp~
5134-5135, teach that 6-methoxy-1-cyano-3,4-dihydro-naphthalene is useful as an intermediate in the synthesis 10 of steroids and that it can be prepared by (1) the addition of diethylaluminum cyanide to 6-methoxytetralone followed by dehydration or (2) the addition of cyano-trimethylsilane to 6-methoxytetralone Eollowed by treatment with phosphoryl chloride in pyridine. As 15 taught by Jacobs et al., the former method of synthe-sizing their alpha-arylacrylonitrile is impractical for large scale operations, and the latter method requires two steps.
An object of this invention is to provide a novel 20 process for preparing alpha-arylacrylonitriles.
Another object is to provide such a process which is suitable for large scale operations and produces the alpha-arylacrylonitriles from aryl ketones in a single step.
~55~9~
These and other objects are attained by reacting an aryl ketone having a removable hydrogen alpha to the carbonyl group with an alkali metal cyanide and a Lewis acid.
Aryl ketones that can be used in the practice of the invention can be any aryl ketones having a removable hydrogen alpha to the carbonyl group. ~owever, they are generally aryl ketones corresponding to the formula Ar-C0-R wherein Ar ls aryl and R is a monovalent ali-phatic, cycloaliphatic, or aromatic group having a removable hydrogen in the alpha-position. In such ketones the Ar group is generally an aryl group contain-ing 6-20 carbons, most commonly a phenyl or naphthyl group which optionally bears one or more inert sub-stituents, i.e., substituents that do not inhibit theactivity of the Lewis acid in removing the removable hydrogen, such as alkyl, alkylthio, alkoxy, halo, nitro, etc. The R group is generally a saturated or unsaturated aliphatic, cycloaliphatic, or aromatic group containing 1-20 carbons, optionally bearing one or more inert substituents and sometimes joined with the Ar group to form a fused ring.
Exemplary of such ketones are phenyl alkyl ketones wherein the alkyl group is methyl, ethyl, propyl, iso-propyl, butyl, isobutyl, t-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, etc.; the corresponding substituted-phenyl alkyl ketones wherein the substituents on the benzene ring may be any of the aforementioned alkyl groups and/or the corresponding alkoxy or alkylthio groups, chloro, bromo, nitro, etc.; the corresponding naphthyl or substituted-naphthyl alkyl ketones; the corresponding aryl substituted-alkyl ketones wherein the substituents on the alkyl group may be any of afore-mentioned inert substituents; the corresponding aryl substituted-or-unsubstituted-cycloalkyl (e.g., cyclo-propyl, cyclobutyl, cyclohexyl, cyclooctyl, etc.)ketones; the corresponding aryl substituted~or-unsubstituted-alkenyl ketones wherein the unsaturation is at least olle carbon removed from the carbon bearing the removable hydrogen, such as ketones in which the alkenyl group is 2-butenyl, 3-hexenyl, 4-hexenyl, 4-octenyl, etc.;
the corresponding aryl substltuted-or-unsubstituted-cycloalkenyl ketones; the corresponding aryl substituted-or-unsubstituted-aromatic ketones wherein said aromatic group is benzyl, phenylethyl, phenylpropyl, etc., tetralone, etc. Among the prefèrred ketones are aceto-phenones, such as acetophenone, 4-chloroacetophenone, 4-isobutylacetophenone, 4-ethoxyacetophenone, etc., and tetralones, such as tetralone, 6-methoxytetralone, 7-bromotetralone, etc.
9~
The Lewis acid utilized in the reaction may be any suitable Lewis acid, generally hydrogen fluoride, a trialkylaluminum, or, more preferably, a metal halide, such as boron or aluminum trifluoride, triiodide, trichloride, or tribromide, tin tetrachloride, zinc dichloride, gallium trichloride, titanium tetrachloride, diethylaluminum chloride, ethylaluminum dichloride, ethoxyaluminum dichloride, diethoxyaluminum chloride, hydroxyaluminum dichloride, dihydroxyaluminum chloride, and other such compounds wherein at least one halogen is attached to a metal atom, any remaining valences of which are usually satisfied by hydroxy, hydrocarbyl, or hydro-carbyloxy groups, generally hydroxy or alkyl or alkoxy groups containing l-lO carbons. The preferred Lewis acids are boron trifluoride and aluminum chloride, especially aluminum chloride. This ingredient of the reaction mixture is ordinarily employed in the amount of 0.5-1.5, preferably l-l.l, mols per mol of aryl ketone, although smaller or larger amounts can be employed if 20 desired.
Alkali metal cyanides utilizable in the process are the lithium, sodium, potassium, rubidium, and cesium cyanldes, with the sodium and potassium cyanides being preferred. To produce good yields of the desired 25 product, it is generally desirable to employ 1-5, pref-erably l-~, mols of alkali metal cyanide per mol of aryl ketone to produce good yields of product.
Çi96 Other ingredients that are suitably included in the reaction mixture are a solvent and a phase transfer catalyst. Solvents that may be employed include all solvents in which the reactants are soluble, such as aliphatic and aromatic hydrocarbons (e.gO, toluene, xylenes, heptanes, and the like), chlorobenzene, nitro-benzene, etc., but the preferred solvent is generally nitrobenzene. Particularly useful phase transfer catalysts are tetraalkylammonium halides (generally such halides containing up to about 50 carbons), preferably bromides and chlorides, such as tetrabutylammonium bromide, tributylmethylammonium chloride, etc. When employed, the catalyst is used in a catalytic amount, e.g., 2-6~ by weight of the aryl ketone; and its use sometimes seems to permit the attainment of higher yields than can be obtained in its absence.
In the practice of the invention, the ingredients of the reaction mixture may be combined in any suitable manner, preferably with the solids in finely-divided form, and heated at a suitable temperature, e.g., 60-120C., preferably about 70-90C., to produce the desired product. Lower temperatures can be used but are less desirable because of their leading to slower re-actions, higher temperatures are apt to be undesirable 25 because of the tendency for by-products to be formed at the higher temperatures. The time required to obtain g~
good yields varies with the temperature but is frequently in the range of 4-10 hours.
It is sometimes preferred to combine the ingredi-ents by prestirring the alkali metal cyanide, the Lewis acid, and a solvent before combining these ingredients with the aryl ketone, and it appears to be desirable to maintain the temperature of these ingredients below 60C., e.g., at 10-50C., conveniently at 20-30C., until the addition of the aryl ketone has been completed It is also sometimes preferred to conduct the cyanation in the presence of a small amount of water and/or concentrated HCl -- additives which appear to effect an activation of one or more of the reactants and increase yields. The particular amount of water and/or HCl employed is an activating amount, i.e., an amount insufficient to hydrolyze the Lewis acid completely, and may be provided simply by the water naturally present in one or more of the aforementioned ingredients of the 20 reaction mixture. ~en it is desired to employ addi-tional water and/or HCl, the added amount is generally in the range of 0.1-1.0 mol per mol of the aryl ketone.
The process is a cyanation reaction which results in the formation of an alpha-arylacrylonitrile. ~hen an aforementioned Ar-C0-R ketone is employed as the starting ~2~ 9~
material, the product corresponds to the formula Ar-C(CN)=R', wherein Ar has the same meaning as given above and R' is the divalent group obtained by removing the removable hydrogen from R.
After completion of the reaction, the product can be recovered by conventional means or, alternatively, can be subjected to further reactions without being isolated when the fu~rther reactions would not be inhibited by impurities in the crude product. It is frequently 10 desirable to subject the alpha-arylacrylonitrile to subsequent reactions. One such reaction is a dehydrogenation of a product such as 6-methoxy-l-cyano-3,4-dihydronaphthalene to a product such as 6-methoxy-l-cyanonaphthalene -- a dehydrogenation that can be 15 accomplished, e.g., by heating the reaction mixture, preferably at reflux temperatures, in the presence of a palladium-on-carbon catalyst or by other techniques known in the art.
The invention is particularly advantageous as a 20 one-step, commercially-acceptable process for preparing alpha-arylacrylonitriles, especially l-cyano-3,4-dihydronaphthalenes, that can then be converted to other products.
EXAMPLE I
A mixture of 1.3 g of dry AlCl3, 0.64 g of dry NaCN, and 87 mg of tetrabutylammonium bromide (TBAB) in 8.7 ml of dry nitrobenzene (NB) was stirred for two hours ~25i5~
under a nitr~gen atmosphere. m en 1.53 g of 6-methoxy-tetralone (6-MT) were added to provide a reaction mixture containin~ the 6-MT, NaCN, and AlC13 in a mol ratio of 1/1.5/1.1 and containing 5.6% of TBAB, based on the weiyht of 6-MT. The reaction mixture was stirred at 90C. for 10 hours to form 6-methoxy-1-cyano-3,4-dihydro-naphthalene (6- MCDN). After workup the VPC ratio of 6-MT/6-MCDN was determined to be 8/92. The process resulted in an 85% isolated yield of 6- rlCDN.
EXAMPLE II
Example I was essentially repeated except that the AlC13/NaCN/TBAB/NB mixture was not subjected to the two hour stirrin~ period prior to the addition of the 6-MT.
After workup the VPC ratio of 6-MT/6-MCDN was determined to be 41/59.
EXAMPLE III
Example I was essentially repeated except that the 6-MT was replaced with 4-methoxyphenyl 3-chloropropyl ketone and the amount of NaCN was reduced to only 1.3 20 molar proportions. VPC analysis showed a 70% conversion of the ketone to alpha-(4-methoxyphenyl)-beta-(2-chloro-ethyl)acrylonitrile.
EXAMPLE IV
A mixture of 1.56 g of boron trifluoride etherate 0.98 g of NaCN, and 100 mg of TBAB in 10 ml of NB was stirred for two hours. Then 1.76 g of 6-MT were added to j9~
g provide a reaction mixture containing the 6-MT, NaCN, and boron trifluoride in a mol ratio of 1/2/1.1. The mixture was heated at 90C. for two hours and then at 120C. for six hours to form 6-MCDN. Analysis showed the 5 6-MT/6-MCDN ratio to be 5/4.
EXAMPLE V
A solution of 22.7 g of anhydrous AlC13 in 100 ml of NB was cooled to 10C. in an ice bath, after which 6.9 g of liquid HCN were added. The mixture was stirred vigorously and 30 g of 6-MT were added to provide a reaction mixture containing the 6-MT, HCN, and AlC13 in a mol ratio of 1/1.5/1. When the 6-MT had completely dissolved, the mixture was transferred to an autoclave and heated at 70C. Eor ten hours. After cooling, the contents oE the autoclave were removed and treated with 100 ml of dilute HCl and lOO.ml of methylene chlorideO
The mixture was shaken in a separatory funnel and allowed to stand for phase separation. The lower organic layer was removed and concentrated on a rotary evaporator to 20 remove methylene chloride. GC investiyation (internal standard method) of the NB solution showed an ~8% yield o f 6 -MCDN .
EXAMPLE VI
A crude 6-MCDN in NB prepared essentially as in 25 Example I was treated with 5% (based on the weight of the original 6-~) of 5% Pd/C at 150-220C. for 10 hours.
~Z5i5~
The process resulted in the conversion of 97~ of the 6-~CDN to 6-methoxy-1-cyanonaphthalene.
It is obvious that many variations can be made in the products and processes set forth above without : 5 departing from the spirit and scope of this invention.
Claims (17)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOW
1. A process which comprises reacting an aryl ketone having a removable hydrogen alpha to the carbonyl group with an alkali metal cyanide and a Lewis acid.
2. The process of claim 1 wherein an aryl ketone corresponding to the formula Ar-CO-R is reacted with the alkali metal cyanide and Lewis acid so as to form an alpha-arylacrylonitrile corresponding to the formula Ar-C(CN)=R', in which formulas Ar is aryl, R is a monovalent aliphatic, cycloaliphatic, or aromatic group having a removable hydrogen in the alpha-position, and R' is the divalent group obtained by removing the removable hydrogen from R.
3. The process of claim 2 wherein the aryl ketone is an acetophenone.
4. The process of claim 3 wherein the aceto-phenone is 4-isobutylacetophenone.
5. The process of claim 2 wherein the aryl ketone is a tetralone.
6. The process of claim 5 wherein the tetralone is 6-methoxytetralone.
7. The process of claim 1 wherein the alkali metal cyanide is sodium cyanide.
8. The process of claim 1 wherein the alkali metal cyanide is potassium cyanide.
9. The process of claim 1 wherein the Lewis acid is aluminum chloride.
10. The process of claim 1 wherein the reaction is conducted in the presence of a catalytic amount of a phase transfer catalyst.
11. The process of claim 10 wherein the catalyst is a tetraalkylammonium halide.
12. The process of claim 11 wherein the tetraalkylammonium halide is tetrabutylammonium bromide.
13. The process of claim 1 wherein the reaction i 5 conducted in a solvent.
14. The process of claim 13 wherein the solvent is nitrobenzene.
15. The process of claim 1 wherein the reaction is conducted at a temperature of 60-120°C.
16. A process which comprises reacting a tetra-lone having a removable hydrogen alpha to the carbonyl group with an alkali metal cyanide and aluminum chloride in the presence of a catalytic amount of a tetraalkyl-ammonium halide at a temperature of 60-120°C. so as to form a 1-cyano-3,4-dihydronaphthalene.
17. The process of claim 16 wherein the tetralone is 6-methoxyteralone and the product is 6-methoxy-1-cyano-3,4-dihydro-naphthalene.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US676,479 | 1984-11-29 | ||
| US06/676,479 US4536343A (en) | 1984-11-29 | 1984-11-29 | Process for preparing alpha-arylacrylonitriles |
| US06/735,148 US4590012A (en) | 1985-05-17 | 1985-05-17 | Process for preparing alpha-arylacrylonitriles |
| US735,148 | 1985-05-17 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1255696A true CA1255696A (en) | 1989-06-13 |
Family
ID=27101563
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000493065A Expired CA1255696A (en) | 1984-11-29 | 1985-10-16 | PROCESS FOR PREPARING .alpha.-ARYLACRYLONITRILES |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1255696A (en) |
-
1985
- 1985-10-16 CA CA000493065A patent/CA1255696A/en not_active Expired
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