Patent GB-802517-A (GB)
Title: Reactions of organo magnesium chloride reagents
IPC: C07D215/04
Filed: 1956-05-03
Abstract: Hydrocarbylsilylaryl magnesium chloride complexes are made by reacting a hydrocarbylsilylaryl chloride with magnesium in the presence of a compound Q containing a 5 or 6-membered heterocyclic ring with only one oxygen atom.  Such complexes may have the formul : MgCl.R.Si.R13.nQ, or (MgCl.R)2.SiR12.nQ, where R1 is a hydrocarbon group, R is aryl, e.g. phenyl or diphenyl, and may contain unreactive substituents such as chlorine, and n is 1 to 3. The complexes are reacted with aldehydes or ketones and the products hydrolysed to yield substituted alcohols which may be dehydrated to olefinic compounds.  In an Example (66), p-trimethylsilylphenylmagnesium chloride-tetrahydrofuran complex is reacted with acetaldehyde in tetrahydrofuran and the product treated with dilute H2SO4 to give a ,p-trimethylsilylphenylethanol which by refluxing in benzene yields p - trimethylsilylstyrene.  Vinyl magnesium chloride complexes CH2=CH.MgCl.nQ may be reacted to yield polymeric vinyl compounds. Thus, in Examples (8) and (9), Q is tetrahydrofuran which is used as the medium for reacting the complex with benzalacetone or dibenzalacetone, followed by hydrolysis giving a polymer of methyl-vinyl-styryl carbinol or distyryl-vinyl-carbinol.ALSO:Substituted alcohols or aldehydes or ketones are prepared by reacting with a saturated or unsaturated aldehyde or ketone an organo magnesium chloride complex of formula R(MgCl)x.nQ and hydrolysing the reaction product to yield a substituted alcohol or, where the aldehyde or ketone is of the a ,b -unsaturated type, another aldehyde or ketone, R being a substituted or unsubstituted aryl or vinylic group or heterocyclic radical exhibiting aromatic or pseudoaromatic characteristics and including in the heterocyclic ring an oxygen, sulphur or tertiary nitrogen atom, and which is bound to magnesium through a carbon of an aromatic or heterocyclic ring, R containing no functional group which is reactive under the conditions for formation of the complex, n being from 1 to 3, x an integer, and Q a substituted or unsubstituted cyclic ether having 5 or 6 atoms in the ring, of which only one atom is oxygen, the others being carbon except that a substituted nitrogen may replace the carbon in the 4-position when the ring has six atoms, the ring containing not more than one double bond and at least one carbon adjacent to the oxygen being free of substituents, said ether being free of any substituent which is reactive with organo magnesium chlorides or any other components or products of the process.  Such organo magnesium chloride complexes are described in Specifications 776,993, 777,158 and 779,100.  Complexes containing also silicon or tin are prepared by reacting hydrocarbyl silyl (or stannyl) aryl chlorides with magnesium in presence of compound Q.  Aryl may, e.g., be phenyl or diphenyl. The reaction with the aldehyde or ketone may be effected in a compound Q or inert hydrocarbon as reaction medium, preferably between room temperature and the reflux temperature. Water or dilute acid is added to the product and the substituted alcohol recovered, as by distillation.  Dehydration to olefins or olefinic compounds may be effected.  Equations illustrate the reaction of numerous types of complex, the organic radical of which may have various substituents, with many aldehydes and ketones including quinone which yields vinyl derivatives of quinol with vinyl magnesium chloride complex.  Where x is greater than 1, e.g. 2 to 6 or more, di- or poly-hydric alcohols of aliphatic, aromatic or heterocyclic nature are obtained.  In the following examples, Q is tetrahydrofuran unless specified: (1) R is vinyl and the complex is added to trioxymethylene in Q in absence of air at about 40 DEG  C., allyl alcohol being recovered; (2) R is vinyl and the aldehyde acetaldehyde, methyl vinyl carbinol being obtained; (3) butyraldehyde yields propyl vinyl carbinol; (4) benzaldehyde gives phenyl vinyl carbinol; (5) Q is tetrahydropyran, R is vinyl, and with acetone, 3 - methyl - 1 - buten - 3 - ol is produced which on heating with aniline hydrobromide gives isoprene; (6) R is vinyl and 1-vinylcyclohexanol-1 is prepared from cyclohexanone; (7) acetophenone yields methyl-vinyl-phenyl-carbinol; (8) benzalacetone gives a resinous polymer of methyl-vinyl-styryl-carbinol; (9) dibenzalacetone gives a polymer of distyryl - vinyl - carbinol; (10) R is phenyl and with trioxymethylene benzyl alcohol is obtained; (11) Q is methyl-tetrahydrofuran, R is phenyl and reaction with acetone gives 2-phenyl-2-propanol which on dehydration with acetic acid and a crystal of iodine gives 2-phenyl-propylene; (12) R is p-chlorphenyl and acetaldehyde yields a -p-chlorphenylethanol which on dehydration over alumina gives p-chlorstyrene; (13) crotonaldehyde yields 3-p-chlorphenyl-1-butyral; (14) cyclohexanone gives 1-p - chlorophenyl - 1 - cyclohexanol; (15) R is 3,4-dichlorphenyl and benzaldehyde yields 3,4-dichlorbenzhydrol; (16) cyclohexanone yields 1 - (3,4 - dichlorphenyl) - 1 - cyclohexanol; (17) R is 2,4,5-trichlorphenyl and benzaldehyde gives 2,4,5-trichlorphenyl-benzhydrol; (18) acetone gives 2-(2,4,5-trichlorphenyl)-2-propanol which is dehydrated to the trichlorphenyl-propylene; (19) R is 2,3,4,5,6-pentachlorphenyl, butyraldehyde giving 1-(2,3,4,5,6-pentachlorphenyl)-1-butanol; (20) cyclohexanone gives the pentachlorphenyl-cyclohexanol; (21) benzaldehyde gives the pentachlorbenzhydrol; (22) acetophenone gives a -phenyl-a -(2,3,4,5,6-pentachlorphenyl)-ethanol; (23) R is 2(4)-chlor-4(2)-tolyl and acetaldehyde yields a -[2(4)-chlor-4(2)-tolyl]-ethanol; (24) benzalacetone yields 4 - phenyl - 4 - [2(4) - chlor - 4(2) - tolyl] - 2 - butanone and a -styryl-a -[2(4)-chlor-4(2)-tolyl]-ethanol; (25) R is o-tolyl and butyraldehyde gives 1-o-tolyl-1-butanol; (26) 1-m-tolyl-1-butanol is made similarly; (27) the p-tolyl compound is made similarly and dehydrated to 1-p-tolyl-1-butene; (28) R is o-tolyl and acetophenone gives 1-phenyl-1-o-tolylethanol; (29) the m-tolyl derivative is made similarly and dehydrated to a -tolylstyrene; (30) the p-tolyl derivative is prepared; (31) R is 2-ethoxy-phenyl, benzaldehyde giving a  - (2 - ethoxy-phenyl)-benzyl alcohol; (32) R is 2-thenyl, trioxymethylene giving 2-thenyl alcohol; (33) cyclohexanone gives 1-(a -thienyl)-1-cyclohexanol; (34) R is a -pyridyl, trioxymethylene giving a -pyridylcarbinol; (35) cyclohexanone gives a -pyridyl-1-cyclohexanol; (36) R is 2-quinolyl and acetaldehyde gives 1-(2-quinolyl)-ethanol which is dehydrated to 2-vinylquinoline; (37), (38) 6- and 8-quinolyl-ethanols are made similarly; (39) R is 2-quinolyl, acetophenone giving 1 - phenyl - 1 - (2 - quinolyl) - ethanol; (40), (41) the 6- and 8-quinolyl-ethanols are similarly prepared; (42) R is 2-benzoxazolyl, butyralde hyde giving 1-(2-benzoxazolyl)-1-butanol; (43) the 2-benzothiazolyl compound is similarly made; (44) R is 2-benzoxazolyl, benzalacetone yielding a  - styryl - a  - (2 - benzoxazolyl) - ethanol and 4-phenyl-4-(2-benzoxazolyl)-2-butanone; (45) the corresponding 2-benzothiazolyl compounds are formed when R is 2-benzothiazolyl; (46) R is 2-methylbenzothiazol-5-yl, butyraldehyde giving 1-(2-methyl-5-benzothiazolyl)-1-butanol which is dehydrated to the 1-butene; (47) benzalacetone yields products analogous with those of (44); (48), (49) R is 6-chlor-2-methoxy-acrid-4-yl, benzaldehyde yielding a  - (6 - chlor - 2 - methoxy - 4 - acridyl) - benzyl alcohol, and acetone 2-(6-chlor-2-methoxy - 4 - acridyl) - 2 - propanol; (50), (51) R is 4(6) - chlor - 6(4) - pyrimidyl, benzaldehyde giving 4(6) - chlor - 6(4) - pyrimidylphenyl carbinol and acetone 2-[4(6)-chlor-6(4)-pyrimidyl]-2-propanol, the latter being dehydrated to 4(6) - chlor - 6(4) - (2 - propenyl) - pyrimidine; (52), (53) R is a -furyl, benzaldehyde giving a -furylphenyl carbinol and cyclohexanone 1-a -furyl-1-cyclohexanol which loses water to give 1-a -furyl-1-cyclohexene; (54) 2,5-thiophene dimagnesium chloride complex with acetaldehyde gives 2,5 - bis - (1 - hydroxyethyl) - thiophene, dehydrated to 2,5-divinylthiophene, and with acetone gives 2,5-bis - (2 - hydroxypropyl) - thiophene, dehydrated to 2,5 - bis - (2 - propenyl) - thiophene; (56), (57) R is 2-chlor-5-thienyl, crotonaldehyde giving 3-(2-chlor-5-thienyl)-1-butyral and acetophenone a -phenyl-a -(2-chlor5-thienyl)-ethanol which is dehydrated to 2-chlor - 5 - (a - phenylvinyl) - thiophene; (58) R is 1 - chlor - 1 - propenyl, butyraldehyde giving 3 - chlor - 2 - hepten - 4 - ol which is dehydrated to 3-chlor-2,4-heptadiene; (59) benzaldehyde gives 1-phenyl-2-chlorcrotonyl alcohol; (60) cyclohexanone gives 1 - (1 - chlor - 1 - propen - 1-yl)-1-cyclohexanol, dehydrated to the cyclohexene; (61) acetophenone gives 3-chlor-4-phenyl-2-penten-4-ol; (62) R is p-dimethyl-aminophenyl, and acetaldehyde yields a -p-dimethylaminophenylethanol; (63) R is pentafluorphenyl, and acetaldehyde gives a -pentafluorphenyl-ethanol; (64) p-fluorphenylmagnesium chloride gives a -fluorphenylethanol; (65) o-trifluormethylphenylmagnesium chloride yields a  - o - trifluormethylphenylethanol; (66) p - trimethylsilylphenylmagnesium chloride yields a  - p - trimethylsilylphenylethanol which is dehydrated to p-trimethylsilyl-styrene; (67) p - tributylstannylphenylmagnesium chloride yields a  - p - tri - n - butylstannylphenylethanol; (68) R is vinyl, and 6-methyl-5-hepten-2-one yields 3,7-dimethyl-1,6-octadienol-3; (69) b - ionone yields 5 - (2,2,6 - trimethyl - 6 - cyclohexen-1-yl)-3-methyl-1,4-pentadien-3-ol.