Patent GB-834562-A (GB)
Title: Reactions involving grignard reagents
IPC: C07B49/00
Filed: 1956-05-03
Abstract: Organomagnesium chloride complexes are used to prepare organic hydroxy compounds, thioketones, thioaldehydes, mercaptans, hydroselenides, hydrotellurides, sulphinic acids, ketones, aldehydes, sulphoxides, sulphones. sulphides and disulphides by reacting with oxygen, sulphur, selenium, tellurium, sulphur dioxide, thionyl chloride, sulphuryl chloride, a sulphonyl chloride, sulphur monochloride or sulphur dichloride, an organomagnesium chloride complex of formula R(MgCl)x.nQ and hydrolysing the reaction product, e.g. by addition of water or dilute acid, R being an aryl, vinylic, or heterocyclic radical which may be substituted or unsubstituted, which when heterocyclic exhibits aromatic or pseudoaromatic properties (i.e. undergoes aromatic substitution reactions) and includes in its heterocyclic ring oxygen, sulphur or tertiary nitrogen, and is bound to magnesium through a carbon atom of an aromatic or pseudoaromatic ring, R containing no functional group which is reactive under the conditions for the formation of the complex, Q being a substituted or unsubstituted heterocyclic ether having 5 or 6 atoms in the ring, of which atoms only one is oxygen, the other ring atoms being carbon with the exception that a substituted nitrogen atom may replace carbon in 4-position when the ring has 6 atoms, the ring containing not more than one double bond and at least one carbon atom in the ring adjacent the oxygen atom being free of any substituents, said ether containing no substituent which reacts with the organomagnesium chloride complex or with other components or products of the reaction mixture, x being 1 or 2, and n being a small whole number from 1 to 3.  In preparing vinylic mercaptides or vinylic compounds of selenium or tellurium, the hydrolysis step may be omitted and a metal salt included in the reaction mixture. The radical R may have the formula <FORM:0834562/IV (b)/1> Ra, Bb, Rc, Rd and Re being th same or different and representing hydrogen, fluorine, chlorine, or an alkyl, aryl, aralkyl heterocyclic, alkoxy, allyloxy, aryloxy, or dialkylamino group, or the formula <FORM:0834562/IV (b)/2> wherein R1, R11 and R111 are the same or different and represent an hydrogen atom or a substituted or unsubstituted aliphatic or aromatic hydrocarbon group, wherein R1 may be cyclized with R11 or R111, and R111 may be chlorine, or when x is 2, the formula <FORM:0834562/IV (b)/3> R1 and R11 being as above. The reaction may be carried out in an inert hydrocarbon solvent or in compound Q as reaction medium, and examples of Q specified are tetrahydrofuran, tetrahydropyran, 2 - methyltetrahydrofuran, 2 - ethoxytetrahydrofuran, tetrahydrofurfuryl ethyl ether, dihydropyran, and N-methylmorpholine.  In examples, (1) phenylmagnesium chloride tetrahydrofuran complex in excess tetrahydrofuran is heated with sulphur and then dilute acid added to the mixture giving thiophenol; (2) air is bubbled through a solution of phenylmagnesium chloride-tetrahydropyran complex in tetrahydropyran followed by addition of water to give phenol; (3) sulphur dioxide is bubbled through a solution of phenyl magnesium chloride complex in methyltetrahydrofuran followed by addition of water to give benzene sulphuric acid.  Further examples repeat Example 1 above, but replacing the sulphur by (4) thionyl chloride to give diphenylsulphoxide; (5) sulphuryl chloride to give diphenyl sulphone; (6) benzene sulphonyl chloride to give diphenyl sulphone; (7) sulphur dichloride to give diphenyl sulphide; (8) sulphur monochloride to give diphenyl disulphide.  In similar examples, vinylmagnesium chloride reacts with (9) sulphur to give thioacetaldehyde; (10) oxygen to give acetaldehyde; (11) thionyl chloride to give divinyl sulphoxide; (12) p-toluene sulphonyl chloride to give vinyl p-tolyl sulphone; (13) sulphur dichloride to give divinyl sulphide; (14) sulphur monochloride to give divinyl disulphide.  Products of further similar examples are di-p-chlorphenyl sulphide, di-p-chlorphenyl sulphone, phenyl-p-chlorphenyl sulphone, o-thiocresol, di-m-tolyl sulphide, di-p-tolyl sulphide, hydroquinone monomethyl ether, di-p-anisyl sulphone, p - ethoxythiophenol, dichlorthiophenol, trichlorphenol, di - tetrachlorphenyl sulphide, pentachlorphenyl-p-tolyl sulphone, 2,6 - dimethylphenol -, 2,6 - dimethylphenylsulphinic acid, p - phenylphenol, mercaptotrichlorobiphenyl, nonachlorbiphenylsulphinic acid, a  - thionaphthol, b  - naphthol, o - trifluoromethylphenol, bis - p - dimethylaminophenyl sulphone, bis - dimethylaminophenyl sulphide, p - dimethylaminobenzenesulphinic acid, p - diethylaminobenzenesulphinic acid, p - diethylaminothiophenol, chlorothiocresol, bis - chlorotolyl sulphone, bis - chloroanisyl sulphide, bis-chlorphenetyl sulphide, ethyl tetrachlorthiophenol, a  - thienylsulphinic acid, bis - a  - thienyl sulphone, a  - thienyl - p - tolyl sulphone, bis - a  - thienyl sulphide, 2 - pyridone, bis - furyl sulphide, bis - 5 - chloro - 2 - thienyl sulphone, bix - 5 - chloro - 2 - thienyl sulphide, m - fluorothiophenol, bis - m - fluorophenyl sulphide, difluorothiophenol, trifluorothiophenol, bis - pentafluorophenyl sulphide, 2 - hydroxybenzothiazole, 2 - mercaptobenzothiazole, bis - 2 - benzothiazolyl sulphide and disulphide, 2 - mercaptobenzoxazole, 2 - methyl - 5 - hydroxybenzothiazole, bis - 2 - quinolyl sulphide, 6 - hydroxyquinoline, 8 - hydroxyquinoline, 4,5,6 - trichlorpyrimidylsulphinic acid, bis - 1 - cyclohexenyl sulphone, bis - 4 - methyl - 1 - penten - 2 - yl sulphide, bis - 2 - propen - 2 - yl sulphone, phenyl - 1 - propen - 1 - yl sulphone, bis - 2 - buten - 2 - yl disulphide, phenyl - 1 - buten - 1 - yl sulphone, bis - N - methylpyrryl sulphide, 4 - vinylphenol, thymol, phenyl hydroselenide, phenyl hydrotelluride.