O-Bromoanisole

The procedure above is a modification of the method of Ullmann and Stein for the same compound. Sartoretto and Sowa used the same general method. The need for a catalyst can be avoided by heating a mixture of guaiacol potassium, guaiacol, and chlorobenzene at 200° under pressure. Ullmann and Stein have prepared the compound by using phenol, o-bromoanisole. 

It had been known many years earlier that aromatic nucleophilic substitution occasionally results in substitution at a different position. This is called cine substitution and can be illustrated by the conversion of o-bromoanisole to m-aminoanisole. In this particular case, only the meta isomer is formed. The... 

This procedure may be employed for m-chlorobromobenzene, b.p. 191-194° from tn chloroaniline m-dibromobenzene, b.p. 215-217°, from m-bromoaniline and o-bromoanisole, b.p. 114 116°/29 mm. from o anisidine (the sulphuric acid washing is omitt in the last example). 

A. 4-Dimethylamino-2 -methoxybmzhydrol. An ethereal solution of o-methoxyphenylmagnesium bromide is prepared in the usual manner2 with 250 ml. of anhydrous ether, 14.5 g. (0.60 g. atom) of magnesium, and 100 g. (0.53 mole) of o-bromoanisole (Note 1). A solution of 60 g. (0.40 mole) of />-dimethylamino-benzaldehyde (Note 2) in 200 ml. of anhydrous benzene is added dropwise to the Grignard reagent (Note 3). After the addition is completed, the reaction mixture is stirred for 10 hours at room... 

If this step is omitted, the o-anisaldehyde obtained after hydrolysis of the oxazolidine is contaminated with 5-10% o-bromoanisole. 

Methyl o-methoxyphenyl telluride (typical procedure). To a frozen solution of MeTeLi (50 mmol) is added o-bromoanisole (9.3 g, 50 mmol). The mixture is allowed to warm at room temperature, stirred for 1.5 h and then quenched with deoxygenated H2O (100 mL). The organic product is extracted with ether (3X50 mL), the organic extracts dried (MgS04) for 16 h and evaporated, and the residue is distilled under vacuum, giving the telluride as a pale yellow oil (9.3 g (74%)). 

Problem 11.28 How do the following observations support the benzyne mechanism (a) Compounds lacking ortho H s, such as 2,6-dimethylchlorobenzene, do not react, (t) 2,6-Dideuterobromobenzene reacts more slowly than bromobenzene. (c) o-Bromoanisole, o-CHjOC H Br, reacts with NaNH /NH, to form m-CHjOC H.NHj. 

Phenyl n-propyl et.her. Phenyl n-butyl ether o-Cresyl methyl ether (1) m-Cresyl methyl ether. p-Cresyl methyl ether. o-Cresyl ethyl ether m-Cresyl ethyl ether p-Cresyl ethyl ether Benzyl methyl ether Benzyl ethyl ether Methyl a-naphthyl ether Methyl p-naphthyl ether Ethyl a-naphthyl ether Ethyl p-naphthyl ether Benzyl a-naphthyl ether Benzyl P-naphthyl ether o-Methoxydiphenyl p-Methoxydiphenyl. o-Chloroanisole. m-Chloroanisole. p-Chloroanisolc o-Bromoanisole m-Bromoanisole. p-Bromoanisole. o-Iodoanisole m-Iodoanisole p-Iodoanisole o-Nitroanisole... 

Bromo-4-acetaminotoluene, 593, 605 p-Bromoacetanilide, 577, 580 p - Bromoace tophenone. 726, 732 m-Bromo-p-acetotoluidido, 593, 605 3-Bromo-4-aminotoluene, 593, 605 hydrochloride, 605 p-Bromoanilides, 361 p-Bromoaniline, 577, 580 o-Bromoanisole, 404 p-Bromobenzaldehyde, 689, 694, 696 diacetate, 696... 

A solution of Grignard reactive (prepared from 247 g of o-bromoanisole and 31.6 g of magnesium in 1500 ml of ether) is added dropwise to a solution of 91 g of diphenyl pyruvic acid in ether. The mixture is refluxed for 2 hours. After cooling to the reaction mixture is added 5% hydrochloric acid and the product is extracted with 5% solution of sodium hydroxide. a-(o-Anisyl)-p,15-diphenyl lactic acid is precipitated by addition of concentrated hydrochloric acid yield 62 g, melting point 194-195°C. 

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