0-Anisidine, diazotization

Guaiacols. Cresote, obtained from the pyrolysis of beechwood, and its active principles guaiacol [90-05-1] (1) and cresol [93-51-6] (2) have long been used ia expectorant mixtures. The compounds are usually classed as direct-acting or stimulant expectorants, but their mechanisms of action have not been well studied. Cresol is obtained by the Clemmensen reduction of vanillin (3), whereas guaiacol can be prepared by a number of methods including the mercuric oxide oxidation of lignin (qv) (4), the ziac chloride reduction of acetovanillone (5), and the diazotization and hydrolysis of o-anisidine (6). 

Reaction of chlorosulfonic acid with mono- [141] or disazo dyes [142] yields sulfonyl chlorides, which can then be transformed into cationically substituted sulfonamides by reaction with dialkylaminoalkylamines. The coupling product of diazotized 2-anisidine with 2-hydroxynaphthoic acid arylide upon such treatment dyes paper red, and the azo dye from tetrazotized dianisidine and l-phenyl-3-methyl-5 -pyrazolone gives yellowish orange shades. 

The 2-aryl-l,2,3-triazolo[4,5-d]pyrimidines 68 were prepared by coupling diazotized p-anisidine with 4-amino-2-(dimethylamino)-6-methoxypyrimi-dine (66) to give the azo intermediate 67, which upon heating in pyridine containing CuSC>4 5H20 gave 68 (80GEP3001424) (Scheme 12). 

Dinitroozoonisole or 4,4 -AzobiS (3-nitroonisolo), CH,-0-C H,(N02)>N N-(N0,)C H, 0 CH mw 332.27, N 16.86% bright orn prisms (from nitiobenzene), mp 259°. It was prepd by diazotizing 3-nitro p-anisidine, 0,N(CH,0)C4H,NHi, and treating the diazonium soln with aq CuOH. This action yielded 2,2 —dinitro p,p -bisanisole and a considerable amt of the azobisnitro-anisole obtained from the acetic acid insol resid ie. See also Ref 2 for prepn by oxidation of 4-methoxy2>nitroaniline Refs DW.CLothrop, JACS 64, 1700(1942)... 

Fierz-David and Ziegler (301) first applied this method to azo compounds. Ethyl acetoacetate and various aromatic amines (aniline, o- and p-toluidines, m-xylidine, o-anisidine, and chloroanilines) were convereted to acetoacetanilides and then coupled with diazotized sulfanilic acid. The azo dyes (38) were reduced with stannous chloride in hydrochloric acid to the corresponding aminoaceto-acetanilides (39), which in alkali formed the dihydropyrazines (40). Catalytic reduction of o-hydroxyphenylglyoxal phenylhydrazone in acetic acid over palladium has been shown also to give 2,5-bis(o-hydroxyphenyl)pyrazine (302). Reduction of chemical means has been shown to give... 

Derivation (1) By extracting beechwood creosote with alcoholic potash, washing with ether, crystallizing the potash compound from alcohol, and decomposing it with dilute sulfuric acid. (2) Also from o-anisidine by diazotization and subsequent action of dilute sulfuric acid. 

Mallinckrodt has reported a similar process for manufacture of OMC that involves the diazotization of p-anisidine in aqueous iodide to produce p-iodoanisole which is then reacted with OA in the presence of trialkylamine (as a base) and Pd/C, without solvent, to yield OMC the process requires the recovery of iodide and the R3N with alkali hydroxide [26]. 

A solution of copper bromide in hydrobromic acid suitable for use in the preparation of 0-bromoanisole (from about 4 moles of diazotized o-anisidine) is obtained very simply by treating a solution of CuS04 5H20 (260 g) and NaBr (625 g) in water (500 ml) with concentrated H2S04 (120 g) and boiling the mixture for 4 h with copper powder or turnings... 

OTHER COMMENTS o-anisidine is used as an intermediate in the manufacture of azo dyes and in the production of Solvent Red 1 used to prepare guaiacol via diazotization and hydrolysis p-anisidine is used in the manufacture of azo dyes and as a chemical intermediate for Vat Red 29, Disperse Orange 15, and Azoic Coupling Component 13. 

Preparations from the stem bark of the Indian curry-leaf tree, Murraya koenigii Spreng. (Rutaceae) are used externally to cure skin eruptions. Extraction of the stem bark yielded three compounds, two of which appear to be carbazole derivatives, while the third is as yet of unknown character. Murraj anine, C14H11NO2 (mp 168°) was shown by examination of its spectra and reactions, and by conversion into 3-methylcarbazole and 1-methoxycarbazole, to be either 6-formyl-l-methoxycarbazole or 3-formyl-1-methoxycarbazole (IV), probably the latter (19). This conclusion has now" been confirmed by an unambiguous synthesis (30). 4-Bromo-o-anisidine was converted bj diazotization followed by reduction with stannous chloride into 4-bromo-2-methoxy-])henylh drazine (V). Condensation of V w ith cyclohexanone and cj cli-... 

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