Gomberg

This is sometimes called the Gomberg or the Gomberg - Hey reaction. 

Gabriel synthesis Gattermaim aldehyde reaction Gattermann reaction Gattermann-Kocll reaction Gomberg-Hey reaction Grignard reaction... 

Von Baeyer (Nobel Prize, 1905) should be credited for having recognized in 1902 the saltlike character of the compounds formed. He then suggested a correlation between the appearance of color and salt formation—the so-called halochromy. Gomberg (who had just shortly before discovered the related stable triphenylmethyl radical), as well as Walden, contributed to the evolving understanding of the structure of related cationic dyes such as malachite green. 

G. Gomberg reaction. TABLE m-36. EXPERIMENTAL ISOMER DISTRIBUTION. RELATIVE REAC-... 

Hypochlorination. Both ethylene chloiohydiin and propylene chloiohydiin were prepared by Wurtz (12) as a result of the reactions of HCl [7647-01-0] with the corresponding glycol under pressure. Shordy afterward, Carius (13) synthesized ethylene chlorohydria by reaction of hypochlorous acid with ethylene [74-85-1]. The first detailed iavestigation of the formation of ethylene chlorohydria by the reaction of ethylene with hypochlorous acid [7790-92-3] was performed by Gomberg (14). 

GOMBERG - BACHMANN - GRAEBE - ULLMANN Arylatwn Atykaryl bond formation via diazonium salts Carbazole synthesis by intramolecular aryl-aryl bond formation. 

Radicaloid substitution has not been extensively studied in the thiophene series. Molecular orbital calculations indicate that substitution should occur in the a-position. This has been found to be the case in the Gomberg-Bachmann coupling of diazohydroxides with thiophenes which has been used for the preparation of 2-(o-nitro-phenyl) thiophene, 2-(p-toluyl) thiophene, " " and 2-(p-chloro-phenyl)thiophene. " Coupling in the /8-position has been used for the preparation of 1,3-dimethyl-4,5-benzisothionaphthene (148) from 2-amino-tt-(2,5-dimethyl-3-thienyl)cinnamic acid (149). A recent investigation describes the homolytic phenylation of 2- and 3-phenyl-... 

A modification of the Gomberg reaction involves the use of acetate instead of hydroxide ions, the process then being analogous to the decomposition of acylarylnitrosamines. 

Pyridine has been phenylated with the following free-radical sources benzenediazonium chloride with aluminum trichloride the Gomberg reaction " phenylhydrazine and metal oxides A -nitroso-acetanilide dibenzoyl peroxide phenylazotriphenylmethane di-phenyliodonium hydroxide and electrolysis of benzoic acid. ° Although 2-phenylpyridine usually accounts for over 50% of the total phenylated product, each of the three phenyl derivatives can be obtained from the reaction by fractional recrystallization of the... 

In a search for new spasmolytics, Heilbron and Hey and their co-workers synthesized a number of pyridylquinolines by coupling diazotized arainoquinolines with pyridine. Pyridine has also been substituted by the 3-pyridyl radical in the Gomberg reaction, the 2-and 3-substituted products being obtained in 55 and 5% yield, respectively, together with a third product obtained in 20% yield w hich w as tentatively formulated as the 4-isomer. The same radical w as coupled with 4-methyl- and 4-ethyl-pyridine and gave in each case mixtures of the twm possible substitution products in which the radical had coupled predominantly with the carbon atom of pyridine adjacent to the alkyl substituent, as showm in Eq. (19). ... 

The arylation of furan by the Gomberg reaction has been carried out using a number of differently substituted diazonium salts. In... 

There is an early report that thiophene reacts at the 3-position in phenylation with benzenediazonium chloride and aluminum trichloride, but in the Gomberg reaction thiophene has been found to substitute mainly at the 2-position both with p-tolyl and with p-chloro-phenyl radicals.Bcnzothiazole is phenylated at the 2-position in low yield by dibenzoyl peroxide a small quantity of the 4-isomcr is also obtained. ... 

Arenediazonium species 1 can be reacted with another aromatic substrate 2, by the Gomberg-Bachmann procedure, to yield biaryl compounds 3. The intramolecular variant is called the Pschorr reaction ... 

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