Grignard reagents reaction with diazonium salts

G. Reaction of Diazonium Salts with Grignard and Related Reagents. 307... 

Variable yields of azo compounds were also obtained from reactions of Grignard reagents with diazonium salts, but benzenediazonium tetrafluoroborate gave acceptable yields from arylmagnesium bromides or t-butylmagnesium chloride in THF [19] ... 

The reaction of diazonium salts with carbanions in protic solvents (Japp-Klingeman reaction) is well known. It has now been reported that Grignard reagents derived from aromatic or tertiary bromides are converted into azocompounds with substantial improvement in yields, by a modified procedure. 

Grignard reagents and diazonium zinc chloride double salts have been used to prepare azo compounds. The reaction of arylzinc chloride with a diazonium salt has also been used. By this means, mixed aromatic-aliphatic azo compounds have been prepared. 

Hydrazines may also be obtained via amidocuprates (Eq. 47)54 but the yields are low. Addition of Grignard reagents to diazonium salts provides azo compounds, which may be reduced to hydrazines. Yields in the former reaction are often low and the requirement to use dry diazonium salts adds a potential hazard. The best yields are obtained with o-benzenedisulfonimide salts (Eq. 48).191... 

RCOX, SF4, X2, HOX, or RX with alcohols, ethers, diazonium compounds, Grignard reagents, silver salts of acids, acids, amides, aromatic compounds, aldehydes, ketones, olefins, and amines. Many other organic compounds also undergo these reactions. 

Contrary to benzo[b]thiophen, benzo[b]selenophen is acylated at position 2. 2-Bromobenzo[b]selenophen, prepared from the 2-lithium derivative and bromine, is acylated at position 3, and from this derivative the 3-isomers could be synthesized. A large number of 2- and 3-aroylbenzo[b]seleno-phens were synthesized, either by Friedel-Crafts reaction of benzo-[bjselenophencarboxylic acid chlorides and benzenes or from benzol bjselenophens and benzoic acid chlorides. Also the reaction between Grignard reagents and nitriles was used for the synthesis of aroylbenzo[b]selenophens. 4,S-Diaminobenzo[b]selenophen has been synthesized via nitration of 5-aminobenzo[b]selenophen or via the reaction of the diazonium salt derived from the S-amino-derivative with p-sulphanilic acid. From the diamino-derivative, several fused benzo[b]selenophens, e.g. (525), (526), and (527), were prepared. Reaction of the phenyl-... 

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