Benzoyl -3 Benzofuran

TREATMENT OF GOUT AND HYPERURICAEMIA BY BENZBROMARONE ETHYL 2 (DIBROMO -3,5 HYDROXY - 4 BENZOYL) - 3 BENZOFURAN... 

Auwers and others soon discovered that the transformation 3 —> 6 did not consistently give flavonols such as 2. For example, alcoholic alkali treatment of dibromide 11 produced 2-benzoyl-benzofuran-3-one 12 instead of the corresponding flavonol. The same observation was made by Robert Robinson in a failed attempt to make datiscetin in 19257 It has reported that when there is a meta (to the coumarone ring oxygen) substituent such as methyl or methoxy, flavonol formation is hindered, whereas methyl, methoxy, and chlorine substituents at the ortho and para positions are conducive to flavonol formation. ... 

The corresponding 3,5-dibromo derivative is benzbromarone, which is less active. The last two compounds are, besides, powerful urico-eliminators 30a 2-ethyl-3-(3,4,5-trimethoxybenzoyl)benzofuran (23c)66 and 2-butyl-3-[3,5-diiodo-4-(2-diethylaminoethoxy)benzoyl]benzofuran or amiodarone (24) (or Cordarone67) are powerful angiotropics. 

Electrophilic substitution and metallation reactions of [l]benzothieno[3,2-3][l]benzofuran 63 were studied <2000CCC58>. Bromination, acetylation, benzoylation, formylation, and nitration usually afforded inseparable mixtures of 2- and 7-substituted derivatives as the main products. Disubstitution reactions preferably led to 2,7-disubstituted derivatives. [l]Benzothieno[3,2-3][l]benzofuran-10,10-dioxide 64 and [l]benzothieno[3,2-3][l]ben-zofuran-lO-oxide 65 can be selectively obtained by oxidation of 63. Mononitration of 64 and 65 led selectively to corresponding 7-nitro derivatives, respectively. Only sulfoxide 65 was successfully reduced. 

The carbonyl compound (161), obtained by hydrolysis of 3-benzoyl-2(3//)-benzofuranone (160),407 gives the benzofuran derivative (150) (R1 = H, R3 = COOH, Ar = Ph). The same occurs with the product of the abnormal Chapman rearrangement 395 of iV-phenylbenzimino o-(carbomethoxymethyl) phenylether. 

To resolve the question of the connection of spermine with the benzofuran system, the compounds 185 (Scheme 33) and 186 (Scheme 34) were prepared and analyzed. In 179 the units are connected by three bonds, two of which are amide bonds. One of the amides is N-monosubstituted and must therefore represent one end of the spermine unit. By treatment of 180 with benzoyl chloride this N-substituted amide is transformed to an N-sub-stituted secondary amid (imide), which under mild hydrolysis conditions [preferred cleavage of the N-23—C-24 bond] followed by esterification yielded 185. Deuteration experiments, transformation reactions with 185, as well as extensive spectroscopic investigations, have shown that in 179 N-23 is connected to C-24 and not to C-19. 

Benzofuran 3,6-Dimethyl-2-ethoxycarbonyl-4-hydroxy-E6b/1, 122 ( —H2 Enolisier.) Butansaure 2-Benzoyl-3-oxo- -ethylester Vll/2a, 522 f. (Acy-lier.) VIII, 610 (Acylier.)... 

SYNS BENZOFURAN, (2-ETHYL-3-(4 -HYDROXY-BENZOYL)) 2-ETHYL-3-BENZOFURANYL p-... 

SYNS BENZOFURAN, 3-(p-(2-(DIETHYLAMINO)-ETHOXY)BENZOYL)-2-ETHYL- p-(2-(DIETHYL-AMINO)ETHOXY)PHENYL 2-ETHYL-3-BENZOFURAN-YL KETONE KETONE, p-(2-(DIETHYLAMINO)ETHO-XY)PHENYL 2-ETHYL-3-BENZOFURANYL L 2642-LABAZ METHANONE, (4-(2-(DIETHYLAMINO)ETHO-XY)PHENYL)(2-ETHYL-3-BENZOFURANYL)-(9CI)... 

An isobenzofuran is obtained in good yield when the bromo-hydrazone (9.2) is treated successively with methyllithium, butyllithium, benzoyl chloride and an excess of lithium bromide. Recent developments in the chemistry of benzofurans have been reviewed (3894, 3983]. 

Quinoxaline di-iV-oxides without substituents in the pyrazine ring have been prepared by reaction of benzofuroxans with synthons of the type RCH==CHX, where R = COMe or 4-substituted benzoyl and X = ONa, or where R = H and X = NR2 or OAc. - Two cases are known of mono-N-oxide rather than di-N-oxide formation using benzofuroxan. Thus reaction with benzofuran-3(2H)ones gives 3-(o-hydroxyaryl)quinoxaline... 

Application of this photocyclization to polymers, such as 4, should afford an effident photochemical route to the synthesis of ordered polymer systems based upon a phenyl substituted benzofuran repeat unit (Scheme II). Due to a fair degree of molecular flexibility, photopolymer 4 should be soluble in a variety of organic solvents. Photocyclization of 4 could then be carried out either in solution or the solid state (films, fibers, or coatings). This paper describes the photochemistry of low molecular w/eight formulations of 4 (n- 1,5,10) and that of an appropriate model compound, 1,4-bis(2-benzyioxy-benzoyl)benzene, 4a. 

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