Biphenyl benzoylation

Benzoyl azide Biphenyl triozonide Boron tribromide Bromine azide Bromine solutions... 

Dimethoxybenzoyl chloride Benzoyl chloride, 2,3-dimethoxy- (9) (7169-06-4) 2-Amino-2-methyl-1-propanol 1-Propanol, 2-amino-2-methyl- (8,9) (124-68-5) 2,2 -Dimethoxy-6-(4 ,4 -dimethyloxazolinyl)biphenyl Oxazole, 2-(2 ,6-dimethoxy[1,1-biphenyl]-2-yl)-4,5-dihydro-4,4-dimethyl- (9) (57698-39-7)... 

The benzanthrone system is susceptible to both electrophilic and nucleophilic attack. The most reactive sites towards electrophiles are the 3- and 9-positions, which can be compared with the 4,4 -positions in biphenyl. The 9-position is somewhat deactivated by the carbonyl group, however. Thus, for example, monobromination takes place at the 3-position and further substitution gives 3,9-dibromobenzanthrone. Nitration and benzoylation similarly give rise to the 3-substituted product. The 3-position is in fact peri-hindered (compare naphthalene) so that sulphonation yields the 9-sulphonic acid. Electron withdrawal by the carbonyl group activates the 4- and 6-positions towards nucleophilic attack for example, hydroxylation occurs at these sites. 

The partial rate factors for dibenzofuran relative to a benzene position, for protodetritiation, protodetrimethylsilyIation, nitration with nitric acid in acetic anhydride, and benzoylation with benzoyl chloride and aluminum chloride in nitrobenzene at 15°C are shown in Table VII along with the relevant values for diphenyl ether, It is seen that by introducing the biphenyl bond in diphenyl ether the reactivity is lowered at both the positions ortho (4-) and para (2-) to the oxygen of dibenzofuran. This lowering of reactivity has been attributed to the fact that the 2- and 4-positions, as... 

Benzidine (based dyes) Benzo(a)pyrene Benzoyl peroxide Benzyl chloride Beryllium and compounds Biphenyl Bismuth lelluride Borates, lelra, sodium salts Boron oxide... 

Research utilizing the thiepine skeleton in material science has been reported. For example, liquid crystals with chiral dihydrodibenzo[c,i ]thiepines were studied. The enantiomerically pure (-)-(i )-3,9-bis[4-(dodecyloxy)benzoyl-oxy]-5,7-dihydro-l,l l-dimethyldibenzoR,f]thiepine 80 and (—)-(R)-3,9-bis[4-(dodecyloxy)benzoyloxy]-5,7-dihydro-1,1 l-dimethyldibenzoR,f]thiepine dioxide 82 display smectic C mesophases by a rigid twisted biphenyl core and axial chirality <1998JOC3895>. 

Similar results have been obtained with other peroxides and benzene derivatives. A 29% yield of p-terphenyl can be obtained by careful decomposition of benzoyl peroxide in molten biphenyl at 950.86... 

In the years since 1998, some papers have reported the benzoylation of substituted benzene derivatives, such as toluene, [9-11] ethyl benzene,[11] xylene,19 11 121 anisole/9 131 dimethoxybenzene,[14] biphenyl/151 phenol[16] and chlorobenzene1171 in the presence of zeolites and, in most cases, particularly H-BEA zeolite. 

Chidambaram, M., Venkatesan, C., Moreau, P., Finiels, A., Ramaswamy, A. V. and Singh, A. P. Selective benzoylation of biphenyl to 4-phenylbenzophenone over zeolite H-beta, Appl. Catal., A, 2002, 224, 129-140. 

Figure 9. Proton-nmr spectra recorded (A) before and (B) during the photolysis of 4-benzoyl biphenyl in isopropanol.

Benzidine Benzoic trichloride (Benzotrichloride) Benzoyl chloride Benzoyl peroxide Benzyl chloride Beryllium Biphenyl... 

Approximately 3 g of benzoyl peroxide are added to 20 kg of wheat flour. This is then easily decomposed to benzoic acid and other substances such as biphenyl and phenylbenzoate (Be-Onishi et al., 2004). Aqueous solutions of 2.5% of the sodium salts of organic acids are adequate to maintain the chemical quality and extend the shelf life of fresh salmon with only minor sensory changes during refrigerated storage (Sallam, 2007b). In carcass surface applications 2% lactic, 1.5% acetic plus 1.5% propionic acids are usually applied (Dubai et al., 2004). 

Benzophenone synthase (BPS) and biphenyl synthase (BIS) catalyze the formation of the same linear tetraketide from benzoyl-CoA and three molecules of malonyl-CoA. However, BPS cyclizes this intermediate via intramolecular C6-+C1 Claisen condensation, whereas BIS uses intramolecular C2— C7 aldol condensation. Benzophenone derivatives include polyprenylated polycyclic compounds with hi pharmaceutical potential. Biphenyl derivatives are the phytoalexins of the economically important Maloideae. 

Type III polyketide synthases (PKSs) generate a diverse array of natural products by condensing multiple acetyl units from malonyl-CoA to specific starter substrates (1,2). The homodimeric enzymes orchestrate a series of acyltransferase, decarboxylation, condensation, cyclization, and aromatizatidn reactions at two functionally independent active sites. Due to their ability to vary either the starter molecule or the type of cyclization and the number of condensations, they are, along with terpene synthases, one of the major generators of carbon skeleton diversity in plant secondary metabolites (i). Among the starter substrates used, benzoyl-CoA is a rare starter molecule. It is utilized by bacterial type I PKSs to form soraphen A, enterocin and the wailupemycins (4). in plants, benzoyl-CoA is the starter unit for two type III PKSs, benzophenone synthase (BPS) and biphenyl synthase (BIS), both of which were cloned in our laboratory. 

The photolysis of the benzoate of thiophenol produces benzoyl radicals and thiyl radicals which react further to give benzaldehyde, diphenylsulphide and biphenyl. This reaction has been examined for its potential for the initiation of radical polymerisation processes. ... 

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