2-bromo-2 -biphenylyl-

When arsonium salt 120-1 is treated with lithium aluminum hydride in tetra-hydrofurane at —70 °C copious evolution of hydrogen occurs and a red solution is obtained, whose color fades on warming to room temperature. Hydrolysis yields only 2-biphenylyl-2,2 -biphenylylenearsine (124). The same deep red solution and colorless hydrolysis product 124 are obtained when 2 -bromo-2-biphenylyl-2,2 -biphenylylenearsine (147) is first reacted with t-butyllithium in tetrahydrofurane... 

Phenanthridone has been obtained by the action of carbon dioxide on 2-lithioaminobiphenyl49 and by cyelizing 2-biphenylyl isocyanate with aluminum chloride,50 the latter reaction appearing to be a general one. Thus, cyclization of 5-bromo-2-biphenylyl isocyanate gives 2-bromophenanthridone,51 while reaction of the isocyanate (17) with trifluoroacetic acid is a key stage in the synthesis of dihydroxy-crinene (18).52... 

Willow-like cascade construction was facilitated by the preparation of the AB2-type building blocks, e.g., 6-bromo-l-(4-hydroxy-4 -biphenylyl)-2-(4-hydroxyphenyl)hexane (40 Scheme 6.12), 13-bromo-l-(4-hydroxyphenyl)-2-[4-(6-hydroxy-2-naphthalenylyl)-phenyljtridecane (41), and 13-bromo-l-(4-hydroxyphenyl)-2-(4-hydroxy-4"-p-terpheny-lyl)tridecane (42). Scheme 6.12 illustrates the monomer preparative strategy for the incorporation of the monomeric mesogenic moieties predicated on conformational (gauche versus anti) isomerism. Thus, one equivalent of 4-hydroxybiphenyl was allowed to react with 1,4-dibromobutane to yield the monobromide 43, which was converted under Finkelstein conditions to the corresponding iodide 44. Treatment of the latter with ketone 45 under phase transfer conditions afforded the a-substituted ketone 46. Reduc-... 

Other compounds that have been similarly synthesized are 2,4-bis(4-methoxyphenyl)furan, 2,4-bis(4-biphenylyl)furan, 2,4-bis(4-bromophenyl)furan, 2,4-bis(4-chlorophenyl)furan, and 2,4-bis(4-nitrophenyl)furan. When MeOH (a proton donor) is added to the system containing phenacyl bromide [232], the principal products are acetophenone (53%) and 2-bromo-l,3-diphenyl-3,4-epoxy-butan-l-one (37%). If, to DMF containing lithium perchlorate and ethyl bromoacetate, phenacyl bromide is slowly introduced and reduced at mercury, the distribution of products is different [233] ... 

Synonyms 1,1-Biphenyl, 4-bromo- 4-Biphenylyl bromide p-Biphenylyl bromide p-Bromobiphenyl 4-Bromodiphenyl p-Bromodiphenyl (4-Bromophenyl) benzene p-Phenylbromobenzene p-Phenylphenyl bromide... 

Polyether dendrimers (thermotropic) Monomers 6-bromo-1-(4-hydroxy-4 -biphenylyl)-2-(4-hydroxyphenyl)hexane (TPH) 13-bromo-1 -(4-hydroxyphenyl)-2- [4-(6-hydroxy-2-naphthalenylyl)-phenyl]tridecane (BPNT) 13- bromo-1-(4-hydro-xyphenyl)-2-(4-hydro-4"-p- terphenylyl)tridecane (TPT) Chain ends benzyl or allyl or alkyl. TPH and BPNT show narrow nematic meosphase TPT nematic mesophase extends over 82 °C. Degree of branching for TPT with allyl end is 0.82. [137]... 

KOH and diethylene glycol until the temp, reaches 185°), and refluxed 5 hrs. with stirring -> di-(4 -bromo-4-biphenylyl)-methane. Y 82%. F. e. s. 

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