1015-80-1

Upstream product

• 75-09-2 dichloromethane 
• 605-39-0 2,2'-dimethyl-1,1'-biphenyl 
• 85-01-8 phenanthrene 
• 264-08-4 benzocycloheptatrien 
• 219-92-1 dibenzocycloheptene 
• 91-20-3 naphthalene 
• 91900-08-2 7,7'-Bi(1,2:3,4-dibenzotropyl) 

Downstream Products

• 86-73-7 9H-fluorene 
• 883-20-5 9-methylphenanthrene 
• 85-01-8 phenanthrene 
• 53137-51-2 6,7-dihydro-5H-dibenzocyclohepten-5-one 

Relevant academic research and scientific papers

Thermal Reorganizations of 1,2:3,4-Dibenzotropilidene (5H-Dibenzocycloheptene), 7,7'-Bi(1,2:3,4-dibenzotropyl) cycloheptenyl)>, and the 1,2:3,4-Dibenzotropyl (Dibenzocycloheptenyl) Free Radical

1,2:3,4-Dibenzotropilidene (5H-dibenzocycloheptene, 8) has been shown to thermally produce phenanthrene (12), 9-methylphenanthrene (13), 9,10-dihydrophenanthrene (14), and 1,2:3,4-dibenzocycloheptadiene (6,7-dihydro-5H-dibenzocycloheptene, 15).With added naphthalene, to trap the extruded one-carbon species, 1,2-benzotropilidene (16), α-methyl- and β-methylnaphthalene (17 and 18), 1,2-benzo-1,3-cycloheptadiene (19), and benzocycloheptene (20) were also produced.Reaction of 1,2-benzotropilidene with phenanthrene produced 1,2:3,4-dibenzotropilidene (8) and naphthalene, showing the reversibility of this thermal carbon extrusion reaction. 7,7'-Bi(1,2:3,4-dibenzotropyl) cycloheptenyl), 10> was prepared by VCl2 reduction of the 1,2:3,4-dibenzotropylium cation.Thermally it underwent the same reactions as 8, demonstrating that it is the 1,2:3,4-dibenzotropyl (dibenzocycloheptenyl) free radical (9) which lost a carbon atom (CH group) to the aromatic acceptor.At 200 deg C the dimer 10 produced significant quantities of 9-methylphenanthrene (13), shown not to arise from 8, in addition to phenanthrene, 12.Mechanisms for the thermal transfer of a CH group from 9 to an aromatic acceptor and for the production of 13 from 9 are presented.

Preperations and Reactions of Symmetrical Dimethylenebiphenyl Dianions; Conformations of -o-Cyclophanes. A Simple NMR method for Determining Twist Angles in Biphenyls

With n-butyllithium / potassium tert-butoxide, a proton is removed from each methyl group of the symmetrical dimethylbiphenyls to give dianions in good yield.The reactions of these dianions with alkyl halides, dialkyl sulfates, trimethylchlorosilane, trimethylchlorogermane, α,ω-dihalides, and oxidizing agents were found to provide the best routes to many symmetrically substituted biphenyls, including - and cyclophanes.NMR and molecular mechanical studies of some of these cyclophanes gave information on their preferred conformations.An NMR method for determining the angle of twist in biphenyls from the chemical shifts of the ortho hydrogens is developed.