Biphenyl-4,4’-dialdehyde

Fig. 4.4. Preparation of a silica gel surface functionalised with pairs of amino groups at a definite distance apart. The distance between the groups (about 0.70 nm) is fixed by using biphenyl-4,4 -dialdehyde as the template [4,86].

Zinc dust distillation of laurifonine, C20H25NO3, produced 2,3,6-tri-methoxyphenanthrene (1) and two successive Hofmann degradations followed by oxidative cleavage generated the biphenyl dialdehyde 2 (see Scheme 18.1). The location of the substituents in 1 and 2 was confirmed by short syntheses. ... 

The reaction was of great utility in the determination of structure of the dibenzo-p-dioxin bisbenzylisoquinoline alkaloids micranthine and telobine (Bick et al. 1972) and the alkaloid phlebicine (Cava et al. 1974). In each case, the products resembled those derived from fragmentation via electron impact and the top half of the alkaloid was characterized as an aminolactam (up to 30% yield) with the carbonyl function being on that side of the alkaloid unsubstituted at C-8 or C-8 The lower half of the alkaloid was consistently identified as a biphenyletherdialdehyde or a biphenyl-dialdehyde (less than 50% yield) and characterized as the reduced diol. The initial... 

Phenanthrenequinone has been prepared by treatment of phe-nanthrene with chromic acid in acetic acid 5 potassium dichromate in sulfuric acid 3-6 hydrogen peroxide in acetic acid 6 7 and selenium dioxide above 250°.8 It can also be prepared from benzil with aluminum chloride at 120° 9 and from biphenyl-2,2 -dialdehyde with potassium cyanide.10... 

Finally, dianils of aromatic dialdehydes may react with 2 moles of a p-tolyl-substituted heterocycle. For example, 5-phenyl-2-(p-tolyl)-1,3,4-oxadiazole (71) reacts with Schiff s base from 2 moles of p-chloroaniline and 4,4 -diformylbiphenyl (72) to give 4,4 -bis[4-(5-phenyl-l,3,4-oxadiazol-2-yl)styryl]biphenyl (73).43 Along with further p-tolyl-substituted heteroaromatics, a number of carbocyclic aromatics have... 

Formyl-benzophenon 7, 768. Biphenyl-d]ald >(2.2 ) 7 I 38ft I>9henyl-dialdehyd-(4.4 7, 768. Sfediyl-aeelyl-beDzoyleD-Gyclobntadien 7, 769,1 397. 

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