Biphenyl 4,4 -diformyl

In contrast to biphenyl-2,2 -dicarbaldehyde, the corresponding diformyl derivative of 1,1 -binaphthyl can be transformed to the annulated 1,2-diazocine derivative.21... 

Dimethylamino-methyl)-2-hydroxymethyl-aus 2 -Carboxy-2-(dimethylaminocarbonyl)-biphenyl und Lithiumalanat 165 2,2 -Dinitro- 474, 476, 695 6,6 -Dinitro-2,2 -bis-[chlorcarbonyl]- 188 2,2 -Dinitro-4,4 -bis-[diathylamino]- 695 4,4 -Dinitro-2,2 -bis-rhydroxymethyl]- 213 6,6 -Dinitro-2,2 -bis-[hydroxymethyl]- 188 2,2 -Dinitro-4,4 -diamino- 695 6,6 -Dinitro-2,2 -diformyl- 694 4,4 -Dinitro-2,2 -dimethoxycarbonyl- 213 2,2 -Dinitro-4,4 -dimethyl- 695 6,6 -Dinitro-2 -formyl-2-carboxy- 694 2,2 -Dinitroso- 476 -4-hydroxamsaure-chlorid 537 4-(a-Hydroxy-benzyl)- 542 Methoxy- 678 2-Methyl- 556 Nitro- 672, 678 4-Nitro- 687... 

Mit Arylhydrazinen reagiert 2,2 -Diformyl-biphenyl zu 9-Arylazo-phenanthrenen, die durch Kondensation von Nitroso-benzolen mit 9-Amino-phenanthren nicht zuganglich sind (2,2 -Diformyl-biphenyl kann mittels Ozonolyse von Phenanthren in 65-85% Aus-beute hergestellt werden). Die Ausbeuten sind hoch (60-90%)3. Es ist moglich, anstelle der freien Hydrazine auch die Hydrochloride einzusetzen ... 

The electrophilic formylation of arenes with CO in the presence of acids (Gatterman-Koch conditions) is an efficient method for preparing aromatic aldehydes. HF-SbFs-SO2CIF is the most active system for this reaction [82]. It has been demonstrated that even diformylation can be achieved on polymeric aromatics such as biphenyl with the use of fluoroantimonic acid (Eq. 36) [83]. 

The breakdown of the benzene ring to aldehydes is extremely rare and has been achieved only by ozone. A historical and classical example is the disintegration of o-xylene to a mixture of glyoxal, methyl glyoxal, and diacetyl (butanedione) in the predicted ratios [104]. From the preparative point of view, the conversion of phenanthrene into 0,0 -diformyl-biphenyl (diphenaldehyde) [1123] or o-formylbiphenyl-o -carboxylic (diphenaldehydic) acid [1124] is more important (equation 154). 

The HF-SbFs system works well in the Gattermann-Koch formylatlon of arenes and the Koch carbonylation of alkanes [54]. For instance, biphenyl is diformylated in HF-SbFs-CO to afford 4,4 -diformylbiphenyl as a major isomer (Scheme 14.20). The carbonylation of alkanes with C5-C9 carbon atoms in the HF-SbFs-CO system affords mixtures of C3-C8 carboxylic acids after hydrolysis of the generated secondary carbenium ions [55]. Successive treatment of methylcyclopentane with CO in HF-SbF and with water produces cyclohexanecarboxylic acid as a major product (Scheme 14.21) [56]. It seems that a tertiary methylcyclopentyl cation readily isomerizes to the more stable cyclohexyl cation before being trapped by CO. Bicyclic a, -unsaturated ketones are functionahzed by HF-SbF or FSOsH-SbFs under a CO atmosphere to give saturated keto esters after methanolysis (Scheme 14.22) [57]. Alcohols with short carbon chains also react with CO in HF-SbFs to give the corresponding methyl esters [58]. y-Butyrolactones are carboxy-lated under the same conditions to afford 1,5-dicarboxyhc acids [59]. 

Hydroxy-3-methoxybenzaldehyde (vanillin) in acetonitrile containing potassium bicarbonate upon treatment with 1-oxo-2,2,6,6-tetramethylpiperidinium fluoroborate gave (dehydrovanillin), 2,2 -dihydroxy-3,3 -dimethoxy-5,5 -diformyl-biphenyl in 85% yield (ref.41). 

A solution of 4-bromobenzaldehyde (106, 1.85 g, 10 mmol) in dry A, A -dimethyl formamide (10 ml) was added dropwise to a suspension of bis(l,5-cyclo octadiene)nickel(O) (Ni(COD)2, 1.53 g, 5.6 mmol) in A,/V-dimethylformamide (10 ml) under nitrogen at 25 °C. The reaction mixture was stirred at 35 C for 20 h, then partitioned between 3% aqueous hydrochloric acid (20 ml) and dichloromethane (20 ml). After being filtered to remove a finely divided nickel, the organic layer was washed with water, dried (Na2S04), and concentrated to dryness. The residue was purified with diethyl ether (2-3 ml) to obtain 0.83 g (79%) of pure 4,4 -diformyl biphenyl (105) as colourless crystals. 

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