7,7 -dimethoxy-2,2 -diphenyl

The formation of this dibenzarsenole ring system may be essayed from a different standpoint from that described in the foregoing, and to prepare 3 6-dimethoxy-o-o -diphenylylenechloroarsine, 3 3 -dimethoxy-diphenyl is used as the starting-point. ... 

A mixture of 432 g (4 mols) of anisole and 4 g of concentrated H3P04 was heated to 150° C. in a reaction vessel equipped with a stirrer, metering unit and descending condenser. After the afore mentioned temperature had been reached, 58 g (1 mol) of propionaldehyde were added through the metering unit over a period of 1.5 hours and, at the same time, the water of reaction formed distilled off. On completion of the addition, the upper phase of the reaction mixture was decanted from the phosphoric acid precipitated and the excess anisole removed from the reaction mixture by distillation, leaving 251.8 g of condensation product consisting of p,p -, o,p - and o,o -l,l-dimethoxy diphenyl propane. The yield amounted to 98.4%, based on the propionaldehyde used. 

For splitting, 100 g of 1,1-dimethoxy diphenyl propane from the condensation stage (a) were heated to 200° C. in a distillation apparatus fitted with a Claisen attachment, followed by the addition of 0.5 g of concentrated phosphoric acid. The products formed during the splitting reaction distilled off over a period of 15 minutes at about 5 to 30 Torn According to analysis by gas chromatography, the distillate (95.5 g) contained 32.7 g of unsplit 1,1-dimethoxy diphenyl propane, 24.1 g of ira .9-p-anethole, 9.1 g of trans-o- and cns-p-anethole and 1.2 g of p-propyl anisole, corresponding to a yield of 91.4% of anetholes, based on reacted condensate. 

A mixture of 324 g (3 mols) of anisole and 4 g of concentrated H3P04 was heated to 150° C. in a 500 mL. capacity reaction vessel equipped with a thermometer, stirrer and dropping funnel. After the above-mentioned temperature had been reached, 64 g (0.432 mol) of o-anethole (2-methoxy-propen-l-yl benzene) were introduced into the thoroughly stirred anisole/phosphoric acid mixture over a period of 1 hour, followed by stirring for 1 hour at the same temperature. The excess anisole was then distilled off at 50° C./5 Torr, leaving 110 g of a condensation product consisting predominantly of the o,p -isomers of 1,1-dimethoxy diphenyl propane. The yield was substantially quantitative. 

Distillation of 55 g of 1,1-dimethoxy diphenyl propane gave 17.8 g of a distillate which contained 14% of ra s-p-anethole according to analysis by gas chromatography. 24.2 g of condensate were recovered. 

Diploscliiateaa ure 10II 349. 8.8 -Dioxy 5.5 -dimethoxy-diphenyl-dlcarbons ure-(3.3 ), Dehydrodivanillim saute 10 1 289. 

C,iHmN,Oi. 4.4. Bi8.[( thoxafyl-carb thoxy-metlqrW)-hydriiadno].3.3 -dimethoxy-diphenyl 16, 616. 

Obtained by nitration of 3,3 -diacetyl-4,4 -dihydroxy-6,6 -dimethoxy-diphenyl sulfone in concentrated sulfuric acid with concentrated nitric acid at 60° for 15 min [5922],... 

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