Dimethyl diphenate

Methyl o-iodobenzoate is converted under these conditions (equation 11) into methyl salicylate (main product) and dimethyl diphenate (minor product). If the cuprous salt is replaced by the cupric salt, hydrolysis is essentially the only reaction (equation III). If ammonium tetrafluoroborate is added, methyl benzoate is the only product. 

Dimethyl-diphen -dicarboii84are-(x.x)-diAthylester 9 1 407. y-Methyl-y-[naphthyl-(2)]-itacoii8aure. 

The aldehyde 38 was obtained from 35, by way of 36 and 37, by the carbodiimide—dimethyl sulfoxide oxidation procedure52 in the presence of 3-(3-dimethylaminopropyl)-l-ethylcarbodiimide hydrochloride (EDAC)53 and dichloroacetic acid. It was isolated in the form of its crystalline 1,3-diphenylimidazolidine derivative (39) by trapping the freshly prepared aldehyde 38 with N,N -diphen-ylethylenediamine. (This reagent was developed by Wanzlick and Lochel54 for the selective derivatization of aldehydes, and has been exploited for the isolation of nucleoside 5 -aldehydes55 and other aldehydo derivatives of carbohydrates by Moffatt and coworkers.52(b))... 

Dimethyl-188 and 2,6-dimethylpyrazine react very similarly to methylpyrazine. Thus, 2,6-dimethylpyrazine can be converted into a monoanion with sodamide in liquid ammonia which can be condensed with aldehydes and ketones,179 acylated with esters,181 and alkylated with alkyl halides181 to give the corresponding 2-methyl-6-substituted pyrazines. Acylation under suitable conditions also yields diacylated derivatives. Thus, when 2,6-dimethylpyrazine, sodamide, and ethyl benzoate are reacted in 1 3 2 molecular proportion, 38% 2,6-diphen-acylpyrazine (35) and 25% 2-methyl-6-phenacylpyrazine (36) is obtained. From the preparative point of view it is better to form the diacyl derivative by the further acylation of the monoacyl derivative rather than by direct diacylation.187... 

Dihydroquinazolines are in equilibrium with 3,4-dihydroquinazolines, which are generally thermodynamically more stable. In order to obtain 1,4-dihydroquinazoIines it is necessary to have a substituent at N-1 so as to freeze the tautomerism. The proportion of l//-l,4-hydroquinazoline produced in a kinetically controlled reaction can, however, be appreciable. This is demonstrated in the following reactions. 4-Phenylquinazoline was reduced with sodium in tetrahydrofuran to the monomeric dianion. When the dianion was treated with water or one equivalent of methyl iodide, only 4-phenyl- and 4-methyl-4-phenyl- 3,4-dihydroquinazolines were isolated. If, however, two molecular equivalents of methyl iodide were added, a mixture of 1,4-dimethy 1-4-phenyl- (16%) and 3,4-dimethyl-4-phenyl- (42%) 3,4-dihydroquinazolines was formed. The monomeric dianion of 2,4-diphen-ylquinazoline gave l,4-dimethyl-2,4-diphenyl- and 3,4-dimethyl-2,4-diphen-yl-3,4-dihydroquinazoline in 60% and 27% yields, respectively, with methyl iodide. If ethyl chloroformate was used as alkylating agent, on the other hand, an 85% yield of l,4-bisethoxycarbonyl-2,4-diphenyl-3,4-dihydroquin-azoline was formed. A similar behavior was observed when methyl lithium reacted with 2,4-diphenylquinazoline followed by methylation of the intermediate lithium salts [Eq. (8)]. ... 

Sakamoto et al. provided an example of absolute asymmetric synthesis involving hydrogen abstraction by thiocarbonyl sulfur [21]. Achiral A-diphen-ylacetyl-A-isopropylthiobenzamide 26a and A-diphenylacetyl-A-isopropyl(p-chloro)thiobenzamide 26b crystallize in chiral space group P2i2i2i (Scheme 13). Photolysis of the chiral crystals in the solid state gave optically active azetidin-2-ones 27, whereas achiral thioketones 28 were obtained as main products. When 26a was irradiated in the solid state at - 45°C followed by acetylation (at - 78°C), 2-acetylthio-3,3-dimethyl-l-diphenylacetyl-2-phenylaziridine (30a 39% yield, 84% ee), 4-acetylthio-5,5-dimethyl-2-diphenylmetyl-4-phenyloxazoline (31a 10% yield, 50% ee), 3,3-diphenyl-l-isopropyl-4-phenylazetidin-2-ones (29a 16% yield, 20% ee), thioketone (28a 15%) and A-isopropylthiobenzamide (15%)... 

Reduction. The reagent is useful for reduction of carboxylic acid esters to primary alcohols. For example, the following esters have been reduced to the corresponding carbinols ethyl p-nitrobenzoate (96% yield), ethyl phenylacetate (90% yield), ethyl gly-cinate (70% yield). The reaction has some useful features Hydroxylic solvents (ethanol, water) can be used, the selectivity is higher than in the case of lithium aluminum hydride, and the reagent is nearly neutral. The reagent was found to be satisfactory for reduction of the dimethyl ester of 4,4 -dinitro-2,2 -diphenic acid (la) to the corresponding alcohol (lb, 51%yield).2... 

DIPHENIC ACIDS 2-(o-Methoxyphenyl)-4,4-dimethyl-2-oxazoline. DIPHENYLACETYLENES N,N,N, N -Tetramethyldiaminophosphorochloridite. DISULFIDES 2,4-Dinitrobenzenesulfenyl chloride. 

Diphenylsuccinic acid, A43.7, X"7 6-Benzyloxycoumaran-2-carboxylic acid, Y1.12 6,6 -Dimethyl-2,2 -diphenic acid, X5.8... 

C2 9H3 5CIN2O3, 4-(p-Chlorophenyl)-4-hydroxy-N,N-dimethyl-a,a-diphen-ylpiperidine-1-butyramide hydrate, 43B, 315 C3 0H3 2Ni,, 1,2,4,5-Tetrabenzylhexahydro-s-tetrazine, 44B, 223 C3 0H3 5CIN2O2, 4-(p-Chlorophenyl)-4-hydroxy-N,N,7-trimethyl-a,a-di-phenyl-1-piperidinebutyramide, 43B, 315 C30H35F2N3O, 4-(4,4-Bis(p-fluorophenyl)butyl)-1-piperazineacetyl-2 ,6 -xylidide, 43B, 316... 

The second promising new type of polymer was made from 2,2 -diphenylethynyl-4,4 -diphenic acid units which cure on heating to give phenylbenzanthracene units in the polymer chain. The new polymer also belongs to the polyaromatic ether-keto-sulfone series. This polymer was prepared from dimethyl 4,4 -diphenate by direct iodination in sulfuric acid with a silver sulfate catalyst to give the 2,2 -diiodo derivative in 80-85% yield. When hydrolized to the acid it could be converted to the acid chloride on treatihent with oxalyl chloride in pyridine solution. 

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