Diphenyl succinate

Reactions with Sulfur Compounds. Thiosuccinic anhydride [3194-60-3] is obtained by reaction of diethyl or diphenyl succinate [621-14-7] with potassium hydrogen sulfide followed by acidification (eq. 10). Thiosuccinic anhydride is also obtained from succinic anhydride and hydrogen sulfide under pressure (121). 

As the mechanism, a radical and a cationic pathway are conceivable (Eq. 31). The stereochemical results with rac- or mcjo-1,2-diphenyl succinic acid, both yield only trans-stilbene [321], and the formation of a tricyclic lactone 51 in the decarboxylation of norbornene dicarboxylic acid 50 (Eq. 32) [309] support a cation (path b, Eq. 31) rather than a biradical as intermediate (path a). 

DIPHENYL SUCCINATE (Succinic acid, diphenyl ester)... 

A mixture of 118 g. (1 mole) of succinic acid, 188 g. (2 moles) of phenol, and 138 g. (83 ml., 0.9 mole) of phosphorus oxychloride (Note 1) is placed in a 2-1. round-bottomed flask fitted with an efficient reflux condenser capped with a calcium chloride tube (Notes 2 and 3). The mixture is heated on a steam bath in a hood (Note 3) for 1.25 hours, 500 ml. of benzene is added, and the refluxing is continued for an additional hour. The hot benzene solution is decanted from the red syrupy residue of phosphoric acid and filtered by gravity into a 1-1. Erlenmeyer flask. The syrupy residue is extracted with two 100-ml. portions of hot benzene, which are also filtered into the Erlenmeyer flask. The combined benzene solutions are concentrated to a volume of about 600 ml. (Note 4), and the pale yellow solution is allowed to cool, whereupon the diphenyl succinate separates as colorless crystals. It is filtered with suction on a Buchner funnel, washed with three 50-ml. portions of ether, and dried on a porous plate at 40°. The yield of diphenyl succinate, m.p. 120-121°, is 167— 181 g. (62-67%) (Note 5). 

If desired, a second crop may be obtained by the following procedure The mother liquor is extracted in a 1-1. separatory funnel with eight 50-ml. portions of 5% potassium hydroxide solution. Each extract is extracted in turn with a 50-ml. portion of benzene. The two benzene solutions are washed in turn with a 50-ml. portion of water and two 50-ml. portions of saturated sodium chloride solution. All the benzene solutions are combined, dried over anhydrous sodium sulfate, filtered, and concentrated to a volume of 150 ml. Cooling yields a second crop of diphenyl succinate, which is collected, washed, and dried as described for the first crop. The yield is 13-27 g. (5-10%), m.p. 118-120°. 

The above procedure is a modification of that described by Rasinski.2 Diphenyl succinate has also been prepared by the reaction of phenol and succinic acid in the presence of phosphorus pentoxide in toluene8 and by the treatment of phenol with succinyl chloride.4... 

Diphenyl succinate Phenyl benzoate Phenyl cinnamate Diphenyl carbonate... 

Corey and Casanova found that oxidation of either meso- or dM, 2-diphenyl-succinic acid with lead tetraacetate in pyridine afforded tranr-stilbene (40-45% yield) cw-stilbene was shown not to be an intermediate. Similar oxidation of either endo- or exo-norbornane-2-carboxylic acid gave cjco-norbornyl acetate (24-67%). 

Phenyl esters. Preparation of diphenyl succinate. The use of more than 0.9 mole of POCI3 did not improve the yield and gave an inferior product. The mixture... 

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