TOLUENE Toluenesulfonic anhydride

A lO-mL round-bottomed flask equipped with a rubber septum and argon inlet needle was charged with a solution of the sulfoxide (91 mg, 0.35 mmol) in 3 mL of toluene. Acetic anhydride (0.164 mL, 0.177 g, 1.74 nunol) and p-toluenesulfonic acid (2 mg, 0.001 mmol) were added, and the flask was fitted with a reflux condenser and heated at reflux for 1 h. The resulting mixture was cooled to 25 °C and concentrated to afford 113 mg of an oil. Column chromatography on silica gel (gradient elution with 5-10% ethyl acetate-hexane) provided the mixed acetal (94 mg, 89%) as a colorless oil. 

The last synthesis to evolve which is due to Ito and his coworkers is interesting in that it relies on a stereospecific skeletal rearrangement of a bicyclo[2.2.2]octane system which in turn was prepared by Diels-Alder methodology (Scheme XLVIII) Heating of a toluene solution of cyclopentene 1,2-dicarboxylic anhydride and 4-methylcyclohexa-l,4-dienyl methyl ether in the presence of a catalytic quantity of p-toluenesulfonic acid afforded 589. Demethylation was followed by reduction and cyclization to sulfide 590. Desulfurization set the stage for peracid oxidation and arrival at 591. Chromatography of this intermediate on alumina induced isomerization to keto alcohol 592. Jones oxidation afforded diketone 593 which had earlier been transformed into gymnomitrol. 

Dimethyl a i-A -tetrahydrophthalate can be prepared by a similar procedure. cix-A -Tetrahydrophthalic anhydride (228 g., 1.5 moles) is heated under reflux with 364 ml. (9 moles) of commercial anhydrous methanol and 2.5 g. of />-toluenesulfonic acid monohydrate for 12-16 hours. At this time 270 ml. of toluene is added and the mixture is distilled. When the distillation tem- )erature drops from 68-70° to 45°, after about 4-6 hours, 364 ml. of absolute methanol is added and the mixture again is heated under reflux for 12-16 hours. An additional 270 ml. of toluene is added, and distillation is continued for 4-6 hours. The residual li(iuid is purified by a procedure similar to the one described for I lie ethyl ester. The yield of dimethyl cw-A -tetrahydrophthal-ule, boiling at 120 122"/5 mm., nf 1.4700, is 239 g. (80%). 

N 8.80% crysts (from ale), mp 78.5—79° sol in benz, toluene, dioxane acetone insol in w benzin. Its prepn was patented by C.J. Mighton [USP 2365717(1944) CA 39, 4627(1945)] thru heating of maleic acid anhydride 2-nitro-2-methyl-l-propanol in the presence of p-toluenesulfonic acid (Ref 2) It was found to be a suitable plasticizer of NC when It was desired to obtain flexihle solvendess rolled sheet propellants (Ref 3) Refs . 1) Beil 2, 19251 [Di( methylpropyl) maleate] 2) Beil 2, ]l925i [Di( 2-nitro-2-methylpropyl)-maleate] 3) Anon, Summary-TechRept of Div 8, NDRC, Vol -1(1946), pi 19... 

Succinic anhydride and p-toluenesulfonic acid monohydrate were purchased from Wako Pure Chemical Industries, Ltd. (Japan). Guaranteed-grade t-(-)-menthol was purchased from Tokyo Kasei Kogyo Company, Ltd. (Japan). Reagent-grade toluene was dried and stored over sodium metal. The checkers obtained p-toluenesulfonic acid from Eastman Kodak, and succinic anhydride and t-(-)-menthol from the Aldrich Chemical Company, Inc. 

A mixture of phthalic acid anhydride (40 mmol), A, A, 2-trimethylpropane-l,3-diamine (4.6 g, 40 mmol), and a catalytic amount of p-toluenesulfonic acid in toluene (100 mL) was refluxed using a water separator. After a reaction time of 4 h, the solvent was evaporated. The oily residues were purified by means of column chromatography (silica gel, eluent CH2Cl2 MeOH = 1 1). The obtained oils crystallized after a few hours at room temperature and the product was obtained at 64% yield. 

To a flask equipped with a condenser were added 10 mL dry toluene, 3.0 mmol acetic anhydride, 0.15 mL dimethyl maleate (1.27 mmol), and a catalytic amount of p-toluenesulfonic acid. Under argon, 100 mg 2,6-dichloro-4-[(phenyl-sulflnyl)methyl]nicotinaldehyde (0.32 mmol) in toluene was added to above solution, dropwise over a period of 10 min. After the addition was complete, the yellow mixture was refluxed for an additional hour. The reddish yellow solution was cooled and washed with saturated aqueous NaHC03 solution. The organic layer was concentrated and purified by preparative layer chromatography to give dimethyl l,3-dichloro-5-(phenylthio)isoquinoline-6,7-dicarboxylate, in a yield of 44% yield, m.p. 109-111°C. 

Thorium Nitrate Thorium Nitrate Trichloroethylene T riisobuty laluminum T riisobutylaluminum Tetrabutyl Titanate Tetrabutyl Titanate Titanium Tetrachloride Toluene Toluene 2,4-Diisocyanate (TDI) Toluene 2,4-Diisocyanate (TDI) P-Toluene ulfonic Acid O-Toluidine Toluene Toluene 2,4-Diisocyanate (TDI) Toluene 2,4-Diisocyanate (TDI) Cresyl Glycidyl Ether Cresyl Glycidyl Ether P-Toluenesulfonic Acid Toxaphene Chloroane Maleic Acid Maleic Anhydride Oil Transformer Oil Motor Oil Lubricating Trifluralin Trichloroethylene Trichloroethylene Benzene Hexachloride Calcium Arsenate Calcium Arsenate... 

Trichlorosilane Chloropicrin, Liquid Vanadium Oxytrichloride Toluene 2,4-Diisocyanate (TDI) Toluene 2,4-Diisocyanate (TDI) Cresyl Glycidyl Ether Cresyl Glycidyl Ether P-Toluenesulfonic Acid Toxaphene Chloroane Maleic Acid Maleic Anhydride Oil Transformer... 

Benzoic anhydride treated with a little ZnGl2 then dropwise with 0.625 mole a,a-dichloro-dimethyl ether, and heated 2 hrs. at 70-100° benzoyl chloride. Y 98%.—Similarly from p-toluenesulfonic acid monohydrate with 2.5 moles a,a-dichlorodimethyl ether p-toluene-sulfonyl chloride. Y 92,5%. F. e., also from carboxylic acids and alkali carboxylates, s. A. Rieche and H. Gross, B. 92, 83 (1959). 

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