Vanadium oxyacetylacetonate

A solution of 21.3 g. (0.10 mole) of freshly distilled N,N-dimethyldodecylamine (Note 1), 9.6 g (0.10 mole) of 94% <-butyl hydroperoxide (Note 2), and 0.050 g. of vanadium oxyacetylacetonate (Note 3) in 27 g. (34 ml.) of Cbutyl alcohol is placed in a 250-ml. round-bottomed flask fitted with a. thermometer, a reflux condenser, and a heating mantle. The reaction mixture is heated to approximately 65-70°, at which point an exothermic reaction begins. The heating is discontinued until the vigorous exothermic reaction subsides (about 5 minutes) and then the reaction mixture is heated at reflux (the reaction mixture boils at 90°) for 25 minutes. After the resulting mixture has been cooled to room temperature, it is analyzed (Note 4) to establish the absence oft-butyl hydroperoxide, and then concentrated with a rotary evaporator (30-35° bath with 30-40 mm. pressure). The crude solid residue is triturated with 50 ml. of cold (0-5°), anhydrous diethyl ether and then filtered under conditions which prevent exposure of the residual amine oxide to atmospheric moisture (Note 5). The residual solid is washed with 50 ml. of cold (0-5°) anhydrous diethyl ether and then dried under reduced pressure to leave 12.9-15.5 g. of the crystalline amine oxide, m.p. 131-131.5°. Concentration of the mother liquors and trituration of the residual paste with 25 ml. of cold (0-5°) anhydrous diethyl ether separates another 4.9-3.4 g. of the amine oxide, m.]). 130-131°. The total yield of the crystalline amine oxide (Note 6) is 17.4-18.9 g. (76 83%). 

Vanadium oxyacetylacetonate may be purchased from Alfa Inorganics, Inc., Beverly, Massachusetts. 

Vanadium oxyacetylacetonate (Vanadyl acetylacetonate), VO(CH3COCH2COCH2)2 [1, 1271, before Vilsmeier reagent]. Mol. wt. 265.16, m.p. 255°, dec. Supplier Alfa Inorganics. 

DL-Valeric acid, 369 Vanadium oxyacetylacetonate, 456 Vanadyl acetylacetonate, see Vanadium oxyacetylacetonate Vanillin, 217 Veratrole, 116 a-Vetivone, 306 Vilsmeir reaction, 129 Vinylacetic acid, 428 crr-Vinylalanes, 141, 142 mww-Vinylalanes, 141, 142 Vinyl azides, 100 Vinyl halides, 142 Vinylidinebisdimethylamines, 400 Vinyl ketones, 71 Vinyllithium, 456 Vinylmagnesium halides, 91 Vinyl triphenylphosphonium bromide, 456-457... 

For an efficient procedure by Sheng and Zajacek for the oxidation of a tertiary amine to the amine oxide, see Vanadium oxyacetylacetonate (this volume). 

Silver iododibenzoate. Silver oxide. Sodium dichromate. Sodium persulfate. Thal-lium(III) trifluoroacetate. Trimethylamine oxide. Vanadium oxyacetylacetonate. 

Epoxidation.1 Cyclohexene epoxide can be prepared in quantitative yield by the reaction of cyclohexene with r-butyl hydroperoxide catalyzed by vanadium oxyacetylacetonate. 

Oxidation of aniline. Aniline is oxidized to nitrobenzene (39% conversion) by f-butyl hydroperoxide catalyzed by vanadium oxyacetylacetonate. Molybdenum compounds are somewhat less active tungsten and cobalt compounds are inactive.2... 

Vacuum manifold system, 51,56 Vanadium oxyacetylacetonate, 50,56 N-Vinylpyrrolidone, cyanation,50,54... 

Nitroalkanes and nitrocycloalkanes are convertible to ketones by potassium tert-butoxide and tm-butyl hydroperoxide in the presence of molybdenum hexacarbonyl or vanadium oxyacetylacetonate (Bartlett et al, 1977). Ketone, acetal, and ester functions are unaffected. 

---