Methyl-6-methylheptanoate

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: 2 g concentrated sulfuric acid were added to a solution of 32 g (1 mol) methanol and 144 g (1 mol) "isooctanoic acid" (isomeric mixture from Ruhrchemie A. G. Oberhausen) in 200 ml toluene and heated to boiling with hater separation until the equimolar amount of water separates (about 2 hours). After cooling it was washed with water and then with 10% sodium bicarbonate solution. The solvent was distilled off under reduced pressure. The remaining end-product after distillation over a 15 cm Vigreux column gave 150 g (95%) isooctanoic acid methylester as an easily mobile liquid with a fruity smell. heated to boiling with hater separation until the equimolar amount of water (about 2 hours) After cooling it was washed with water The solvent was distilled off under reduced pressure The remaining end-product after distillation over a 15 cm Vigreux column

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A dispersion of 16.9 G (0.4 mole) of 56% by weight sodium hydride in mineral oil is slurried with n-pentane under nitrogen, the supernatant liquid is removed by suction with a sintered glass tip tube. This process is repeated three times before 500 ml of dry tetrahydrofuran and 75.8 G (0.48 mole) of methyl isooctanoate are added. The resultant mixture is heated to reflux temperature with agitation. A total of 48 G (0.4 mole) of acetophenone is added to the above refluxing mixture over a 3 hour period of time. The system is maintained at reflux temperature for an additional one half hour after the acetophenone addition is completed. Approximately 20 ml of methanol is added to the above mixture at room temperature to destroy any unreacted sodium hydride. The reaction mixture is then poured into a vigorously stirred mixture of 75 ml of concentrated hydrochloric acid and 250 G of ice. When most of the ice has melted the solution is extracted twice with 242 ml of heptane per extraction. The combined heptane extracts are successively washed with water, 10% sodium carbonate solution and again with water. The heptane solution is dried with sodium sulfate, filtered, the volatiles removed at reduced pressure and the residue distilled to yield 1-phenylisodecane-1,3-dione. the supernatant liquid is removed by suction with a sintered glass tip tube are added to reflux temperature with agitation The system is maintained at reflux temperature for an additional one half hour to destroy any unreacted sodium hydride The reaction mixture is then poured into a vigorously stirred mixture of 75 ml of concentrated hydrochloric acid and 250 G of ice is extracted twice with 242 ml of heptane per extraction The combined heptane extracts are successively washed with water, 10% sodium carbonate solution and again with water The heptane solution is dried with sodium sulfate filtered the volatiles removed at reduced pressure the residue distilled

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: The sulfuric acid is employed in an amount sufficient to both catalyze the reaction and to serve as a dehydrating agent or desiccant for the by-product water. Accordingly, the sulfuric acid should be employed in an amount greater than about 0.05 moles per mole of carboxylic acid to be esterified and preferably above 0.1 moles and of sulfuric acid per mole of carboxylic acid, which is sufficient to both catalyze the dehydrate the water. Most desirably, from about 0.1 to about 0.5 moles of sulfuric acid and most preferably about 0.2 moles will be employed per mol of carboxylic acid. The reaction is carried out at elevated temperatures, conveniently reflux conditions. With methanol as the alcohol and a carboxylic acid having from about 6 to about 22 carbon atoms a temperature will be on the order of about 70° to about 100° C. However, temperatures on the order at about 40° to about 120° C. and more preferably 60° to about 80° C. will be employed. The specific temperature employed will be determined however by the specific alcohol employed and specific carboxylic acid to be esterified. In the laboratory reflux periods of about 1 to 2 hours were sufficient to provide yields of methyl isooctanoate in the methanol esterification of isooctanoic acid employing about 1.5 to about 2 moles of methanol per mole of isooctanoic acid which provided the ester of greater than 99% purity. In contrast, in reactions not using an excess of sulfuric acid (only a catalytic amount) time periods of reflux of about 10 hours or more were required to provide about an 80% yield of ester of lower purity even with a seven molar excess of methanol. Again, the reaction period will depend on the specific alcohol employed and specific acid to be esterified. Generally reaction periods will not need to exceed about 4 hours and the reaction will be complete (about 90% yield) usually within 1 to about 3 hours employing the preferred levels of carboxylic acid, alcohol and sulfuric acid. After completion of the esterification the sulfuric acid layer is removed and any unesterified acid is removed as the sodium salt by an alkaline aqueous wash. The ester may be dried by azeotropic distillation with an aliphatic hydrocarbon solvent such as heptane. The unreacted carboxylic acid in the aqueous alkaline wash can be recovered by acidification with an acid, preferably spent sulfuric acid, from the esterification step. the reaction will be on the order of about 70° to about 100° C at about 40° to about 120° C. more preferably 60° to about 80° C. In the laboratory reflux periods of about 1 to 2 hours to provide

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: 2 g concentrated sulfuric acid were added to a solution of 32 g (1 mol) methanol and 144 g (1 mol) "isooctanoic acid" (isomeric mixture from Ruhrchemie A. G. Oberhausen) in 200 ml toluene and heated to boiling with hater separation until the equimolar amount of water separates (about 2 hours). After cooling it was washed with water and then with 10% sodium bicarbonate solution. The solvent was distilled off under reduced pressure. The remaining end-product after distillation over a 15 cm Vigreux column gave 150 g (95%) isooctanoic acid methylester as an easily mobile liquid with a fruity smell. heated to boiling with hater separation until the equimolar amount of water (about 2 hours) After cooling it was washed with water The solvent was distilled off under reduced pressure The remaining end-product after distillation over a 15 cm Vigreux column