Notice: Concentration information is not available for this spectrum and, therefore, molar absorptivity values cannot be derived. Measure 120 mg of 1,4-dimethoxybenzene, 0. So the options are really the 1-3 and the 1-4 product. When all the sulfuric acid was added, the mixture was stirred at room temperature for 10 minutes. The complete molecule is generated by the application of a crystallographic centre of inversion.
By adhering to this procedure, it would likely reduce both the amount of impurities present within the supplied chemicals, and also aid in the recovery of the product. The product, 1,4-di- tert-butyl-2,5-dimethoxybenzene, I , has also been reported to exhibit a dramatic change of shape during crystal growth Blatchly and Hartshorne, 1966. If the steam valve is turned off before the trap is opened, the steam in the trap will condense, creating a partial vacuum that will suck liquid from the flask into the trap and up the hose to the steam valve. As you are adding tert-butyl groups, putting 2 of those together is going to be sterically unfavorable 2,3 di tert butyl product because the central tert-butyl carbon is stuck in the plane with the sp hybridized carbons. The ethyl chains of two tert-pentyl groups stand to one side of the benzene plane in an anti-orientation, where the dihedral angle is 83. Select a region with no data or click the mouse on the plot to revert to the orginal display. The Friedel-Crafts alkylation of 1,4-dimethoxybenzene with tert-butyl alcohol is a popular introductory organic laboratory experiment to illustrate the features of electrophilic aromatic substitution Williamson et al.
These results are slightly problematic for two reasons; the actual percentage yield which is actually greater than the theoretical percentage yield of 21. Through this process a product of 56. Gently warm the solution within the reaction tube, it may be necessary to agitate the solution with a glass stirring rod and add the 0. Allow the reaction product to dry completely and then determine percent yield and melting point. Dry ice, solid carbon dioxide, sublimes to the gas without melting. Secretary of Commerce on behalf of the United States of America.
The crystal packing exhibits a herringbone structure. To apply the reaction of Friedel-Crafts Alkylation to dimethoxybenzene Chemical Index: Chemical Structure Molecular Weight Melting Point Boiling Point Acetic Acid C2H4O2 60. Although the product was allowed to dry for a couple days, it was never washed with a solvent such as methanol to reduce the impurities within the product. Therefore, this liquid rich in the high boiling component must return to the flask for maximum separation of a mixture. So, the second alkylation will be favored ortho to the alkyl group, instead of meta to it. This descending liquid, in a slow and careful distillation, is in equilibrium with ascending vapor.
The title compound, C 18H 30O 2, was prepared by Friedel—Crafts alkylation of 1,4-dimethoxybenzene with 2-methyl-2-butanol. The plate was removed from the developing chamber, the residual solvent was allowed to evaporate from the plate, and then the plate was returned to the developing chamber. The polymer is a macromolecular analogue of the well known redox shuttle 2,5-di- t-butyl-1,4-dimethoxybenzene. Any solid that has a strong odor is subliming; for example, moth balls p-dichlorobenzene or, formerly, naphthalene. The deviations in results both of the actual percentage yield vs. If the trap is partially opened, this process will create a siphon that will siphon all of the liquid in the flask down the drain.
Stir the mixture thoroughly with a glass stirring rod, remove reaction tube from ice bath and allow the solution to reach room temperature approximately 15 minutes. The methoxy groups are inclined at 33. The second alkylation can either go on the same side as the first, or on the opposite side, making 3 possible products. In contrast to I , the methoxy groups lie on almost the same plane as the benzene ring, where the dihedral angle is 4. Concentrated sulfuric acid 5 ml was added dropwise into the vigorously stirred reaction mixture so as not to exceed the temperature of 283 K. Lack of complete reaction will leave unreacted n-butyl alcohol, dehydration will give 1-butene, and a competing reaction will give di-n-butyl ether.
Macroscale and Microscale Organic Experiments, 5th ed. The water that evaporates is collected on a very cold surface in order to maintain the high vacuum. Clothes can be hung out to dry even when the temperature is below 0°C. Select a region with data to zoom. Cool the solution in an ice bath, once the solution is sufficiently cooled, place the reaction tube containing the solution within the fume-hood and add 0. For instance, the melting point determined through this lab was 71. The white solid was filtered off on a small Büchner funnel and washed with a small amount of ice-cold ethanol.
A distillation in progress can, of course, be sealed from the atmosphere because no vapor should escape from the apparatus. To understand the general process, reaction and limitations of Friedel-Crafts Alkylation in regards to Dimethoxybenzene 2. The food will freeze without external application of cold as the first water evaporates because of the high heat of vaporization of water. If this experiment were to be repeated in order to compare the results to the previously conducted experiment, it would be suggested that the procedure explicitly adhere to the procedure outlined by the text book, Macroscale and Microscale Organic Experiments 6th Edition by Kenneth L. The major flaw in the process occurred when the product was extracted from the reaction tube, although the tube was rinsed twice with water it is almost impossible to transport the entirety of the crystal product. References Go To: , , Data compilation by the U. In a 10X100 mm reaction tube, dissolve the120 mg of 1,4-dimethoxybenzene in the 0.
Related literature For the synthesis of the title compound, see: Polito et al. Since the ethyl chain and methyl group of tert-pentyl group and methoxy group are aggregated by hydrophobic interactions, each molecule is closely arranged in the brick-wall fashion Fig. Comment Electrophilic aromatic substitution is one of the key reactions in organic chemistry. After the addition of 0. This work was partially supported by a Grant-in-Aid for Young Scientists B grant No. In the crystal, the hydrophobic molecules pack to form a brick-wall-like architecture. There is no particular difference with the first alkylation product.