Grignard Synthesis of Triphenylmethanol from Benzophenone

Grignard Synthesis of Triphenylmethanol from Benzophenone Purpose: The purpose of this experiment was to synthesize the tertiary alcohol triphenylmethanol from a Grignard reagent, phenyl magnesium bromide. The Grignard reagent was synthesized from bromobenzene and magnesium and then reacted with benzophenone to produce triphenylmethanol. It was important that water be excluded from the reaction, in order to prevent the formation of benzene. The reaction of phenyl magnesium bromide and benzophenone was quenched with sulfuric acid, and an extraction was performed in order to separate the organic phase containing the triphenylmethanol from the aqueous phase. The triphenlmethanol was then isolated and purified by crystallization and†¦show more content†¦The magnesium and bromobenzene mixture in the flask did not become cloudy, even after the addition of a crystal of iodine. On the second attempt at synthesizing the Grignard, after adding a crystal of iodine to start the reaction, the mixture in the flask did begin to grow cloudy a nd small bubbles arose from the surface of the magnesium, indicating the start of the reaction. As the reaction progressed, the flask became increasingly cloudy and was slightly brownish in color from the iodine. Some bits of magnesium still remained at the bottom of the flask after about half an hour or 45 minutes, indicating that the Grignard reaction was not complete, but the benzophenone was added anyway due to time constraints. The solution became bright pink and after several minutes of swirling the flask at room temperature, it became a whitish pink color. The solution also became a thicker consistency, though it appeared to still be liquid for the most part. Because of this thick consistency, some of the product may have been lost when poured into the sulfuric acid/ice water solution, even with the addition of ether to try to rinse it out from the flask. After performing the extraction and washes, the triphenylmethanol, biphenyl, and ether solution appeared to be a clea r yellowish liquid. In performing the crystallization in the hood,Show MoreRelatedGrignard Reaction1125 Words   |  5 PagesLab #5: Grignard Reaction – Synthesis of Triphenylmethanol John Kang Chem 152L Performed: 7/20/04 Date submitted: ________________ Lab Partners: Sang Lee, Vicky Lai TA: John Stanko Abstract: This experiment explored the synthesis of triphenylmethanol through the use of Grignard reagents. The percent yield of the product was 10% on a relatively humid day. The melting point was calculate to be 127.2oC with a literature value of 162oC. An IR spectrum of the product was taken and usedRead MoreThe Grignard Synthesis of Triphenylmethanol3162 Words   |  13 Pagespurpose of this lab was to synthesize triphenylmethanol from benzophenone and bromobenzene by the formation of a Grignard compound with the reagents bromobenzene and magnesium metal. The bromobenzene was first transformed into the Grignard compound and was then reacted with the benzophenone to make the final product. The mixture was then mixed with sulfuric acid and the organic layer was extracted via a separatory funnel. The mixture was then recrystallized from methanol and was allowed to dry andRead MoreGrignard Synthesis of Triphenylmethanol Lab Report Essay5146 Words   |  21 PagesThe Grignard Synthesis of Triphenylmethanol Organic Chemistry Lab II March 19, 2012 Abstract The purpose of this experiment was to synthesize the Grignard reagent, phenyl magnesium bromide, and then use the manufactured Grignard reagent to synthesize the alcohol, triphenylmethanol, by reacting with benzophenone and protonation by H3O+. The triphenylmethanol was purified by recrystallization. The melting point, Infrared Spectroscopy, 13C NMR, and 1H NMR were used to characterize and confirmRead MoreOrganic 2 Lab Report6389 Words   |  26 Pagesspectroscopy. The unknown ketone is from a homologous series of methyl ketones. CH3CO (CH2) nCH3 The first step in the lab is the preparation of the solvent used in the developing chamber for thin layer chromatography. The solvent used is a 3:1 mixture of toluene and petroleum. After the developing chamber is prepared, it is essential to begin preparation of the unknown DNPH derivative[6]. The preparation of the 1,2 DNPH derivative of a ketone is in fact a small organic synthesis which produces a fraction