Grignard Synthesis of Triphenylmethanol Lab Report Essay

The 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 confirm the recrystallized substance was triphenylmethanol. Introduction A Grignard reagent is a type of organometallic, which consists of a bond between a metal and a carbon. There are three types of carbon-metal bonds: ionic, polar covalent, and†¦show more content†¦Grignard reagents also react with the least hindered carbon on an epoxide to break the ring in order to relieve ring strain. A reaction of the Grignard reagent and carbon dioxide results in an acid, and reaction of a nitrile and a Grignard reagent produce a carbonyl via an imine intermediate. These are show below, respectively. Grignard reagents are reactive enough to also attach esters; however, two equivalents of the Grignard reagent are usually added because less then two equivalents leave a large quantity of unreactive ester. This reaction forms a tertiary alcohol. Grignard reagents cannot be synthesized from alcohols because instead of reacting with the halide to form the Grignard reagent, the alcohol is deprotenated. Grignard reagents also cannot be synthesized from molecules with a carbonyl group. Solvent choice is important in Grignard reagent formation. The solvent must be non-reactive with a negatively charged carbon (ex. acetone or anything even slightly acidic), and the solvent cannot have a carbonyl group. The solvent must be a volatile solvent that provides a blanket of solvent over the reaction solution so that oxygen and moisture in the air are excluded from the reaction. Oxygen and moisture in the air are very slightly acidic and would disrupt the synthesis of a Grignard reagent. Anhydrous ether (R2O) is often used as a solvent in creating Grignard reagents because it keeps out water and oxygen, makes theShow 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 MoreOrganic 2 Lab Report6389 Words   |  26 PagesnCH3 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 of a gram of product. The second part of the lab makes use of NMR Spectrometry