Grignard Synthesis of Triphenylmethanol Lab Report
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 covalent. The ionic bonded compounds (example: RNa) have a weak bond between the carbon and the metal, and are therefore not useful because they are so volatile, and they will react with nearly anything. The covalent bonded compounds (example: R2Pb) are toxic. The compounds that are polar covalent bonded are Grignard reagents and are useful in making carbon-carbon bonds and reducing carbonyls.
Grignard reagents are any of the numerous organic derivatives of magnesium (Mg), commonly represented by the general formula RMgX (in which R is a hydrocarbon radical: CH3, C2H5, C6H5, etc.; and X is a halogen atom, usually chlorine, bromine, or iodine). They are called Grignard reagents after their discoverer, French chemist Victor Grignard, who was a corecipient of the 1912 Nobel Prize for Chemistry for this work (1).
Grignard reagents commonly are prepared by reaction of an alkyl halide (RX) with magnesium in a nitrogen atmosphere because the reagent is very reactive toward oxygen and moisture, which would cause the reagent to react with the water instead of any carbon atoms (2). Grignard reagents react with water to produce alkanes. This is the reason that everything has to be very dry during the preparation.
Alkyl halides vary
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 covalent. The ionic bonded compounds (example: RNa) have a weak bond between the carbon and the metal, and are therefore not useful because they are so volatile, and they will react with nearly anything. The covalent bonded compounds (example: R2Pb) are toxic. The compounds that are polar covalent bonded are Grignard reagents and are useful in making carbon-carbon bonds and reducing carbonyls.
Grignard reagents are any of the numerous organic derivatives of magnesium (Mg), commonly represented by the general formula RMgX (in which R is a hydrocarbon radical: CH3, C2H5, C6H5, etc.; and X is a halogen atom, usually chlorine, bromine, or iodine). They are called Grignard reagents after their discoverer, French chemist Victor Grignard, who was a corecipient of the 1912 Nobel Prize for Chemistry for this work (1).
Grignard reagents commonly are prepared by reaction of an alkyl halide (RX) with magnesium in a nitrogen atmosphere because the reagent is very reactive toward oxygen and moisture, which would cause the reagent to react with the water instead of any carbon atoms (2). Grignard reagents react with water to produce alkanes. This is the reason that everything has to be very dry during the preparation.
Alkyl halides vary
References: 1. Carey, Francis A. "Grignard Reagent." Encyclopedia Britannica Online. Encyclopedia Britannica, 2012. Web. 12 Mar. 2012. <http://www.britannica.com/EBchecked/topic/246137/Grignard-reagent>. 2. "Grignard Reagents." Chemguide: Helping You to Understand Chemistry. 2012. Web. 12 Mar. 2012. <http://www.chemguide.co.uk/organicprops/haloalkanes/grignard.html>. 3. "Setup of Reflux Apparatus." 10 Apr. 2011. Web. 12 Mar. 2012. <http://www.chem.ucla.edu/~bacher/Specialtopics/reflux.html>. 10. Iodine; ICSC No. 0167 (U.S. National Version) [Online]; National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention: Atlanta, GA, 2001. http://www.cdc.gov/niosh/ipcsneng/neng0270.html (accessed March 12, 2012). 11. "Triphenylmethanol." Material Safety Data Sheet. J.T. Baker, 17 Nov. 1999. Web. 13 Mar. 2012. <https://go.dmacc.edu/chemistry/safety/Documents/Triphenylmethanol.pdf>. 12. Kelly, William. "Grignard Reaction." Organic II Laboratory. Web. 13 Mar. 2012.