Grignard Reaction

Only available on StudyMode
  • Download(s) : 195
  • Published : May 6, 2012
Open Document
Text Preview
The purpose of this experiment was to synthesize triphenylmethanol from a Grignard reagent. The Grignard reaction technique was used in this synthesis but due to the fact that it is such a strong nucleophile and base, it was important to prevent water from interfering with the Grignard reaction. Purity of the product was determined by measuring the melting point.

Reagent Table:
Structure Name Molecular formula
Molar mass
Melting point
Boiling Point

Diethyl etherC4H10O74.12 g mol−0.7134 g/cm3, liquid-116.3 °C, 157 K, -177 °F
34.6 °C, 308 K, 94 °F

BromobenzeneC6H5Br157.01 g mol−11.495 g/cm³, liquid-30.8 °C (242.35 K)
156 °C (429.15 K)

Phenylmagnesium bromideC6H5MgBr181.31 g/mol1.14 g/cm3

BenzophenoneC13H10O182.217 g/mol1.11 g/cm3, solid47.9 °C
305.4 °C

TriphenylmethanolC19H16O260.33 g/mol1.199 g/cm3162 °C
360-380 °C

Anhydrous sodium sulfateNa2SO4142.04 g/mol2.664 g/cm3884 °C1429 °C

Petroleum etherC4H1087g/mol0.77 g/mL at 20 °C
90-100 °C

Isopropyl alcoholC3H8O60.1 g mol−10.786 g/cm3 (20 °C)
−89 °C, 184 K, -128 °F
82.5 °C, 356 K, 181 °F

Structure & Chemical Equations:
Step 1:
C6H5Br + Mg → C6H5Mg – Br
Step 2:
C6H5Mg – Br + (C6H5)2C = O → (C6H5)3C --- O-MgBr
Step 3:
(C6H5)3C --- O-MgBr → (C6H5)3C --- OH + Mg(OH)Br

The procedure that was conducted for the synthesis of triphenylmethanol from a Grignard reagent has been written in the pre lab notebook. This is where you can find the following instruction for this experiment. In the pre-lab notebook the experiment is explained in full details which will specify that there were no changes made to the experiment. Calculations:

Theoretical Yields:
1.094g benzophenone * (1 mol benzophenone/ 182.22 g benzophenone) = 0.006003732 mol benzophenone 0.006003732 mol benzophenone * (1 mol triphenylmethanol/1 mol benzophenone) * (260.33 g triphenylmethanol/ 1 mol...
tracking img