Lab 6: Electrophilic Aromatic Substitution
Lab 6: Electrophilic Aromatic Substitution(1) Nitration of Methyl Benzoate(2) Synthesis of 1,4-Di-t-butyl-2,5-dimethoxybenzene byFriedel-Crafts Alkylation of 1,4-DimethoxybenzenePurpose1)To carry out the nitration of methyl benzoate, and then identify the major product formed (position at which nitro-group substitution takes place) by thin-layer chromatography (TLC), the percent yield and the melting point range.
2)To synthesize 1,4-Di-t-butyl-2,5-dimethoxybenzene by Friedel-Crafts Alkylation of 1,4-Dimethoxybenzene, and then determine the percent yield and melting point range.
Procedure*Please refer to the lab handout 6 and Macroscale and Microscale Organic Experiments (Williamson, 2003).
* Part II of the experiment (Synthesis of 1,4-Di-t-butyl-2,5-dimethoxybenzene by Friedel-Crafts Alkylation of 1,4-Dimethoxybenzene) was carried out by Ashley and me. Part I (nitration of methyl benzoate) was carried out by Jenny.
Physical Quantity TableType of substanceMolecular FormulaMolecular Weight (g/mol)Density(g/cm3)M.P.(oC)B.P.(oC)Methyl benzoateC8H8O2136.161.094-15198-200Methyl 2-nitrobenzoateC8H7NO4181.141.289-13104Methyl 3-nitrobenzoateC8H7NO4181.14-78-80289Methyl 3,5-dinitrobenzoateC8H6N2O6226.14544-106-109-Methyl 4-nitrobenzoateC8H7NO4181.15-94-96-1,4-DimethoxybenzeneC8H10O2138.161.0555-582131,4-Di-t-butyl-2,5-dimethoxybenzeneC16H26O2250.37-104-105-2-methyl-2-propanolC4H10O74.12-25.482.4Hazard Concentrated sulfuric acid and nitric acid are highly corrosive.
ObservationPart II Friedel-Crafts AlkylationThe concentrated sulfuric acid used was yellow. 1,4-Dimethoxybenzene was in white crystal form. The t-butyl alcohol solidified in room temperature, so it took a while to heat it up and return to liquid form. After concentrated sulfuric acid was added to the t-butyl alcohol, acetic acid and 1,4-Dimethoxybenzene mixture, the solution became light brown in color. After warming for a while, white precipitate could be observed at the bottom of the tube. After water was
2)To synthesize 1,4-Di-t-butyl-2,5-dimethoxybenzene by Friedel-Crafts Alkylation of 1,4-Dimethoxybenzene, and then determine the percent yield and melting point range.
Procedure*Please refer to the lab handout 6 and Macroscale and Microscale Organic Experiments (Williamson, 2003).
* Part II of the experiment (Synthesis of 1,4-Di-t-butyl-2,5-dimethoxybenzene by Friedel-Crafts Alkylation of 1,4-Dimethoxybenzene) was carried out by Ashley and me. Part I (nitration of methyl benzoate) was carried out by Jenny.
Physical Quantity TableType of substanceMolecular FormulaMolecular Weight (g/mol)Density(g/cm3)M.P.(oC)B.P.(oC)Methyl benzoateC8H8O2136.161.094-15198-200Methyl 2-nitrobenzoateC8H7NO4181.141.289-13104Methyl 3-nitrobenzoateC8H7NO4181.14-78-80289Methyl 3,5-dinitrobenzoateC8H6N2O6226.14544-106-109-Methyl 4-nitrobenzoateC8H7NO4181.15-94-96-1,4-DimethoxybenzeneC8H10O2138.161.0555-582131,4-Di-t-butyl-2,5-dimethoxybenzeneC16H26O2250.37-104-105-2-methyl-2-propanolC4H10O74.12-25.482.4Hazard Concentrated sulfuric acid and nitric acid are highly corrosive.
ObservationPart II Friedel-Crafts AlkylationThe concentrated sulfuric acid used was yellow. 1,4-Dimethoxybenzene was in white crystal form. The t-butyl alcohol solidified in room temperature, so it took a while to heat it up and return to liquid form. After concentrated sulfuric acid was added to the t-butyl alcohol, acetic acid and 1,4-Dimethoxybenzene mixture, the solution became light brown in color. After warming for a while, white precipitate could be observed at the bottom of the tube. After water was
References: )Williamson, Macroscale and Microscale Organic Experiments, 4th Edition, 2003, Chapter 28 & 29, P. 367 - 3852)Solomons and Fryhle, Organic Chemistry, 8th edition, 2004, P. 669 - 680