Diels-Alder Lab Report

Friedal-Crafts Alkylation: Synthesis of 1,4-di-t-butyl-2,5-dimethyloxybenzene

Reaction:

Data Table:

Molecular Weight | Amount Used | Molecular Formula | Density | Melting Point | Total Moles |

Chemical Name | | | | | | |

*1,4 dimethoxybenzene | 138.16 g/mol | 1.0 g | C8H10O2 | 1.053 g/ml | 54˚C-56˚C | .007238 |

*Tert-Butanol | 74.12 g/mol | 2 ml | C4H10O | .81 g/ml | 25˚C- 26˚C | .021856 |

*Glacial Acetic Acid | 60.05 g/mol | 3 ml | C2H4O2 | 3.24 g/ml | | |

*Sulfuric Acid | 98.08 g/mol | 5 ml | H2O4S | 1.84 g/ml | | |

*Water | 18 g/mol | 25 ml | H2O | 1.0 g/ml | | |

*Methanol | 32.04 g/mol | 30 ml | CH4O | .791 g/ml | | |

Product | MolecularFormula | Moleculer Weight | Theoretical Yield | Actual Yield | PercentYield | Melting Point |

41,4-di-t-butyl-2,5-dimethoxybenzene | C16H26O2 | 250.38 g/mol | 1.8 g | .982 g | 56% | (97˚C-100˚C)(*102˚C-104˚C) |

IR Peak Results:

Peak | Functional Group |

3366 | O-H Alcohol |

2992 | Sp3 C-H |

2961 | Sp3 C-H |

2865 | Sp3 C-H |

Discussion:

Alkylation of benzene with alkyl halides in the presence of aluminum chloride was discovered by Charles Friedel and James M. Crafts in 1877. They developed the Friedel-Crafts reaction into one of the most synthetic methods in organic chemistry 1. The Friedel-Crafts reaction usually involves treating benzene with a secondary or tertiary alkyl halide and a Lewis acid 2. The purpose of this experiment is to synthesize 1,4-di-t-butyl-2,5-dimethoxybenzene from 1,4-dimethyoxybenzene with the addition of 2 tert-butyl groups. This Friedel-Crafts reaction was done using Electrophilic Aromatic Substitution via generating the carbocation electrophile by reacting 2 tertiary butyl alcohol groups with sulfuric acid 3.

The reaction began with 1.0 g of 1,4-dimethoxybenzene, 2 ml of tert-butanol, and 3 ml of glacial acetic acid being added to a 125 ml Erlenmeyer flask. The mixture was then swirled and...