OCHEM 2 Special Projects Sulfanilamide

OCHEM 2 Special Projects Sulfanilamide - Special Projects:...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Special Projects: The Synthesis of Sulfanilamide Lindy Hilpert Chemistry 0340 Aaron Crandall April 9, 2008
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Introduction The purpose of this experiment was to synthesize sulfanilamide through the intermediates of acetanilide, p-acetamidobenzenesulfonyl chloride, and p- acetamidobenzene sulfonamide, respectively over three weeks. The products were characterized and verified using IR, H-NMR, and C-13 NMR spectra. Theory Electrophilic aromatic substitution (EAS) is an organic reaction. It involves a hydrogen on an aromatic being replaced by an electrophile. The electron-rich (nucleophilic) aromatic is attacked by the electron-poor (electrophilic) electrophile. This leads to the creation of a carbocation also called an arenium ion. The arenium ion is unstable due to the loss of aromaticity and the positive charge. There is slight stability due to the resonance of the positive charge over three carbons. A Lewis base then comes in and donates electrons to the hydrogen that is attached to the same carbon as the electrophile. This process reforms the double bond and restores the aromaticity. The most common types of EAS are halogenation, nitration, sulfonation, Friedel-Crafts alkylation, and Friedel-Crafts acylation. When dealing with EAS, substituents on the aromatic can be activating or deactivating. Activating means that the substituent makes the molecule more reactive, thus making it more likely to add another substituent. Activators are ortho/para directing, which means that they direct another substitution to the ortho and para positions. The ortho position is the carbon directly next to the carbon to which the deactivating substituent is attached. The para position is the carbon three carbons away from the carbon to which the deactivating substituent is attached. Activators are also called donors because they donate electrons to the aromatic ring through induction and resonance, making it more nucleophilic. Examples of activating groups are alkyl groups, oxygen groups, amino groups, and amides. Deactivating means that the substituent makes the molecule less reactive, thus making it less likely to add another substituent. Deactivators are meta directing which means that they will direct another substitution to the meta position. The meta position is the carbon two carbons away from the carbon to which the activating substituent is attached. Deactivators are also called acceptors because they remove electron density from the aromatic ring, making it less nucelophilic.
Background image of page 2
Deactivators are also called acceptors because they accept electrons. Examples of deactivating groups are NO2, CF3, CN, CO2H, and carboxyl groups. Protecting groups can be used in order to ensure that a substituent on a ring is added in the correct place. A protecting group is a substituent that protects the site at which it is attached and can be removed easily. They are added into the reaction to occupy a certain site so that another substituent cannot be added there. They can also be
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This lab report was uploaded on 04/07/2008 for the course CHEM 0340 taught by Professor Crandall during the Fall '07 term at Pittsburgh.

Page1 / 16

OCHEM 2 Special Projects Sulfanilamide - Special Projects:...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online