Question

Draw the condensed structures of the compounds formed from (a) butanoic acid and methanol, ( b) benzoic acid and 2-propanol, (c) propanoic acid and dimethylamine. Name the compound in each case.

Short answer

The condensed structures and names of the compounds formed from the given reactions are: (a) Butanoic acid and methanol: Product: Methyl butanoate, CH3CH2CH2COOCH3 (b) Benzoic acid and 2-propanol: Product: Isopropyl benzoate, C6H5COOCH(CH3)2 (c) Propanoic acid and dimethylamine: Product: N,N-dimethylpropanamide, CH3CH2CON(CH3)2

Step-by-step solution

(a) Butanoic acid and methanol reaction

1. Identify reactants and product type: Butanoic acid and methanol are reacting together to form an ester. 2. Draw the structures of the reactants: - Butanoic acid: CH3CH2CH2COOH - Methanol: CH3OH 3. Connect reactants to form the ester: The ester is formed by the reaction of the carboxylic acid and the alcohol, with the loss of water. The oxygen of the alcohol connects to the carbonyl carbon of the carboxylic acid. 4. Draw the condensed structure of the product: The product formed is CH3CH2CH2COOCH3 5. Name the compound: The IUPAC name for this compound is methyl butanoate.

(b) Benzoic acid and 2-propanol reaction

1. Identify reactants and product type: Benzoic acid and 2-propanol are reacting together to form an ester. 2. Draw the structures of the reactants: - Benzoic acid: C6H5COOH - 2-propanol: CH3CHOHCH3 3. Connect reactants to form the ester: The ester is formed by the reaction of the carboxylic acid and the alcohol, with the loss of water. The oxygen of the alcohol connects to the carbonyl carbon of the carboxylic acid. 4. Draw the condensed structure of the product: The product formed is C6H5COOCH(CH3)2 5. Name the compound: The IUPAC name for this compound is isopropyl benzoate.

(c) Propanoic acid and dimethylamine reaction

1. Identify reactants and product type: Propanoic acid and dimethylamine are reacting together to form an amide. 2. Draw the structures of the reactants: - Propanoic acid: CH3CH2COOH - Dimethylamine: (CH3)2NH 3. Connect reactants to form the amide: The amide is formed by the reaction of the carboxylic acid and the amine, with the loss of water. The nitrogen of the amine connects to the carbonyl carbon of the carboxylic acid. 4. Draw the condensed structure of the product: The product formed is CH3CH2CON(CH3)2 5. Name the compound: The IUPAC name for this compound is N,N-dimethylpropanamide.

Key concepts

Condensed Structural Formulas

Condensed structural formulas provide a simplified representation of molecular structures. They string together atoms in the order they appear, somewhat reflecting the actual sequence in the molecule, but without pictorially showing the bonds. This makes them efficient for quickly conveying molecule information.

• In an esterification reaction like that between butanoic acid and methanol, the condensed structural formula CH3CH2CH2COOCH3 tells us about the molecular structure of the product, methyl butanoate.
• Condensed formulas are helpful for visualizing complex molecules quickly, as in the product C6H5COOCH(CH3)2 from benzoic acid and 2-propanol, showing the ester linkage clearly.
• When propanoic acid reacts with dimethylamine, an amide is formed with a condensed structure of CH3CH2CON(CH3)2, illustrating the attachment of the nitrogen group to the carbon chain.

Understanding condensed structural formulas assists in visualizing and predicting molecular behaviors.

IUPAC Nomenclature

IUPAC nomenclature provides a standardized method to name chemical compounds, ensuring clarity and universality in scientific communication. This system assigns names based on the type of functional groups present, the number of carbon atoms, and the arrangement of atoms within the molecule.

• The ester formed from butanoic acid and methanol is named methyl butanoate. Here, 'methyl' indicates the alcohol-derived part (methanol), and 'butanoate' is derived from butanoic acid.
• For the reaction of benzoic acid and 2-propanol, the product is named isopropyl benzoate. 'Isopropyl' represents the alcohol portion (2-propanol), while 'benzoate' originates from benzoic acid.
• Propanoic acid and dimethylamine yield N,N-dimethylpropanamide. The prefix 'N,N-dimethyl' describes the substituents on the nitrogen atom, providing more detail in the naming.

An understanding of IUPAC nomenclature is essential for accurately identifying and communicating the structure of organic compounds.

Functional Groups in Organic Chemistry

Functional groups are specific groupings of atoms within molecules responsible for characteristic chemical reactions. They play a vital role in determining the properties and reactivity of organic compounds.

• An ester group forms when a carboxylic acid reacts with an alcohol, as seen in the formation of methyl butanoate and isopropyl benzoate. This group is typically represented by RCOOR', where R and R' are carbon-containing substituents.
• Amides arise from a reaction between a carboxylic acid and an amine, demonstrated in N,N-dimethylpropanamide. These groups are represented as RCONR'R'', where R, R', and R'' are carbon chains or hydrogens.

Recognizing these functional groups allows chemists to predict the behavior of compounds in chemical reactions, making them foundational elements in organic chemistry.