Question

Write balanced equations, naming all organic products, for the following reactions: (a) n-butyryl chloride + methylamine (b) acetic anhydride \(+\mathrm{N}\) -methylaniline (c) tetra-n-propylammonium hydroxide + heat (d) tetramethylammonium hydroxide + heat (e) N,N-dimethylacetamide + boiling dilute \(\mathrm{HCl}\) (f) benzanilide + boiling aqueous \(\mathrm{NaOH}\) (g) \(\mathrm{m}-\mathrm{O}_{2} \mathrm{NC}_{6} \mathrm{H}_{4} \mathrm{NHCH}_{3}+\mathrm{NaNO}_{2}+\mathrm{H}_{2} \mathrm{SO}_{4}\) (h) \(\mathrm{m}\) -toluidine \(+\mathrm{Br}_{2}(\mathrm{aq})\) in excess (i) \(\mathrm{p}\) -toluidine \(+\mathrm{NaNO}_{2}+\mathrm{HCl}\) (1) \(\mathrm{p}-\mathrm{CH}_{3} \mathrm{C}_{6} \mathrm{H}_{4} \mathrm{NHCOCH}_{3}+\mathrm{HNO}_{3}+\mathrm{H}_{2} \mathrm{SO}_{4}\) (k) benzanilide \(+\mathrm{Br}_{2}+\mathrm{Fe}\)

Short answer

(f) Reaction of benzanilide with boiling aqueous NaOH Step 1: Write down the reactants and products Benzanilide (C13H11NO) reacts with boiling aqueous sodium hydroxide (NaOH) to produce aniline (C6H7N) and sodium benzoate (C6H5COONa). Step 2: Write the balanced equation C13H11NO + NaOH → C6H7N + C6H5COONa (g) Reaction of m-nitroaniline with NaNO₂ and H₂SO₄ Step 1: Write down the reactants and products m-Nitroaniline (C6H6N2O2) reacts with sodium nitrite (NaNO2) and sulfuric acid (H2SO4) to produce m-nitrobenzene diazonium sulfate (C6H5N2SO4) and sodium sulfate (Na2SO4). Step 2: Write the balanced equation C6H6N2O2 + NaNO₂ + H₂SO₄ → C6H5N2SO4 + Na₂SO₄ (h) Reaction of m-toluidine with excess Br₂ in aqueous solution Step 1: Write down the reactants and products m-Toluidine (C7H9N) reacts with excess bromine (Br2) in water to produce 3,4,5-tribromotoluene (C7H6Br3) and hydrobromic acid (HBr). Step 2: Write the balanced equation C7H9N + 3 Br₂ → C7H6Br3 + HBr (i) Reaction of p-toluidine with NaNO₂ and HCl Step 1: Write down the reactants and products p-Toluidine (C7H9N) reacts with sodium nitrite (NaNO₂) and hydrochloric acid (HCl) to produce N-nitroso-p-toluidine (C7H8N2O) and sodium chloride (NaCl). Step 2: Write the balanced equation C7H9N + NaNO₂ + HCl → C7H8N2O + NaCl (j) Reaction of p-anisidine with HNO₃ and H₂SO₄ Step 1: Write down the reactants and products p-Anisidine (C8H11NO) reacts with nitric acid (HNO3) and sulfuric acid (H2SO4) to produce 3-nitro-p-anisidine (C8H9N2O3) and water (H2O). Step 2: Write the balanced equation C8H11NO + HNO₃ + H₂SO₄ → C8H9N2O3 + H₂O (k) Reaction of benzanilide with Br₂ and Fe Step 1: Write down the reactants and products Benzanilide (C13H11NO) reacts with bromine (Br2) and iron (Fe) to produce 2-bromoanilide (C13H10NBrO) and ferric bromide (FeBr3). Step 2: Write the balanced equation C13H11NO + Br₂ + Fe → C13H10NBrO + FeBr3

Step-by-step solution

Write down the reactants and products

n-butyryl chloride (C₄H₇COCl) reacts with methylamine (CH₃NH₂) to produce N-methylbutyramide (C₄H₉CONHCH₃) and hydrochloric acid (HCl).

Write the balanced equation

C₄H₇COCl + CH₃NH₂ → C₄H₉CONHCH₃ + HCl (b) Reaction of acetic anhydride with N-methylaniline

Write down the reactants and products

Acetic anhydride (CH3CO)2O reacts with N-methylaniline (C₆H₅NHCH₃) to produce N-methylacetanilide (C₆H₅NHCOC₃) and acetic acid (CH₃COOH).

Write the balanced equation

(CH3CO)2O + C₆H₅NHCH₃ → C₆H₅NHCOC₃ + CH₃COOH (c) Reaction of tetra-n-propylammonium hydroxide with heat

Decomposition Reaction

When tetra-n-propylammonium hydroxide [(C₃H₇)₄NOH] is heated, it decomposes into n-propylamine (C₃H₇NH₂), water (H₂O), and ammonia (NH₃).

Write the balanced equation

(C₃H₇)₄NOH → 3 C₃H₇NH₂ + H₂O + NH₃ (d) Reaction of tetramethylammonium hydroxide with heat

Decomposition Reaction

When tetramethylammonium hydroxide [(CH₃)₄NOH] is heated, it decomposes into dimethylamine (CH₃NHCH₃), water (H₂O), and ammonia (NH₃).

Write the balanced equation

(CH₃)₄NOH → 2 CH₃NHCH₃ + H₂O + NH₃ (e) Reaction of N,N-dimethylacetamide with boiling dilute HCl

Write down the reactants and products

N,N-dimethylacetamide (C₄H₉NO) reacts with boiling dilute hydrochloric acid (HCl) to produce N,N-dimethylamine (C₂H₆N) and acetyl chloride (CH₃COCl).

Write the balanced equation

C₄H₉NO + HCl → C₂H₆N + CH₃COCl ...

Key concepts

Balancing Chemical Equations

Balancing chemical equations is the process of ensuring that the number of atoms for each element is the same on both the reactant and product sides of the equation. This principle adheres to the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction.

For organic chemistry reactions, like the amide formation from n-butyryl chloride and methylamine, it's critical to count the number of carbon, hydrogen, nitrogen, and chlorine atoms on each side of the equation. The balanced equation \(C_4H_7COCl + CH_3NH_2 \rightarrow C_4H_9CONHCH_3 + HCl\) shows equal numbers of each atom on both sides, signifying a balanced state.

• Reactants: 1 butyryl chloride molecule and 1 methylamine molecule.
• Products: 1 N-methylbutyramide molecule and 1 HCl molecule.
• Atoms Balanced: 4 carbon, 11 hydrogen, 1 nitrogen, 1 chlorine.

Organic Synthesis

Organic synthesis involves creating complex organic molecules from simpler ones. It's a crucial method in organic chemistry for creating desired compounds with various applications, from pharmaceuticals to plastics. An example from the given problems is the synthesis of N-methylacetanilide from acetic anhydride and N-methylaniline.

The balanced reaction, \( (CH_3CO)_2O + C_6H_5NHCH_3 \rightarrow C_6H_5NHCOC_3 + CH_3COOH \), demonstrates the transformation of starting materials into a more complex product plus a side product, acetic acid. During organic synthesis, chemists must consider reaction conditions, yields, and purity to create target molecules efficiently and effectively.

Decomposition Reactions

In organic chemistry, decomposition reactions involve breaking down complex molecules into simpler ones, often with the application of heat or a catalyst. These reactions can be critical when studying reaction mechanisms or synthesizing new compounds.

For instance, when tetra-n-propylammonium hydroxide is heated, it decomposes into n-propylamine, water, and ammonia, as expressed by the equation \( (C_3H_7)_4NOH \rightarrow 3 C_3H_7NH_2 + H_2O + NH_3 \). Understanding these types of reactions is essential for predicting the products of thermal degradation and processing materials in industrial applications.

Amine Reactions

Amines are a versatile class of organic compounds characterized by the presence of a nitrogen atom bonded to alkyl or aryl groups. Reactions involving amines, such as their formation or their reaction with other chemicals, are fundamental in organic synthesis.

In the context of the provided solutions, we observe amine formation in decomposition reactions and their reactions with acid chlorides and anhydrides to form amides. An example includes the synthesis of N-methylbutyramide from n-butyryl chloride and methylamine, highlighting the nucleophilic nature of amines as they attack electrophilic carbon atoms in carbonyl compounds.