Amines & Diazonium Salts — Full Cornell Notes — Notes | NoteTube

Question	Answer
What are the three classes of amines?	Primary ( $RNH_{2}$ ), Secondary ( $R_{2}NH$ ), Tertiary ( $R_{3}N$ ) — classified by number of alkyl/aryl groups on nitrogen
What is the aqueous basicity order of aliphatic amines?	2° > 1° > 3° > $NH_{3}$ — solvation of conjugate acid controls the order
Why does 3° amine fall behind in aqueous basicity?	$R_{3}NH^{+}$ has three bulky alkyl groups; steric hindrance prevents effective hydrogen bonding with water, so conjugate acid is poorly solvated
Why is aniline a weak base?	Lone pair on N is delocalized into benzene ring by resonance → less available for protonation
What amines can Gabriel phthalimide synthesis make?	ONLY primary aliphatic amines (1° aliphatic); cannot make $ArNH_{2}$ , 2°, or 3° amines
What is the carbon count change in Hoffmann bromamide degradation?	Product amine has ONE FEWER carbon than the starting amide ( $RCONH_{2}$ → $RNH_{2}$ )
What does the carbylamine test detect?	ONLY 1° amines — gives foul-smelling isocyanide (R-NC) with $CHCl_{3}$ + 3KOH
How does Hinsberg test differentiate 1° and 2° amines?	1° sulfonamide has N-H → soluble in NaOH; 2° sulfonamide has no N-H → insoluble in NaOH; 3° does not react
What are diazotization conditions?	$ArNH_{2}$ + $NaNO_{2}$ + 2HCl at 0–5 °C → $ArN_{2}^{+}$$Cl^{-}$ ; temperature must stay ≤5 °C
What is the Schiemann reaction and why is it unique?	$ArN_{2}^{+}$ + $HBF_{4}$ → $ArN_{2}^{+}$$BF_{4}^{-}$ →(heat) ArF + $BF_{3}$ + $N_{2}$ ; ONLY reliable route to aryl fluorides

Summary: Amines are nitrogen derivatives classified by substitution degree. In water, solvation effects reverse the expected 3° > 2° > 1° gas-phase basicity to 2° > 1° > 3°. Gabriel synthesis gives only 1° aliphatic amines; Hoffmann degradation gives amines with one fewer carbon. Diazonium salts from aromatic 1° amines are key intermediates for Sandmeyer, Gattermann, Schiemann, and azo-coupling reactions.