Carboxylic Acids: Visual Reaction Pathways

Reaction Pathways from/to RCOOH

Synthesis Routes (→ RCOOH):

1° Alcohol oxidation: CCCO (1-propanol) --[KMnO4/H+]--> CCC(=O)O (propanoic acid)
Grignard: CCBr (ethyl bromide) + Mg → CCMgBr + CO2 → CCC(=O)O (propanoic acid) --[H3O+]-->
Nitrile: CC#N (acetonitrile) + H3O+/reflux → CC(=O)O (acetic acid)

Reactions from RCOOH:

Transformation	SMILES: Reactant → Product	Reagent
HVZ (acetic → bromoacetic)	`CC(=O)O` → `OC(=O)CBr`	Br2/Red P
Fischer esterification (acetic + ethanol)	`CC(=O)O` + `CCO` → `CCOC(=O)C`	H2SO4/heat
SOCl2 (acetic → acetyl chloride)	`CC(=O)O` → `CC(=O)Cl`	SOCl2
LiAlH4 (acetic → ethanol)	`CC(=O)O` → `CCO`	LiAlH4/ether
Decarboxylation (sodium acetate → methane)	`CC(=O)[O-]` → `C` (methane)	NaOH+CaO/heat
Kolbe (acetate → ethane)	2×`CC(=O)[O-]` → `CC` (ethane)	Electrolysis (anode)
Grignard (benzoic → benzyl alcohol)	`OC(=O)c1ccccc1` → `OCc1ccccc1`	LiAlH4

Acidity Visualization

$\text{pKa}: \underbrace{\text{Cl}_3\text{CCOOH}}_{0.65} < \underbrace{\text{ClCH}_2\text{COOH}}_{2.87} < \underbrace{\text{HCOOH}}_{3.75} < \underbrace{\text{CH}_3\text{COOH}}_{4.76} < \underbrace{(\text{CH}_3)_3\text{CCOOH}}_{5.05}$

Lower pKa = stronger acid (left is strongest)

Apparatus for Key Reactions

Reflux setup for nitrile hydrolysis and saponification: Reflux apparatus for organic synthesis Carboxylic acid synthesis via nitrile hydrolysis or saponification uses standard reflux with a condenser.