Phenol Synthesis and Reactions Lecture Practice

These vocabulary flashcards cover the synthesis, industrial manufacture, chemical tests, and major named organic reactions of phenols as presented in the lecture notes.

Cumene Process

The industrial production of phenol and acetone by the oxidation of cumene (isopropylbenzene) to cumene hydroperoxide with air, followed by acid-catalyzed decomposition into phenol and acetone.

Raschig Process

A two-step commercial process for phenol manufacture where benzene is first converted to chlorobenzene using $HCl$ and air ($C_6H_6 + HCl + \frac{1}{2}O_2 \rightarrow C_6H_5Cl + H_2O$) and then hydrolyzed with steam at high temperature to produce phenol and regenerate $HCl$.

Dow's Process

A commercial method for manufacturing phenol from chlorobenzene by reaction with $NaOH$ at $350^{\circ}C$ and $300\,atm$ pressure; the mechanism involves the formation of a benzyne intermediate.

Neutral Ferric Chloride Test

A characteristic test for compounds containing an enolic group ($-C=C-OH$) or phenol, which reacts with neutral $FeCl_3$ to produce a violet-colored coordination complex ($3[Fe(OPh)_6]^{3-}$).

Libermann Nitroso Test

A test used to identify phenols where the sample is treated with $NaNO_2$ and concentrated $H_2SO_4$ to form a green solution that turns red upon dilution with water and deep blue when treated with $NaOH$.

Picric Acid

The compound $2,4,6$-trinitrophenol, a yellow crystalline solid; it is commercially prepared by sulfonating phenol to phenol-$2,4$-disulphonic acid followed by nitration to prevent oxidative loss of the phenol ring.

Ipso Substitution

A chemical reaction involving the displacement of a ring substituent (other than hydrogen) by an incoming electrophile, specifically noted in phenols when groups like $-SO_3H$ or $-COOH$ are replaced by $-NO_2$ or $-Br$.

Reimer-Tiemann Reaction

The formylation of phenols using chloroform ($CHCl_3$) and aqueous $NaOH$ to produce salicylaldehyde, proceeding via a dichlorocarbene ($:CCl_2$) reactive intermediate.

Kolbe-Schmidtt Reaction

The carboxylation of sodium phenoxide with carbon dioxide ($CO_2$) at $120-140^{\circ}C$ under $4-7\,atm$ pressure to yield salicylic acid.

Fries Rearrangement

The acid-catalyzed conversion of phenolic esters (aryl esters) into a mixture of ortho- and para-hydroxy ketones by heating with anhydrous $AlCl_3$.

Gattermann Synthesis

The formylation of phenols or phenolic ethers using hydrogen cyanide ($HCN$) or zinc cyanide ($Zn(CN)_2$) and hydrogen chloride ($HCl$) in the presence of a Lewis acid like $AlCl_3$.

Houben-Hoesch Reaction

An acylation reaction specifically for polyhydric phenols (like resorcinol) using an alkyl nitrile ($RCN$) and $HCl$ in the presence of $ZnCl_2$ catalyst to form a hydroxy ketone.

Lederer-Manasse Reaction

The condensation of phenol with formaldehyde ($HCHO$) in the presence of an acid or base catalyst to form ortho- and para-hydroxybenzyl alcohols, which are precursors to Bakelite and Novolac resins.

Vilsmeier-Haack Reaction

A formylation reaction used on activated aromatic rings like phenols using $N,N$-dimethylformamide ($DMF$) and phosphorus oxychloride ($POCl_3$) to produce aromatic aldehydes.

Claisen Rearrangement

A thermal [3,3]-sigmatropic rearrangement of aryl allyl ethers into ortho-allyl phenols, occurring when the ether is heated to approximately $200^{\circ}C$ without a catalyst.

Zinin Reduction

A selective reduction technique using aqueous ammonium hydrogen sulphide ($NH_4HS$) or sodium sulphide ($Na_2S$) to reduce one nitro group at a time in polynitro aromatic compounds.

Dakin Reaction

The oxidation of ortho- or para-hydroxy aldehydes or ketones with alkaline hydrogen peroxide ($H_2O_2/NaOH$) to yield dihydric phenols such as catechol or quinol.

Elbe's Persulphate Oxidation

The oxidation of monohydric phenols to dihydric phenols (usually the para-isomer) using potassium persulphate ($K_2S_2O_8$) in alkaline solution.

Fenton's Reagent

A solution of hydrogen peroxide ($H_2O_2$) and an iron catalyst (typically $FeSO_4$) used to oxidize phenol into catechol and quinol via a free radical mechanism.

Salol

Phenyl salicylate, an antiseptic compound prepared by the reaction of salicylic acid with phenol in the presence of phosphorus oxychloride ($POCl_3$).

Aspirin

Acetylsalicylic acid, an analgesic synthesized by the acetylation of the hydroxyl group of salicylic acid using acetic anhydride ($Ac_2O$).

Novolac

A linear polymer formed during the initial stage of phenol-formaldehyde condensation under acidic conditions.

Bakelite

A hard, cross-linked thermosetting resin produced by the extensive condensation of phenol and formaldehyde.