20.3 Nucleophilic Substitution in Acyl Chlorides CHsCCI CH3COH - C6HsCOCCH Benzoyl chloride Acetic acid Acetic benzoic anhydride The product is a mixed anhydride. Acetic acid acts as a nucleophile and substi Ites for chloride on the benzoyl group TABLE 20.2 Conversion of Acyl Chlorides to Other Carboxylic Acid Derivatives Reaction(section) and comments General equation and specific example Reaction with carboxylic acids(Section 20.4)Acyl chlorides react with carboxylic acids to yield acid anhydrides. When this RCCI+ RCOH reaction is used for preparative purposes, Carbo a weak organic base such as pyridine is chloride normally added Pyridine is a catalyst for the reaction and also acts as a base to neutralize the hydrogen chloride that is CHa(CH))SCCl CH3 ( CH2)s COH pyridine, CH3(CH2)5 COC(CH2)SCH3 Heptanoyl Heptad chloride acid (78-83% aLcohols(Section 15.8)Acyl o with alcohols to form ction is typically carried out RCC|+R'OH—>RcoR!+HC of pyridine. Alcohol Ester chloride chloride CHsCCI +(CH3)3COH CHs COC(CH3)3 Benzoyl ert-B tert-B chloride Reaction omonia and amines sec tion 20.1 3)acyl chlorides react with mmonia and amines to form amides. A RCCI RNH HO →>RCNR2+H2O+C| base such as sodium hydroxide is normally Acyl Ammonia Hydroxide ter Chloride added to react with the hydrogen chlor- de produced C6HsCCI HN C6H5C—N Ben (87-91%) Hydrolysis(Section 20. 3) Acyl chlorides react with water to yield carboxylic acids. In base, the acid is converted to its carbox- RCCI H2O RCOH+ HCI ylate salt. The reaction has little prepara Wate Carboxylic Hydrogen tive value because the acyl chloride is nearly always prepared from the carboxyl- ic acid rather than vice versa CHsCH2CCI H20-C5HsCH2COH HCI Phenylacetyl Water Phenylac Back Forward Main MenuToc Study Guide ToC Student o MHHE WebsiteThe product is a mixed anhydride. Acetic acid acts as a nucleophile and substi￾tutes for chloride on the benzoyl group. C6H5CCl O Benzoyl chloride C6H5COCCH3 O O Acetic benzoic anhydride CH3COH O Acetic acid 20.3 Nucleophilic Substitution in Acyl Chlorides 781 TABLE 20.2 Conversion of Acyl Chlorides to Other Carboxylic Acid Derivatives Reaction (section) and comments Reaction with carboxylic acids (Section 20.4) Acyl chlorides react with carboxylic acids to yield acid anhydrides. When this reaction is used for preparative purposes, a weak organic base such as pyridine is normally added. Pyridine is a catalyst for the reaction and also acts as a base to neutralize the hydrogen chloride that is formed. Reaction with alcohols (Section 15.8) Acyl chlorides react with alcohols to form esters. The reaction is typically carried out in the presence of pyridine. Reaction with ammonia and amines (Sec￾tion 20.13) Acyl chlorides react with ammonia and amines to form amides. A base such as sodium hydroxide is normally added to react with the hydrogen chlor￾ide produced. Hydrolysis (Section 20.3) Acyl chlorides react with water to yield carboxylic acids. In base, the acid is converted to its carbox￾ylate salt. The reaction has little prepara￾tive value because the acyl chloride is nearly always prepared from the carboxyl￾ic acid rather than vice versa. General equation and specific example Acyl chloride RCCl O X Carboxylic acid RCOH O X Acid anhydride RCOCR O X O X HCl Hydrogen chloride pyridine Heptanoyl chloride CH3(CH2)5CCl O X Heptanoic acid CH3(CH2)5COH O X Heptanoic anhydride (78–83%) CH3(CH2)5COC(CH2)5CH3 O X O X pyridine Benzoyl chloride C6H5CCl O X tert-Butyl alcohol (CH3)3COH tert-Butyl benzoate (80%) C6H5COC(CH3)3 O X Ester RCOR O X HCl Hydrogen chloride ROH Alcohol Acyl chloride RCCl O X Amide RCNR 2 O X Cl Chloride ion H2O Water R 2NH Ammonia or amine HO Hydroxide Acyl chloride RCCl O X Carboxylic acid RCOH O X HCl Hydrogen chloride H2O Water Acyl chloride RCCl O X NaOH H2O Benzoyl chloride C6H5CCl O X Piperidine HN N-Benzoylpiperidine (87–91%) C6H5C±N O X Phenylacetyl chloride C6H5CH2CCl O X Water H2O Phenylacetic acid C6H5CH2COH O X Hydrogen chloride HCl Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website