Chap 18 Carboxylic acids and their derivatives. nucleophilic substitution at the acyl carbon 18.1 Introduction The carboxyl group,-COOH,-CO2H, is one of the most widely occurring functional groups in chemistry and biochemistry. Not only are carboxylic acids themselves important, but the carboxyl group is the parent group of a large family of related compounds
Chap 18. Carboxylic acids and their derivatives. Nucleophilic substitution at the acyl carbon 18.1 Introduction The carboxyl group, -COOH, -CO2H, is one of the most widely occurring functional groups in chemistry and biochemistry. Not only are carboxylic acids themselves important, but the carboxyl group is the parent group of a large family of related compounds
All of these carboxylic acid derivatives contain the acyl group, RCO- As a result, they are often called acyl compounds. They are called carboxylic acid derivatives R Cl Acyl (or acid) chloride r NH2 Amide (酰氯) (酰胺) R R Acid anhydride R (酸酐) NR(x-取代酰胺) R o—R Ester (酯) R NRR"(N,N-二取代酰胺)
All of these carboxylic acid derivatives contain the acyl group, RCO-. As a result, they are often called acyl compounds. They are called carboxylic acid derivatives. R O Cl R O O O R R O O R Acyl (or acid) chloride Acid anhydride Ester R O NH2 R O NHR' R O NR'R'' Amide （ 酰 胺 ） （ 酰 氯 ） （ 酸 酐 ） （ 酯 ） （ N-取 代 酰 胺 ） （ N,N-二 取 代 酰 胺 ）
18.2 Nomenclature and physical properties 18.2A Carboxylic acids HCOOH CH3 COOH Methanoic acid Ethanoic acid Formic acid) (Acetic acid) (甲酸)(蚁酸) (乙酸) 654321 ChrCHChchchbcooh CH3CH=CHCH, CH2COOH CH 3 4-Hexenoic acid 4-Methylhexanoic acid (4-己烯酸) (4-甲基己酸)
18.2 Nomenclature and physical properties 18.2A Carboxylic acids CH3 CH2 CHCH2 CH2 COOH CH3 4-Methylhexanoic acid 4 3 2 1 CH3 CH=CHCH2 CH2 COOH 6 5 4 3 2 1 4-Hexenoic acid HCOOH CH3 COOH Methanoic acid Ethanoic acid (Formic acid) (Acetic acid) （ 甲 酸 ） （ 蚁 酸 ） （ 乙 酸 ） （ 4-甲 基 己 酸 ） （ 4-己 烯 酸 ）
CICHCOOH CI3CCOOH CH3 (CH2)3CO2H Chloroethanoic acid Trichloroethanoic acid Pentanoic acid (氯代乙酸) (三氯代乙酸) (戊酸) COOH COOH COOH Benzoic acid 1-Naphthoic acid 2-Naphthoic acid (1-萘酸) (2-萘酸)
ClCH2 COOH Chloroethanoic acid （ 氯 代 乙 酸 ） Cl 3 CCOOH Trichloroethanoic acid （ 三 氯 代 乙 酸 ） CH3 (CH2 ) 3 CO2 H Pentanoic acid （ 戊 酸 ） （ 1-萘 酸 ） COOH COOH COOH Benzoic acid 1-Naphthoic acid 2-Naphthoic acid （ 2-萘 酸 ）
18.2C Acidity of carboxylic acids Most unsubtituted carboxylic acids have Ka values in the range of 10-4-10-(pka=4-5) COoH CooNa t Naoh t ho Benzoic acid(pKa=4.15) Sodium benzoate (苯甲酸钠) (water insoluble) (water soluble co2H+ NaHCO3— -CO2Na CO2 H20
18.2C Acidity of carboxylic acids Most unsubtituted carboxylic acids have Ka values in the range of 10-4—10-5 (pka = 4-5). COOH + NaOH COONa + H2O Benzoic acid Sodium benzoate (water insoluble) (water soluble) （ 苯 甲 酸 钠 ） CO2H + NaHCO3 CO2Na + CO2 + H2O (pKa = 4.15)