厦门大学化学化工学院：《有机化学》课程教学资源（课件讲稿，双语版）第十三章 含氮芳香化合物 Aromatic Nitrogen Compounds（2/3）

13,2芳香胺 Arylamines (Aromatic Amines

Organic Chemistry Organic Chemistry Xiamen Xiamen University University 13.2 芳香胺 Arylamines (Aromatic Amines)

13.2.1 Nomenclature NH NHo Benzenamine 1-Naphthalenamine 1.3-benzenediamine NHC6H5 nh N-Phenylbenzenamine N-Phenyl-2-naphthalenamine

Organic Chemistry Organic Chemistry Xiamen Xiamen University University 13.2.1 Nomenclature NH2 NH2 NH2 NH2 Be nz e nami n e 1- N aphth a l e nami n e 1,3-be nz e n ediam i n e NH N - P henyl b enzenami n e N - P henyl-2-n ap hth ale nami n e NH C 6 H 5

a Three common arylamines have the following 三 names: NH NHCH NH, NH2 CH3 OCH ①D Aniline N-Methylaniline p-Toluidine p-Anisidine ⑨D

Organic Chemistry Organic Chemistry Xiamen Xiamen University University Three common arylamines have the following names: NH 2 NHCH 3 NH 2 NH 2 CH 3 OCH 3 A niline N - M ethylaniline p - T oluidine p - A nisidine

13.2.2 Physical Properties of Arylamines Name mp p pKa a. Aniline 61844.58 P-Toluidine 44200508 P-Anisidine 57244530 E//P-Chloroaniline 732324.00 P-Nitroaniline 1483321.00 a Diphenylamine 533020.80

Organic Chemistry Organic Chemistry Xiamen Xiamen University University 13.2.2 Physical Properties of Arylamines Diphenylamine 53 302 0.80 P-Nitroaniline 148 332 1.00 P-Chloroaniline 73 232 4.00 P-Anisidine 57 244 5.30 P-Toluidine 44 200 5.08 Aniline -6 184 4.58 Name mp bp pKa

13.2.3 Preparation (CH3)2C- NO EtOH (CH3) C NH Fe. hCl CH NO CH NH ON RNHA ①D Br O2N-〈 NHR NO ⑨D NO2

Organic Chemistry Organic Chemistry Xiamen Xiamen University University 13.2.3 Preparation (CH3 ) 3 C NO 2 H 2 , P t EtOH (CH3 ) 3 C N H 2 CH 3 NO 2 O 2 N Fe, H C l CH 3 N H 2 H 2 N O Br 2 N NO 2 RNH 2 O 2 N NHR NO 2

CH NO CH3 NO Hs, NH3 NO2 NH COH 2 NH Naoh NH

Organic Chemistry Organic Chemistry Xiamen Xiamen University University NH O O X 2 NaOH NH 2 CO 2 H CH 3 NO 2 NO 2 H 2S, NH 3 CH 3 N H 2 NO 2

13.2. 4 Basicity of Arylamines d Arylamines are less basic than e. alkylamines because the nitrogen lonepair electrons are delocalized by orbital overlap with the aromatic ring pi electron system and are less available for bonding As a general rule substituents that increase the reactivity of an aromatic ring toward electrophilic substitution also increase the basicity of the corresponding arylamine

Organic Chemistry Organic Chemistry Xiamen Xiamen University University 13.2.4 Basicity of Arylamines „ Arylamines are less basic than alkylamines because the nitrogen lonepair electrons are delocalized by orbital overlap with the aromatic ring pi electron system and are less available for bonding. „ As a general rule, substituents that increase the reactivity of an aromatic ring toward electrophilic substitution also increase the basicity of the corresponding arylamine

Y一 - NH2 H2o=Y -NH3 +Oh Stronger Substituents, Y pKa base -NH 2 6.15 OH534 Activating CH roups 508 4.63 Cl 3.98 ①D Br 3.86 Deactivating C≡N1.74gru ps 可 Weaker NO 1.00 base

Organic Chemistry Organic Chemistry Xiamen Xiamen University University NH 2 OH CH 3 H Cl Br C N NO 2 6.15 5.34 5.08 4.63 3.98 3.86 1.74 1.00 A ctiv atin g groups De a ctiv atin g gr o up s S ub stitu e nts, Y pK a Y NH 2 + H 2 O Y NH 3 + O H Stronger base Weaker base

13.2.5 Reactions of Arylamines

Organic Chemistry Organic Chemistry Xiamen Xiamen University University 13.2.5 Reactions of Arylamines

Electrophilic Aromatic Substitution Q- Amino substituents are strongly activating g groups in electrophilic aromatic substitution reactions NH2 B1 Br. Br HoO Br Aniline 2. 4. 6-Tribromoaniline (1009%)

Organic Chemistry Organic Chemistry Xiamen Xiamen University University Electrophilic Aromatic Substitution „ Amino substituents are strongly activating groups in electrophilic aromatic substitution reactions. NH 2 NH 2 Br Br Br An i lin e 2,4,6-Tribr o m oani l i n e Br 2 H 2 O (10 0 % )