《有機(jī)化學(xué)》英文教學(xué)課件：Chap_12_2012-1_

1、1,Claisen condensations involve a ester with -hydrogen and the carbonyl group of another ester. The Claisen condensation bears the same relationship to the aldol condensation that the addition of a nucleophile to an ester does to the addition to an aldehyde or ketone. If a ester contains -hydrogen,

2、we can use the Claisen condensation to produce -keto ester.,3. Claisen condensation ( Ester condensation ),2,Mechanism of Claisen condensation :,3,A Claisen condensation between two different esters both with -hydrogen is call a crossed Claisen condensation. Thus two products are possible. There are

3、 some simple ways to limit the possibilities in a crossed Claisen reaction. If one partner has no -hydrogen, it can function only as an acceptor, and not as the nucleophile partner in the reaction.,4,Leaving group,5,Acetylacetic ester has some special chemical properties:,react with sodium to releas

4、e hydrogen gas,react with ferric chloride cause color reaction,6,These special chemical properties are due to the tautomerism of acetylacetic ester.,keto-form( 93 % ),enol-form( 7 % ),4. Keto-enol Tautomerism,P. 128,7,1) Simple ketones are almost keto-form.,Summary of Keto-enol tautomerism:,8,3) If

5、the enol form cause the conjugate system become longer or form intramolecular hydrogen bond, the enol form is stable.,9,P. 128 P. 133 9-14 (2),10,Acidic cleavage :,5.Cleavage reaction of acetylacetic ester,11,Ketonic cleavage :,12,Chapter 12 Nitrogenous Compounds and Alkaloids,Section 1 Amine,. Clas

6、sification and Nomenclature,ammonia,13,quaternary ammonium salt,quaternary ammonium hydrate,tertiary amine,Quaternary ammonium hydrates are strong base. The basicity of quaternary ammonium hydrates are similar to sodium hydroxide.,季銨鹽,季銨堿,14,胺：有機(jī)非離子型 (amine ),銨：離子型 (ammonium ion ),氨：氨水、氨氣或有機(jī)基團(tuán) ( amm

7、onia，amino ),15,16,The systematic nomenclature names amines analogously to alcohol. Another method names amines as substituted alkanes. . The names of aromatic amines are base on the parent compound, called benzenamine（苯胺） by the official world and aniline (or aminobenzene) by everyone else Amines b

8、earing different R are named by ordering the groups alphabetically,17,methylamine,diethylamine,triethylamine,Benzylethylmethylamine 甲乙芐胺,N,N-dimethylaniline,18,1-amino-3-methylbutane,benzyldodecyldimethyl ammonium bromide or bromo-geramine, 溴化二甲基十二烷基芐基銨,新潔爾滅，苯扎溴銨，disinfector（消毒劑）,19,II. Structure of

9、 Amines,20,ammonia,methylamine,aniline,trimethylamine,21,. Preparation of Aromatic Amine,Fe/HCl can reduce nitro group but can not reduce carbon-carbon double bond.,Ni, Pd, Pt,22,. Chemical Properties:,1. Basicity and Salt Forming,A strongly basic amine is a good competitor for H+ and its ammonium i

10、on is a relatively weak acid (more stable); a weakly basic amine is less effective competitor for H+, and its ammonium ion is a relatively strong acid.,ammonium ion,23,Sequence of the basicity of amines,24,Procaine （普魯卡因）,procaine hydrochloride, local anesthesia,25,鹽酸雙氯醇胺、鹽酸克侖特羅,Clenbuterol hydrochl

11、oride, Spiropent,瘦肉精,26,2. Acylation,amide,27,28,Acetanilide had been used as antifebric, but its toxicity is too high.,Phenacetin非那西丁,Acetanilide,Paracetamol撲熱息痛,29,3. Sulfonylation,benzene sulfonyl chloride,p-toluenesulfonyl chloride,30,crystal,-I effect,weak acid,31,The above reaction is named Hi

12、nsberg Reaction（興斯堡反應(yīng) ）. Using this reaction can distinguish primary, secondary and tertiary amines. The products of primary amines react with benzene sulfonyl chloride is weak acid, so can dissolve in sodium hydroxide solution. The products of secondary amines are crystal, and can not dissolve in s

13、odium hydroxide solution. For tertiary amines, this reaction can not take place.,32,4. React with nitrous acid (HNO2),(1) Primary amines,33,(2) Secondary amines,亞硝胺,34,(3) Tertiary amines,Aliphatic tertiary amines do not react with nitrous acid to give an isolable product.,35,emerald green solid,Act

14、ually, we use sodium nitrite/hydrochloric acid NaNO2/HCl instead of nitrous acid (HNO2).,yellow solid,36,Because primary amines react with nitrous acid will give nitrogen gas; secondary amines will produce yellow oil and the products of aromatic tertiary amines are yellow solid. So it is easy to dis

15、tinguish primary, secondary and tertiary amine by reacting with nitrous acid.,37,Something More:,Nitrosoamines are important because many are known to be potent carcinogens. This finding has led to a controversy over the use of sodium nitrite (NaNO2) as a preservative in foods because it might be a

16、nitrosating agent under physiological conditions, or under the conditions in which food is prepared. The classic example is the frying of bacon, which generates nitrosoamines. However, the evidence is not definitive on this point. Many foods (spinach), even our own bodies, produce nitrites.,38,N-Nit

17、rosodimethylamine,39,white precipitation,5. Special Reaction of Aniline,40,V. Important Amines,Choline（膽堿）,Acetylcholine （乙酰膽堿）,41,Dopamine (DA，多巴胺), the decrease of DA will cause parkinsonism.,42,瑞典阿爾維德卡爾松(Arvid Carlsson ),美國(guó)保羅格林加德 (Paul Greengard ),奧地利埃里克坎德?tīng)?(Eric Kandel ),The Nobel Prize in Physi

18、ology or Medicine 2000,43,5-Hydroxytryptamine (5-羥色胺) , Serotonine (血清胺 ),44,Melatonin (MLT),褪黑素 (又稱松果體素或腦白金),45,Fluoxetine (氟西汀 ),Prozac (百憂解),Are you prozac today?,46,Paroxetine，Seroxat（帕羅西汀，賽樂(lè)特）,47,(S)和(R)-西布曲明,48,epinephrine,norepinephrine,isoprenaline, synthetic medicine,49,ephedrine,deoxyephedrine,