Chemistry: CIX Organic Chemistry -III Lesson: Nitrogen Containing Functional Groups Unit-2: Reactions of Amines Lesson Developer: Dr. S.P Bhutani College/Dept: Formerly Associate Professor Department of Chemistry Rajdhani College, University of Delhi Lesson Editor:Dr.N.K Gautam Advisor (Sciences) Institute of Lifelong Learning, University of Delhi

Institute of Lifelong Learning, University of Delhi

1

Contents: 1. Reactions Of Amines A. Alkylation Of Amines B. Exhaustive Methylation C. The Hofmann Elimination D. Acylation Of Amines-Formation Of Amides E. Formation Of Sulphonamides 2. Reactions Of Amines With Aldehydes And Ketones 3. The Mannich Reaction 4. Oxidation Of Amines 5. Electrophilic Aromatic Substitution A. General Features B. Mechanism C. Nitration Of Primary Aromatic Amines D. Sulphonation Of Aniline-Formation Of Sulphanilic Acid E. Nitrosation Of Tertiary Amines 6. Reactions Of Amines With Nitrous Acid A. Reactions Of Primary Aliphatic Amines With Nitrous Acid B. Mechanism Of Diazotisation C. Reactions Of Primary Aromatic Amines With Nitrous Acid D. Reactions Of Secondary Amines With Nitrous Acid E. Reactions Of Tertiary Amines With Nitrous Acid 7. The Hinsberg Test 8. References

2

1.REACTIONS OF AMINES A.Alkylation of Amines We have already seen alkylation of amines as a side reaction in the preparation of primary amines by the ammonolysis of halides. Amines can react with primary alkyl halides to give amines of the next higher class. The reaction proceeds by SN2mechanism. The alkyl halide undergoes nucleophilic substitution with the amine serving as a nucleophilic reagent.

We see that one of the hydrogens attached to nitrogen is replaced by an alkyl group. The reaction is, therefore, referred to as alkylation of amines. In actual practice, when an amine reacts with primary alkyl halide, we first get the formation of alkylated ammonium halide which gets deprotonated to give the secondary amine. The resulting secondary amine is also nucleophilic and can react with another molecule of the halide to give salt of tertiary amine. The result is formation of a complex mixture even when equimolar amounts of amine and the alkyl halide are used.

The over alkylation may be suppressed by using a large excess of amine being alkylated. B. Exhaustive Methylation When alkylation of amines is carried out by using a large excess of alkyl halide, we get the formation of quaternary ammonium salts, in which four alkyl groups replace the four hydrogens of the ammonium ion. This exhaustive alkylation gives a tetraammonium salt.

Institute of Lifelong Learning, University of Delhi

3

When methylation is carried out using excess of methyl iodide, the process is named as exhaustive methylation. For example,

As quaternary ammonium compounds are ionic, they are generally water soluble and have fairly high melting points. On heating they decompose at the melting point.

Methylation of aniline gives methylaniline, dimethylaniline and finally we get quaternary ammonium salt as given below:

C. The Hofmann Elimination We already know that exhaustive methylation of an amine with methyl iodide gives quaternary ammonium salt.

Elimination of the quaternary ammonium salt can take place when quaternary ammonium hydroxide is heated. The products are an alkene, water and tertiary amine.

The reaction is called the Hofmann elimination. Quaternary ammonium hydroxide can be prepared from quaternary ammonium halide by treating with an aqueous solution of silver oxide. For example,

4

Silver halide precipitates from the solution and can be removed by filtration. The quaternary ammonium hydroxide can then be obtained by evaporation of water. Heating of the quaternary ammonium hydroxide results in E2 elimination and formation of an alkene. The elimination follows the Hofmann rule and yields mainly the least substituted alkene. The substrate i.e., the quaternary ammonium salt must contain the β -hydrogen. For example, when 2-butanamine is exhaustively methylated, converted to the hydroxide and heated, elimination takes place to form a mixture of 1-butene and 2-butene. 1-Butene is the major product that is the Hofmann product.

D.Acylation of Amines-Formation of Amides Primary and secondary amines react with acyl halides and acid anhydrides to form substituted amides

Institute of Lifelong Learning, University of Delhi

5

This reaction is a nucleophilic acyl substitution. Tertiary amines, although basic and hence nucleophilic, fail to yield amides because they cannot lose a proton after attaching themselves to carbon. The amine attacks the carbonyl group of an acid chloride in the same way as it attacks the carbonyl group of an aldehyde or a ketone. The acid chloride is much more reactive than an aldehyde or a ketone because the electronegative chlorine atom draws the electron density away from the carbonyl carbon making it more electrophilic. The chloride ion is a good leaving group.

A base such as pyridine or NaOH is often added to neutralise the H—Cl produced. When we use acetic anhydride as an acyling agent, the leaving group is the acetate ion. However, reaction with acetyl chloride is more facile because Cl – is a better leaving group then acetate ion. Aromatic amines can also be converted into amides with acyl chlorides or anhydrides. Acetyl group is introduced more often with acetic anhydride. For example, aniline is converted into acetanilide with acetic anhydride in the presence of even water. Acetanilide can also be prepared by direct heating of aniline with acetic acid, but this process is slower.

6

We can use a mixture of HCl and sodium acetate that creates a buffered medium. It keeps the amine in solution as the ammonium salt is in equilibrium with a small amount of the free amine. The free amine reacts rapidly with acetic anhydride to form the amide in high yield and in a pure state.

Substituted amides of aromatic carboxylic acids are prepared by the SchottenBaumann method. For example, benzanilide is prepared by shaking aniline with benzoyl chloride in the presence of sodium hydroxide in aqueous medium.

E.Formation of Sulphonamides Like acyl chlorides, sulphonyl chlorides are strongly electrophilic in nature. Primary and secondary amines can attack sulphonyl chloride to give an amide of sulphonic acid, called sulphonamides. The reaction takes place in the presence of aqueous sodium hydroxide (Schotten Baumann method).

Institute of Lifelong Learning, University of Delhi

7

Examples

The sulpha drugs are a class of sulphonamides, which are used as antibacterial agents. An examination of the active sulphonamides showed that they have the basic structure in which R=H or a group which could be easily split off, e.g., any acyl group; R′ could be one of a large number of groups, but in most active compounds it is a heterocylic ring system.

All sulpha drugs that have found most successful application in medicine are derivatives of sulphanilamide.

Sulphanilamide is synthesised from acetanilide by chlorosulphonation followed by treatment with ammonia. The final reaction is hydrolysis of the protecting group to give sulphanilamide

8

2.REACTIONS OF AMINES WITH ALDEHYDES AND KETONES We know ammonia reacts with aldehydes and ketones to form compounds called imines. These compounds contain the functional group C=N, which may be considered to be the nitrogen analog of a carbonyl group

When primary amines react with aldehydes and ketones, substituted imines are produced. These are sometimes referred to as Schiff bases.

Even through N-substituted imines are more stable than simple imines, they readily undergo hydrolysis back to the amine and carbonyl compound. However, if either the carbon or nitrogen is substituted by a phenyl group, the resulting imine is quite stable

The reaction of carbonyl compounds with primary amines is simply nucleophilic addition and then elimination. The reaction is generally catalysed by mild acid.

The first is a nucleophilic addition to the carbonyl group. Rapid proton transfer gives the net addition product called hemiaminal, sometimes known as carbylamine this is so reactive that it cannot be isolated. A second acid-catalysed reaction occurs in which water is eliminated from the hemiaminal. The resulting product is the imine.

Institute of Lifelong Learning, University of Delhi

9

3.THE MANNICH REACTION In the Mannich reaction, formaldehyde (or sometimes another aldehyde) is condensed with ammonia, in the form of its salt, and a compound containing an active hydrogen, a ketone or any other carbonyl compound that can undergo easy enolisation.

Instead of ammonia, the reaction can be carried out with salts of primary or secondary amines. The product is referred to as a Mannich base. The following reaction of acetone, formaldehyde and diethylamine is an example.

Arylamines do not normally give this reaction. The Mannich reaction involves an intermediate ammonium ion, which reacts withthe enol form of the ketone (active hydrogen compound). Step 1

Step 2

10

4.OXIDATION OF AMINES Most amines are oxidised by common oxidants such as H2O2, permanganate and peroxy acids. Primary amines are oxidised easily but complex mixture of products often result. They can be oxidised to nitroso compounds with Caro’s acid (H2SO5) or with H2O2 in acetic acid. Hydroxylamines, which are probably intermediates in most cases, can sometimes be isolated, but under the reaction conditions, they are oxidised to nitroso compounds. Primary aliphatic amines can be oxidised in this manner, but the nitroso compound is stable only if there is no -hydrogen atom. If there is -hydrogen, the compound isomerises to the oxime.

yields with KMnO4. An important reagent which oxidises various types of primary amines to nitro compounds is peroxytrifluoroacetic acid.

The mechanism of oxidation of 1° amine with H2SO5 is given below:

Institute of Lifelong Learning, University of Delhi

11

Secondary amines are oxidised to hydroxylamines. Side products are often formed and the yields may be low.

Peroxytrifluoroacetic acid converts secondary nitrosamines into nitroamines.

Tertiary amines are not affected by potassium permanganate, but are oxidised to amine salt by Caro’s reagent, ozone or by hydrogen peroxide.

Cope Elimination We know that tertiary amines are oxidised to amine oxides when either H 2O2 or a peroxy acid is used as an oxidising agent.

Tertiary amine oxides on heating may undergo elimination much like the Hofmann elimination of a quaternary ammonium salt. The reaction is called the Cope elimination. The amine oxide acts as its own base, so a strong base is not needed. The Cope elimination gives the same orientation as the Hofmann elimination, resulting in the formation of least substituted alkene.

12

The Cope elimination is syn elimination and proceeds through a cyclic transition state as given below:

Cope elimination occurs under milder conditions than Hofmann elimination, where sodium hydroxide is used for carrying out the reaction. Cope elimination is useful when a sensitive or reactive alkene has to be synthesised by the elimination of an amine. Because the Cope elimination involves a cyclic transition state, it occurs with syn stereochemistry.

5.ELECTROPHILIC AROMATIC SUBSTITUTION A. General Features Aromatic amines are highly activated toward substitution in the ring by electrophilic reagents. We know amino group contains a lone pair of electrons. They conjugate with π electrons of the benzene nucleus and increase the electron density on the variousortho-parapositions. Any electrophile will attack at these positions. :NH2

+

NH2

+

+

NH2

NH2

Reaction with such amines occurs under mild conditions. Halogenation is so facile that all the unsubstituted ortho and para positions become substituted. For example, bromination of aniline with Br2 in aqueous solution gives 2,4,6-trimobromoaniline at room temperature.

Institute of Lifelong Learning, University of Delhi

13

Some examples are,

B.Mechanism We have seen above that aniline undergoes fast bromination (without a catalyst) using broming water to give the tribromo product. The non-bonding electrons on nitrogen provide resonance stabilisation to the σ complex when the attack takes place at ortho or para positions in aniline

14

Ortho attack

Para attack

Meta attack

It is clear from the above structures that the intermediate obtained from ortho-para attack has got unusual stability due to the structures in which nitrogen bears a positive charge and is joined to the ring by a double bond. When the attack is at the meta- position the nonbonding electrons on nitrogen do not take part in stabilising the intermediate carbocation. Hence, it is less stable than intermediate carbocation obtained from the orthopara attack. Thus, we find NH2 group in aniline is o-, p-directing and strongly activating. In a similar way, we find that –NH–CH3 group is more activating than –NH2 group because of the + I effect of the methyl group and –N(CH3)2 is more activating than –NH– Institute of Lifelong Learning, University of Delhi

15

CH3 group. Thus, –NH2, –NHR and –NR2 groups act as powerful activators and ortho-para directors. For example dimethylaniline on nitrosation gives exclusively pnitrosodimethylaniline.

The dialkylamino group is such a strongly activating substituent that rather mild reaction conditions are required even when a deactivating group is present. For example,

The acetamido group, –NHCOCH3, is ortho-para directing but milder activating than a free amino group. In this case, electron withdrawl by oxygen atom of the carbonyl group makes the nitrogen of an amide much poorer source of electrons than the nitrogen of an amine. In other words the lone pair of electrons on the —NH group, which conjugate with the  electrons are withdrawn by C=O group. This decreases the conjugation of lone pair of electrons of nitrogen with the electrons of the benzene nudeus making it milder activating,

Nitration and bromination of acetanilide takes place under milder conditions to give para product as major

16

C.Nitration of Primary Aromatic Amines Nitration of primary aromatic amines is not generally carried out because nitric acid is an oxidising agent and amines are sensitive to oxidation. Also in strongly acidic medium the amine is converted into the anilinium salt, which because of its positive charge directs the incoming group to meta position.

Nitro group can be introduced into the benzene ring of aniline by indirect method. We protect the amino group by acetylation, carry out the nitration and finally hydrolyse the amide. We can get p-nitroaniline by the following route.

We have seen in halogenation substitution tends to occur at every available ortho or para position. If we wish to introduce only one group at the para position, we can follow a similar procedure via protection and deprotection of the amino group.

Institute of Lifelong Learning, University of Delhi

17

When para position is occupied attack may take place at the ortho position as given below:

Nitration of tertiary aromatic amines can be accomplished conveniently and in good yields by carrying out the nitration with concentrated nitric acid in glacial acetic acid.

The ortho-para ratio is 1 : 2 and the amount of 2, 4-dinitrodimethylaniline depends on the reaction conditions. D.Sulphonation of Aniline-Formation of Sulphanilic Acid Aniline cannot be sulphonated in the usual way because it reacts with sulphuric acid to form anilinium hydrogensulphate, which on heating at 180–200°C gives the p-isomer as the chief product. This p-isomer (p-aminobenzenesulphonic acid ) is known as sulphanilic acid. It exists as a dipolar ion (sometime called as Zwitterion). As –NH2 group is a stronger base than –SO3– group, the hydrogen ion is attached to nitrogen rather than oxygen.

18

Sulphanilic acid is a salt and exists as dipolar ion. It has high melting point and is insoluble in organic solvents as well as in water. In alkaline solution, the strongly basic hydroxide pulls hydrogen ion away from weakly basic —NH2 group to yield paminobenzenesulphonate, which like most sodium salts, is soluble in water. In acidic medium, the structure of sulphanilic acid does not change and therefore, the compound remains insoluble.

E.Nitrosation of Tertiary Amines We have already seen that dimethylaniline on treatment with nitrous acid (NaNO 2 + dil. HCl) at 0–5°C gives exclusively p-nitrosodimethylaniline. Ring nitrosation takes place by the attack of either nitrosonium ion, NO+ or H2O+—NO. The nitrosonium ion is a weak electrophile, nitrosation ordinarily occurs in rings bearing powerful activating dialkyl amino (–NR2)or hydroxyl group.

Institute of Lifelong Learning, University of Delhi

19

6.REACTIONS OF AMINES WITH NITROUS ACID Nitrous acid (HNO2) is a weak, unstable acid. It is always prepared in situ i.e., by treating NaNO2 with aqueous solution of a strong acid (HCl or H 2SO4). Nitrous acid reacts with all classes of amines. We get different products with primary, secondary and tertiary amines. The products also depend on whether the amine is aliphatic or aromatic. On the basis of the products formed, we can differentiate between them. A. Reactions of Primary Aliphatic Amines with Nitrous Acid Primary aliphatic amines react with nitrous acid to yield highly unstable diazonium salts. The reaction is called diazotisation. Even at low temperatures aliphatic diazonium salts decompose spontaneously by losing N2 to produce mixtures of alkenes, alcohols and alkyl halides

Diazotisations of primary aliphatic amines are of little synthetic value. However, evolution of nitrogen is quantitative and is used in some analytical procedures. B. Mechanism of Diazotisation In acid solution, nitrous acid may protonate and lose water to give the nitrosonium ion, +

N == O. The nitrosonium ion appears to be the reactive intermediate in most reactions of amines with nitrous acid. Nitrosonium ion attacks the primary amine to generate

20

nitrosoamine. Nitrous acid is generated in situ by mixing sodium nitrite with cold dilute hydrochloric acid.

N-Nitrosoamine tautomerises by proton shift from nitrogen to oxygen to form diazohydroxide. Then in the presence of acid diazohydroxide loses water to form the diazonium ion

Alkanediazonium salts are unstable. They decompose to give nitrogen and carbocations.

C. Reactions of Primary Aromatic Amines with Nitrous Acid The diazonium ions produced by the reaction of primary aromatic amines with nitrous acid are more stable than alkanediazonium ion because of resonance. The π electrons of the benzene nucleus can conjugate with π electrons of the N=N bond inducing stability. They do not decompose at an appreciable rate and are quite stable when the temperature of the reaction mixture is kept below 5°C.

For example, aniline on diazotisation gives benzenediazonium chloride when treated with sodium nitrite and dilute hydrochloric acid at 0–5°C

Institute of Lifelong Learning, University of Delhi

21

Diazotisation

reactions

of

primary

aromatic

amines

are

of

considerable

+

syntheticimportance because the diazonium group, - N º N, can be replaced by a variety of other function groups. These reactions have been discussed separately. D. Reactions of Secondary Amines with Nitrous Acid Secondary amines, both aliphatic and aromatic, react with nitrous acid to yield NNitrosoamines. N- Nitrosoamines usually separate from the reaction mixture as oily yellow liquids. Some examples are given below:

Secondary amines react with nitrosonium ion to form secondary N- nitrosoamines. They are quite stable under the reaction conditions because they do not have the –N–H proton needed for the tautomerism to form a diazoniun ion.

Some N-nitrosoamines have been shown to cause cancer in the laboratory animals. E. Reactions of Tertiary Amines with Nitrous Acid When a tertiary aliphatic amine is treated with nitrous acid, an equilibrium is established between the tertiary amine, its salt and an N- nitrosoammonium compound

N-Nitrosoammonium compounds are stable at low temperatures, however, at higher temperatures and in aqueous acid they decompose to produce aldehydes and ketones. These reactions are of little synthetic importance.

22

As shown earlier tertiary aromatic amines undergo ring substitution when treated with nitrous acid at low temperatures. Nitrosation takes place exclusively at the para-position. If para-position is occupied, then nitrosation takes place at the orthoposition.

7.THE HINSBERG TEST The Hinsberg Testis performed to show whether an amine is primary, secondary or tertiary. The test can be performed with a mixture of amines or with individual amine. Sulphonamide formation is the basis of this test. A Hinsberg Test involves two steps. First, a mixture containing a small amount of the amine and benzenesulphonyl chloride is shaken with excess of aqueous potassium hydroxide. Next, after allowing time for the reaction to take place, the mixture is acidified. Each type of amine gives a different visible results after each of the these two stages of the test.

1.

Primary amines react with benzenesulphonyl chloride to form N-substituted benzenesulphonamide. This has an acidic hydrogen attached to nitrogen. With excess of potassium hydroxide, a water-soluble potassium salt is obtained i.e., after first stage we get a clear solution. Acidification of this solution will cause precipitation of the sulphonamide and we get a precipitate after second stage.

2.

Secondary amines react with benzenesulphonyl chloride in aqueous potassium hydroxide to form insoluble N,N′-disubstituted sulphonamide. This has no acidic hydrogen, it does not dissolve in potassium hydroxide solution. Acidification of the mixture obtained from secondary amine produces no visible result, it remains as a precipitate.

3.

If the amine is tertiary and if it is water insoluble, no change will take place in the mixture as we shake it with benzenesulphonyl chloride and aqueous potassium hydroxide. When we acidify the mixture, the tertiary amine will dissolve because it will form a water soluble salt. The reactions with 1°, 2° and 3° amines are summarised below:

Institute of Lifelong Learning, University of Delhi

23

REFERENCES: 1.Organic Chemistry by Morrison, R.T. and Boyd, R.N. Darling Kindersley (India) Pvt. Ltd. (Pearson Education). 2. Organic Chemistry by Graham Solomons, T.W. John Wiley and Sons. 3. Introduction to organic chemistry by Andrew Streitwieser, Jr. and Claylon H. Heathcock Macmillan Publishing Company. 4. Organic Chemistry by Seyhan Ege A.I.T.B.S. Publishers and Distributers J5/6, Krishan Nagar, Delhi- 110051. 5. Advanced Organic Chemistry by Jerry March John Wiley and Sons. 6. Organic Chemistry by L.G. Wade, Jr. Pearson Education. 7. A Guide Book to Mechanism in Organic Chemistry by Peter Sykes – Pearson Education.

24

Reactions of Amines.pdf

Lesson: Nitrogen Containing. Functional Groups. Unit-2: Reactions of Amines. Lesson Developer: Dr. S.P Bhutani. College/Dept: Formerly Associate Professor. Department of Chemistry. Rajdhani College, University of Delhi. Lesson Editor:Dr.N.K Gautam. Advisor (Sciences). Institute of Lifelong Learning, University of Delhi.

1MB Sizes 0 Downloads 200 Views

Recommend Documents

Spirocyclization reactions and antiproliferative activity of ... - Arkivoc
DOI: http://dx.doi.org/10.3998/ark.5550190.p009.958. Abstract ...... colorimetric microculture assay with the MTT endpoint.38 Briefly, 5 × 103 cells were plated.

Adsorption Reactions of Dimethylaluminum ...
CHART 1: Stationary Points along the Initial Water Adsorption on the H/Si(100)-2 × 1 Surface as ... atomic and molecular electronic structure system (GAMESS).

Spirocyclization reactions and antiproliferative activity of ... - Arkivoc
2 and (2R,3R)-(-)-4a were determined by electronic circular dichroism (ECD), ..... (±)-26b and (±)-27a-(±)-27b isomerize at C-2 atom like the diastereoisomers of ...

Study of reactions of pentafluorophenylhydrazine with ... - Arkivoc
Dec 26, 2016 - Chemical and Food Technology, Slovak University of Technology, .... 2.5. 323.04472. 323.04496. -0.74. 6f. Methanol. (Toluene). 168-171. 65 ..... supported by grants from the Ministry of Education of the Slovak Republic No.

Nuclear Reactions POGIL.pdf
Download. Connect more apps... Try one of the apps below to open or edit this item. Nuclear Reactions POGIL.pdf. Nuclear Reactions POGIL.pdf. Open. Extract.

Students' Reactions to Undergraduate Science
The Higher Education Learning Project is a working alliance of teachers in higher ... Dietrich Brandt; to the Institute for Educational Technology, University of ...

MULTIPHASE REACTIONS Doctor of Philosophy ...
Doctor of Philosophy in Engineering, is a bonafide record of the investigation ...... bladed glass disk turbine impeller with the provision of speed regulation,.

9.3 Predicting Redox Reactions
Write the half-reaction equations (reverse the direction of the oxidation reaction). 6. Use multipliers to balance the electrons. 7. Combine the half reactions to give ...

Product Identification and Kinetics of Reactions of ... - ACS Publications
Department of Chemistry, Hope College, Holland, Michigan 49423. ReceiVed: July 29, 1999; In Final Form: January 11, 2000. The gas-phase products of the reaction between HNO3/H2SO4/H2O acid solutions and HCl were identified using IR and UV-Vis spectro

Dynamics of electron transfer reactions in the presence ...
Received 8 July 2009; accepted 8 August 2009; published online 4 September 2009. A generalized ... Things are different for the inner sphere degrees of free- dom. They are not in ...... Scientific Computing Center NERSC, which is supported.

Reactions of fused pyrrole-2,3-diones with dinucleophiles - Arkivoc
atom. Additionally, the β-CH and NH groups are oriented on different sides with respect to ... used pyrrolobenzoxazinetriones 1, which have an electron-acceptor ...

Multiple reactions solidification of undercooled melt ...
Sample analysis. Temperature measurements. Simulation. Modeling. Phase transformations. Cooling curve. Prospective. Federal Institute for. Materials Research and Testing. Acknowledgements. References. I. II. III. IV. V. VI. D. Tourret 1*, T. Volkmann

Enrymatic Reactions of Ctostridium dfficile-ln Aelgbic ...
Copper(l) salts- may. also react with iiror'to form oH . ... TABLE 1' comparison of C' dfficile enzyme detection in reactions with pAL in different incubation ...

neutron reactions - Keith E. Holbert
The reaction rate in units of reactions/second can be computed by multiplying RR by the material volume. In similar fashion, the total number of reactions can be ...

Students' Reactions to Undergraduate Science
and things which are bigger than us, and things we can't see. These are ..... Such a view of the data ought to inform a critical reading of the book. The extracts ...

Reversible-Reactions-derivation.pdf
There was a problem previewing this document. Retrying... Download. Connect more apps... Try one of the apps below to open or edit this item.

Chapter 05 Chemical Reactions - MOBILPASAR.COM
iron atoms. Bloom's Level: 5. Evaluate. Difficulty: Medium. Gradable: automatic. Subtopic: The Mole (Definition and Avogadro's Number). Topic: Chemical Calculations. 8. How many moles of chloroethylene (C2H3Cl) contain 5.47 × 1026 molecules? A. 3.29

Name reactions B.Sc.III.pdf
There was a problem previewing this document. Retrying... Download. Connect more apps... Try one of the apps below to open or edit this item. Name reactions ...

NAME REACTIONS .pdf
NAME REACTIONS IN ORGANIC CHEMISTRY. SL. NO. NAME REACTION EQUATION OF REACTION. 1 Aldol condensation. The aldol and ketol readily lose ...

Students' Reactions to Undergraduate Science
Such a view of the data ought to inform a critical reading of the book. ...... while good events tend to become surrounded in a rather general halo of good feelings.