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Chapter-2

24

2525

INTRODUCTION:

The present chapter comprises two sections. Section-I comprises

characterization techniques used to characterize the produced compounds (shown in

following chapters). and Section-II comprises the synthesis and characterization of

various Schiff bases of NTOH.

2626

SECTION-I

TECHNIQUES USED FOR CHARACTERIZATION OF COMPOUNDS

2727

2.1 Elemental Analysis

The majority of organic compounds are composed of a relatively small

number of elements. The most important ones are: carbon, hydrogen, oxygen,

nitrogen, sulphur, chlorine, etc. Elementary quantitative organic analysis is used to

determine the content of carbon, hydrogen, nitrogen, and other elements in the

molecule of an organic compound.

2.2 Introduction to Spectrometry

In modern era structure determination is very easy by using various

spectroscopy techniques: the study of the interaction of matter and light (or other

electromagnetic radiations). These techniques have been greatly significant to many

areas of science. For example, by help of spectroscopy we exactly know about orbital

and bonding. But spectroscopy is also important to the scientist because it can be used

to determine unknown molecular structures. Although this arrangement of

spectroscopy will spotlight largely on its applications, some fundamentals of

spectroscopy theory must be considered first.

2.3 Infrared Spectroscopy

Infrared spectroscopic technique [1-4] is of an immense importance to organic

chemists for the identification of the presence of functional groups in the organic

compounds although it does not give the fully data with respect to the molecular

constituents of the organic compounds. However it is used for the identification of the

compounds.

Infrared spectroscopic technique gives the information about the molecular

vibrations or large exactly on the transition between vibrational and rotational energy

levels in the molecule and due to this characteristic; it is of immense help to organic

chemists.

When infrared light is approved through a taster, some of the frequencies are

engrossed while other frequencies are transmitted through the sample. The absorption

2828

of infrared radiation depends on increasing the energy of vibration or rotation

associated with co-valent bond in a molecule.

Radiation absorption in the IR region outcome in the bond excitation

deformations, bending or either stretching. Different bending and stretching vibrations

found at fixed quantized frequencies. When IR light of required frequency is pass or

incident on the compound, amplitude of that vibration because of energy is absorbed.

“An IR spectrum are found If the frequency of vibrations of compounds suitable to

the IR frequency radiations absorbed.”

The sample under investigation is largely in the solid state, a solution or neat

liquid. Occasionally, however, a sample is in the vapor or gaseous phase is

investigated. Under this situation, in addition with alteration in vibrational energy,

meanwhile alteration in rotational energy can also observed and as a result few fine

structures may be found in the vibrational band. IR spectrum of a compound

represents its energy absorption pattern in the infrared region and is obtained by

plotting percentage absorbance or transmittance of infrared radiation as a function of

wavelength or wave number over a particular range.

Infrared spectroscopy is usually divided into three regions.

• Near infrared (overtone region) – between 12500cm-1-4000cm-1

• Middle infrared (fundamental vibrational region) – between 4000cm-1-

667cm-1

• Far infrared (pure rotational region) – between 667cm-1-50cm-1

The normal or middle infrared level is specifically meant for organic scientist

therefore the vibrations induced in organic compounds are absorbed within this level.

The fundamental vibrational area is divided into the functional group region (4000cm-

1-1400cm-1) and finger print region (1400cm-1-667cm-1). The normal and far infrared

regions contain absorptions due to fundamental harmonic and combination bands.

The use of linear-in-frequency instruments results in a considerable expansion

of the high frequency end of the infrared region, resulting in an increased ability to

2929

resolve bands and define their positions. The place of absorption observed in the band

is rapidly articulated in form of wave number (cm-1) with respect to absorbed light.

The IR spectrum is the easy, quicker & often more reliable resources for

interoperating a sample to its division. It can also give different information on purity,

symmetry, structure, geometrical and structural isomers & H- bonding.

2.3.1 Anticipated Infrared Frequencies for Heterocyclised products based on

NTOH.

The present thesis comprises the study of following heterocyclized products:

2-(3-flourophenyl)-1,2,4-[3,2-b]-triazolo-Odz-6-thione aceto hydrazide (NTOH)

b) Schiff Bases of AOD

c) 2-Azetidinones

d) 4-Thiazolidinones

e) 2H-Pyrrole-2-Ones

f) 2-Pyrrolidinones

Hence, prior to characterize these compounds by IR spectroscopy it is

necessary to predict the anticipated frequencies of each moiety.

2-(3-flourophenyl)-1,2,4-[3,2-b]-triazolo-Odz-6-thione (NTOH):

NTOH is a heterocyclic compound. It is an aromatic compound thus it

provides the IR frequencies. The bands due to oxadiazole are at 990-1190cm-1 and

1620-1640cm-1 corresponds to C-O-C (str.) and C=N groups. The weak band at 1040

cm-1 is because of N-N of oxadiazole ring. The other band because of aromatic

fragments at 4-place are found at their respective place.

Schiff Bases:

3030

Acyclic unsaturated nitrogen compounds containing C=N bond is most

commonly encountered in oximes and Schiff’s bases. Both the classes absorb in the

region from 1690-1640 cm-1, usually less strongly than carbonyl compounds but the

oximes are distinguished by the presence of O-H stretching(free) absorptions between

3650 and 3600 cm-1 in dilute solution.

2-Azetidinones (β-lactams):

Lactams exhibits the following characteristic absorption bands in their spectra.

Lactams exhibit a strong N-H stretching bonded absorption in the solid state closer to

3200 cm-1 and a weaker band closer 3100 cm-1 resulted due to the grouping of N-H in-

plane bending and C=O stretching absorptions [5,6]. The carbonyl stretching vibration

absorbs near 1650 cm-1 in six or seven membered rings as in the case of acyclic trans

structure. Lactams (five membered ring lactams) absorb near 1750-1700 cm-1.

Unfused β-lactams absorb at 1760-1730 cm-1 while β -lactams fused to unoxidized

thiazolidine rings absorbed at 1780-1710 cm-1 [7,8].

Carbon-Nitrogen symmetrical stretching, Nitrogen-Hydrogen in-plane and out

plane bending, and N-H wagging vibrations: Cyclic mono substituted amide shows

no band in the area from 1600-1500 cm-1 similar to the 1550 cm-1 Carbon-Nitrogen-

Hydrogen in-plane bending band in the trans structure. The in-plane bending vibration

absorbs at 1490-1440 cm-1 for cis N-H & the vibration at 1350 cm-1 C-N stretching

[9]. There is much less interaction between these modes compared to the trans form.

The broad band closer to 800 cm-1 is because of N-H out-of-plane bending (wagging)

vibration appears.

3131

4-Thiazolidinones:

The carbonyl stretching vibration absorbs near 1650 cm-1 in six or seven

membered rings as in the case of acyclic trans structure. Thiazolidinones absorbs at

1730-1700 cm-1[10].

2-Pyrrolidinones:

Carbonyl stretching vibration around 1750-1710 cm-1 because of C=O. the

absorption at 1410 cm-1 because of C-N stretching vibration. N-H stretching vibration

between 3200-2400 cm-1 for saturated heterocycles such as pyrrolidinones and

piperidines. Heterocyclic systems exhibit C-H stretching bands in the usual region

3100-3000 cm-1[11,12].

2H-Pyrrole-2-ones:

Carbonyl group found at stretching vibration 1620-1685 cm-1. The stretching

vibration at 1410 cm-1 due to absorption for Carbon-Nitrogen single pi-bond. In non-

polar solvents it shows a very strong N-H stretching absorption within 3500 & 3450

cm-1. Heterocyclic systems shows C-H stretching vibrations in usual region n 3100-

3000 cm-1. Band because of C=C of the ring stretching around 1615-1565 cm-1. N-H

in-plane bending found closer to 1146 cm-1 and out-of-plane bending is found closer

to 561 cm-1[11,12].

2.4 Proton NMR Spectroscopy

Nuclear resonance (NMR) spectrum analysis is supplementary technique to IR

spectrum analysis to urge details data concerning structure of organic Compounds.

most generally studied nucleus is nucleon and so the technique is named PMR

spectrum analysis [92-93].

IR spectra provide data concerning the purposeful cluster whereas magnetic resonance

spectra give data concerning the precise nature of nucleon and its atmosphere. so this

method is additional helpful within the elucidation of associate degree Comp.. IR

3232

spectra of isomers might seem same however their magnetic resonance spectra can

markedly disagree.

The development of nuclear resonance was 1st rumored severally in 1946. Block and

organist were discovered this innovation and therefore they was awarded in 1952 for

discovery in physics for this. Since from this point, the NMR techniques are widely

useful in chemistry, advance biology for complex structure determination.

The nucleon resonance (PMR) spectrometry is that the most significant technique

used for the characterization of organic Compounds. It gives the information

regarding the proton and give exact idea about the structure. In other words it tells one

regarding completely different forms of environments of the chemical element atoms

within the molecule. PMR also give useful information regarding arrangement of

proton in space, i.e stereochemistry.

It is accepted that each one nuclei carry a charge. Thus, the nucleus behaves sort of a

little magnet. The momentum of the spinning charge is delineating in terms of spin

range (I). The magnitude of generated dipole is expressed in terms of nuclear torque

(µ).

The spinning nucleus of a atom (1H or proton) is that the simplest and is often

encountered in organic Compounds. The chemical element nucleus includes a

twisting, δ= 2.79268 and its spin range (I) is + ½. Hence, in associate applied external

flux, its torque might have 2 attainable alignments.

The orientation within which the torque is aligned with the applied flux is a lot of

stable (lower energy) than within which the torque is aligned against the sector (high

energy). The energy needed for flipping the nucleon from its lower energy level to the

upper energy level depends upon the difference in energy (∆E) between the two

states.

The substance placed in a magnetic flux of constant strength, so the spectrum

obtained similar to infrared or associate spectrum. Those radiations is absorbed b y

passing radiation of different frequency through the substance and perceptive the

frequency. It was found to be a lot of convenient that radiation frequency constant and

vary the strength of the flux. At some worth of the sector strength the energy needed

to flip the nucleon matches the energy of the radiation, absorption happens. Such a

spectrum is named a nuclear resonance (NMR) spectrum.

3333

Nuclear resonance (NMR) spectrum analysis is supplementary technique to IR

spectrum analysis to urge details data concerning structure of organic Compounds.

most generally studied nucleus is nucleon and so the technique is named PMR

spectrum analysis.

IR spectra provide data concerning the purposeful cluster whereas magnetic resonance

spectra give data concerning the precise nature of nucleon and its atmosphere. so this

method is additional helpful within the elucidation of associate degree Comp.. IR

spectra of isomers might seem same however their magnetic resonance spectra can

markedly disagree.

The development of nuclear resonance was 1st rumored severally in 1946. Block and

organist were discovered this innovation and therefore they was awarded in 1952 for

discovery in physics for this. Since from this point, the NMR techniques are widely

useful in chemistry, advance biology for complex structure determination.

The nucleon resonance (PMR) spectrometry is that the most significant technique

used for the characterization of organic Compounds. It gives the information

regarding the

3434

proton and give exact idea about the structure. In other words it tells one regarding

completely different forms of environments of the chemical element atoms within the

molecule. PMR also give useful information regarding arrangement of proton in

space, i.e stereochemistry.

2.4.1 13C NMR spectroscopy

In a current era, most of the structure determinations of organic molecules are

performed by 13CMR spectroscopy. It is more powerful tool to determine the exact

geometry of molecules.

In contrast to 1H spectra, it is not possible to determine the relative ratio of carbon

atoms in a Comp. by integration of the peak areas in the 13C FT-NMR spectrum.

There are two reasons for this. The first result results from the different relaxation

times of carbon atoms in different environments. This means that some atoms with

long relaxation times may still be partly saturated when the next pulse of radiation is

received, and the resulting absorption peak areas will not be proportional to the

different environmental nature of carbon atom. C-H bonds have longer relaxation

times and are therefore likely to give rise to peaks of lower intensity in the spectrum.

The second reason is due to the Nuclear Overhauled Effect (NOE). This is the

enhancement of some signals in the 13C spectrum as a result of the spin-decoupling

process which is used to produce the normal, noise-decoupled spectrum by removing

the interaction between carbon and hydrogen nuclei. The NOE is not the same for all

nuclei. The maximum effect is for carbon atoms with hydrogen attached. The

consequence is that carbon atoms without hydrogen attached appear without any NOE

enhancement. As a result of these two effects, it is often possible to identify b y

inspection, as a result of their lower intensity, those peaks in the 13C spectrum which

result from carbon atoms not attached to hydrogen, including those in aromatic rings

which carry a substituent.

A considerable amount of the data is available which correlates the position of

absorptions in the 13C NMR spectrum with the structure of an organic molecule, and it

is these imperial correlations which provide the main basis for the use of the

technique in structure determination. The values for the chemical shifts are normally

related to the tetramethylsilane carbon absorption, with positive values increasing to

lower field (corresponding to the scale in PMR spectroscopy). The vast majorit y

3535

of absorptions fall in a range of 200 ppm between the carbonyl absorptions at low

field and the methyl absorptions at high field.

The orientation within which the torque is aligned with the applied flux is a lot of

stable (lower energy) than within which the torque is aligned against the sector (high

energy). The energy needed for flipping the nucleon from its lower energy level to the

upper energy level depends upon the difference in energy (∆E) between the two

states.

The substance placed in a magnetic flux of constant strength, so the spectrum

obtained similar to infrared or associate spectrum. Those radiations is absorbed b y

passing radiation of different frequency through the substance and perceptive the

frequency. It was found to be a lot of convenient that radiation frequency constant and

vary the strength of the flux. At some worth of the sector strength the energy needed

to flip the nucleon matches the energy of the radiation, absorption happens. Such a

spectrum is named a nuclear resonance (NMR) spectrum.

3636

2.5 Mass Spectroscopy

It is unlikely that the laboratory organic chemist will be required to record

mass spectra of compounds produced in the laboratory as they will normally be

obtained through a centralized service.

Probably the most common use of mass spectrometry by the organic chemist

is for the accurate determination of molecular weight. A second important use is to

provide information about the structure of compounds by an examination of the

fragmentation pattern.

2.6 General Remarks for the Experimental Techniques

� All the compounds were characterized in terms of Melting points (oC) by open

capillary method and were uncorrected.

� The yields of all compounds reported are of crystallized. All solvents used

were distilled and dried. The cleanliness of the sample was tested by TLC.

� C, H, N and S elemental analysis of all prepared compounds were recorded on

Thermofinigen 1101 Flash elemental analyzer.

� IR data were observed in KBr pellets on Nicolet 760D spectrophotometer.

� CMR and PMR spectra were found on Bruker NMR spectro-photometer.

� LC-MS of selected one sample of each series has been carried out on LC-

MSD Trap-SL 01046 instrument using CH3CN solvent.

3737

SECTION – II

SYNTHESIS AND CHARACTERIZATION OF VARIOUS SCHIFF BA SES OF

NTOH

3838

Theoritical consideration:

Organic chemists are frequently facing the problem of characterizing and

ultimately elucidating the structure of organic compounds. The worker in the region

of natural product has the prospects of isolating such compounds from their sources in

a pure state and then determining their structure. On the other hand the synthetic

organic chemist encounters new or unexpected compounds in the course of

investigations.

All the synthesized are also characterized by its melting point and meting points were

detected by melting point apparatus. All the MPs were uncorrected.

The yields of all Compoundsreported are of crystallized. All solvents used were

distilled and dried. TLC was carried out to determine purity of the Compounds.

Column chromatography technique was employed using silica of 60-120 mesh.

Elemental analysis of all the Compoundswere recorded on Thermofinigen 1101 Flash

elemental analyzer for determining content of C, H, N and S contents.

Infrared spectra were recorded on Nicolet 760 spectrophotometer by preparing KBr

pellets.

1H and 13C NMR were measured on Bruker avance 400 MHz instrument. Chemical

shifts were measured in ppm. Solvent peak were used as a internal standard.

LC-MS of selected one sample of each series has been carried out on LC-MSD Trap-

SL 01046 instrument using CH3CN solvent.

The reagents, the reaction and the conditions of the reaction system are given in the

following scheme 2.1 as follows,

2.7. Synthesis of 2-(5-((naphthalen-1-yloxy)methyl)-1,3,4-oxadiazol-2-thioxo-

3(2H)-yl) acetohydrazide (NTOH).

2-(5-((naphthalen-1-yloxy) methyl)- 1,3,4-oxadiazole-2-thioxo (A) were prepared

by method reported in literature [13].

2-(5-((naphthalen-1-yloxy) methyl)- 1,3,4-oxadiazole-2-thioxo- (A) (0.01 mole)

and 0.01 mole chloro acetic acid in acetone (5 ml) were taken in round bottom flask [100

ml]. Then charge K2CO3 (0.005 mole) and mixture were refluxed for 5-8 hrs. The

3939

solution was drinkable through celite bed and filtrate solution was distilled out to get

crude solid product. This is in turn purified by dissolving in methanol and pure

product fall out by adding water. Which in turn filtered and washed with water and

dried for 12 hrs. at 500-550 C.

The NH2OH (0.02 M), some drops of H2SO4 and title compound (0.01 mol) were

mixed in ethanol. All the liquid mass was refluxed for time mentioned. After the

completion of reaction the solid product was fall out and filtered and dried [14].

2.7.1 Synthesis of Schiff bases of 2-(5-((naphthalen-1- yloxy)methyl)- 1,3,4-

oxadiazol-2-thioxo--3(2H)-yl) acetohydrazide (NTOH). The Schiff bases of NTOH

were synthesized by method reported [15].

Benzaldehyde derivative (2a-h) (0.01mole), NTOH (0.01mole) and ethanol

(20ml) were taken in a beaker [100ml]. The mixture was heated until a pure solution

was obtained. The pure solution was kept overnight when respective Schiff base fall

out which was filtered, washed by petroleum ether and air dried. The resultant Schiff

bases are designated as 2a-h and their details are shown as follows.

4040

O S

O N NH

(A)

2-(5-((naphthalen-1-yloxy) methyl)-2-thioxo-1,3,4-oxadiazole

ClCH2COOH

NH2NH2

O

O N N

S CH2CONHNNH2

(1)

2-(5-((naphthalen-1-yloxy) methyl)-2-thioxo- 1,3,4-oxadiazol-3(2H)-yl) acetohydrazide (NTOH)

Ar-CHO

O

O N N

S CH2CONHN CH Ar

Schiff bases

(2a-h)

OH NO2

Where, Ar = , ,

CH3 OMe

, , , OH

, , O

N

H3C CH3

Scheme 2.1

4141

RESULTS:

2.8 Experimental:

The synthesis of Schiff base derivatives by the earlier described method

resulted in products with good yields.

Compound 2a

O

O N N

S CH2CONH N

N'-arylene-2-(5-((methyl-1-yloxy)naphthalen)-Odz-2-acetohydrazide-3(2H)-thioxoyl)

Molecular Formula : C22H18N4O3S Elemental Analysis

Molecular Weight : 418 %C %H %N %S

Physical state : Off white crystals Theoritical 63.15 4.30 13.39 7.65

Melting point : 152-1540C Found 63.65 4.40 14.50 8.05

Percentage Yield : 87%

Compound 2b

O

O S

N N CH2CONH N

CH3




Physical state : Off white crystals Theoritical 63.88 4.63 12.96 7.40



4242

Compound 2c

O

O N N

S CH2CONH N

OMe




Physical state : Light yellow crystals Theoritical 61.60 4.46 12.50 7.14



Compound 2d

O

O N N

S OH

CH2CONH N




Physical state : White crystals Theoritical 60.82 4.14 12.90 7.37



4343

Compound 2e

O

O

N N

S CH2CONH N

OH




Physical state : Brown crystals Theoritical 60.82 4.14 12.90 7.37



Compound 2f

O

O N N

S CH2CONH N

NO2







Compound 2g

4444

N

CH3

O

O N N

S CH2CONH N

CH3







Compound 2h

O

O N N

S

O CH2CONH N




Physical state : Light pink crystals Theoritical 58.82 3.92 13.72 7.84



4545

2.9 Characterization:

Compound 2a

O

O N N

S

CH2CONH N

Infrared Spectral Features in cm-1

3453 cm-1 N-H stretching of amide

1626 C=O stretching of CH2CONHN

1500 cm-1 stretching of C-H

1592 cm-1 stretching of CH=N

1H-NMR spectral Features (δ, ppm)

6.14-8.57 (m, Ar-H & Napthalene +

CH=N proton),

4.2 (s, 2H, OCH2)

2.93 (s, 2H, -CH2CONH)

Mass in m/z

Molecular ion peak was observed at 419.3

13C-NMR spectral Features (δ, ppm)

114-130 Benzene & naphthalene

114-165 oxadiazole

153 C=N

46

Fig. 2.1 IR Spectrum of Compound 2a

Fig. 2.2 1H-NMR Spectrum of Compound 2a

47

Fig. 2.3 13C-NMR Spectrum of 2a

48

Fig. 2.4 Mass Spectrum of 2a

49

Compound 2b

O

O N N

S CH2CONH N

CH3



1626 cm-1 C=O from CH2CONH

1500 cm-1 stretching of C-H

1592 cm-1 stretching of CH=N



CH=N proton)

4.2 (s, 2H, OCH2)

2.95 (s, 2H, -CH2CONH)

2.50 (s, 3H, CH3)

Mass in m/z




114-165 oxadiazole

153 C=N

50

51

Fig. 2.5 IR Spectrum of Compound 2b

2.6 1H-NMR Spectrum of 2b

52

Fig. 2.7 13C-NMR Spectrum of 2b

53

Fig. 2.8 Mass Spectrum of 2b

54

5555

Compound 2c

O

O

N N

S

C H 2 C O N H N

O M e


3453 cm-1 N-H of amide stretching

1626 cm-1 C=O of CH2CONH

1500 cm-1 C-H stretching

1592 cm-1 CH=N stretching

1250 cm-1 OCH3 stretching



CH=N proton),

2.95 (s, 2H, -CH2CONH)

4.20 (s, 2H, OCH2)

4.30 (s, 3H, OCH3)

Mass in m/z




114-160 oxadiazole

154 C=N

Compound 2d

O S O H

O N N

CH2 CONH N






3215 cm-1 OH stretching



CH=N proton),

11.2 (s, H, OH)

4.2 (s, 2H, OCH2)

2.98 (s, 2H, -CH2CONH)

Mass in m/z




114-160 oxadiazole

154 C=N

5656

Compound 2e

O S

O N N

CH2CONH N OH






3215 cm-1 OH stretching


11.2 (s, H, OH)


CH=N proton),

4.2 (s, 2H, OCH2)

2.92 (s, 2H, -CH2CONH)

Mass in m/z




114-160 oxadiazole

154 C=N

Compound 2f

O S

O N N

C H2 C O N H N

NO 2






2750 cm-1 N=O stretching of –NO2



CH=N proton)

4.23 (s, 2H, OCH2)

2.98 (s, 2H, -CH2CONH)

Mass in m/z




114-160 oxadiazole

154 C=N

Compound 2g

5757

C H3

O S N C H3

O N N

CH2 CO N H N






1050 cm-1 N-O stretching of –N-(CH3)2



CH=N proton)

4.25 (s, 2H, OCH2)

2.95 (s, 2H, -CH2CONH)

2.50 (s, 6H, -N(CH3)2 ) Mass in m/z




114-160 oxadiazole

154 C=N

Compound 2h

O S

O N N O

CH 2C ON H N






1592 cm-1 C=S stretching of ring



CH=N proton+ Furan)

4.2 (s, 2H, OCH2)

2.94 (s, 2H, -CH2CONH)

Mass in m/z




114-160 oxadiazole

154 C=N

5858

2.10 Results and Discussion:

All the Schiff bases of NTOH are in amorphous form and soluble in polar

organic solvents.

The C, H, N and S elemental of all the Schiff bases are found with the given

structures. The infrared spectral (Typical in Figs. 2.1 and 2.5) data are given in details

of each compound. All the spectra comprises the important IR spectral features of

aromatic, oxadiazole ring and –CH=N- group.

The 1H NMR spectra (Typical in Figs. 2.2 and 2.6) of all Schiff bases shows

the signal for aromatic proton and azo methine proton in the range of 6.1 to 6.8 δ

ppm.

While in 13C-NMR spectra (Typical in Figs. 2.3 to 2.7) signals are observed

which are in the region of 114 to 153 ppm. The assignment of signals is given

individually in each compound.

Finally LC-MS of one of samples spectrum shows peak of (m/z) is good

consistent with the theoretical molecular weight of 2a-h.

5959

References

1. Kemp, W, (1996) Organic Spectroscopy, ELBS.

2. Oteorge, B, (1972) Infrared Spectroscopy, Heyden, London.

3. Bellamy, L, J, (1980) The Infrared Spectra of Complex Molecules, Metheuen,

London.

4. Merck, E, (1987) FTIR Atlas, VCH-Verlag/Ischatt, Weinheim, Germany.

5. Griffith, P. R, (1956) FTIR Spectrometry, Wiley, Chichester.

6. Miyazawa, T, (1960) J. Mol. Spectr., 4, 168.

7. Clarke, M, T (ed.) (1949) “The chemistry of Penicillin”, p.390, Princeton

Press, Princeton, N. J.

8. Brockmann, H, (1956) Chem. Ber., 89, 241.

9. Miyazawa, T, (1960) ibid, 4, 155.

10. Dains, F. B, (1933) J. Am. Chem. Soc., 55, 3857.

11. Plieninger, H, (1956) Ann. Chem. Liebigs, 598, 198.

12. Schulte, K, E, (1960) Arch. Pharm., 293, 687.

13. Jaiswal, N, (2012) Int. research J. of pharmacy, 3(3).

14. Patel, P, and Gour, D, (2012) Int. J. Pharma. Science and research, 3(7),

2269.

15. Shah, R, R, and Mehta, R. D, (1985) J. Indian Chem. Soc., Vol. LXII, 255.

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