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ISSN: 2278-1862

Journal of Applicable Chemistry
2014, 3 (6): 2365-2371
(International Peer Reviewed Journal)
Simulation Study of alkylation reaction of resorcinol
Haifaa Adnan, Saadon Abdulla Aowda and Abbas A-Ali Drea*
*Chemistry Department, College of Science, Babylon University, Hilla, IRAQ
Email: aadreab22@yahoo.com
Accepted on 3
rd November 2014
_____________________________________________________________________________
ABSTRACT
Study of alkylation reaction of resorcinol has been carried out theoretically using semi-empirical methods
(PM3). Four transition states have been suggested and examined to check up the most probable transition
state that gives the most probable pathway of the reaction. Geometrical properties and vibration
spectrums have been calculated and compare with their practical spectra. Calculus indicate two transition
state which are most probable than other states due to its energetic values of total energy, binding energy,
heat of formation, zero point energy, and imaginary frequency that’s equal to -62727.105, -2661.13, -
200.104, 132.038 respectively by Kcal mol-1
units. The pathway of alkylation reaction is spontaneous and
exothermic with the change in Gibes energy value and heat of formation value equal to -62620.4 and -
200.104 Kcal mol-1
units respectively.
Keywords: Semi empirical calculations, transition state, resorcinol, alkylation Al2 (SiO3)3.
______________________________________________________________________________
INTRODUCTION
Resorcinol is one of the natural phenols in argon oil provided properties [1-3] and it’s used primarily in the
rubber industry for tires and reinforced rubber products (conveyer belts, driving belts) and high-quality
wood adhesives. It is also used in the preparation of dyes and pharmaceuticals, as a cross-linking agent for
neoprene and a rubber tackier [4].
Theoretical study to synthesis 1, 3, 5,-tri glycerol benzene using semi empirical and Ab-Initio calculation
methods. Calculus indicates hydroxyl group and hydrogen atom in glycerol molecules of secondary carbon
atom are more active than of primary carbon atom for esterification and alkylation reactions respectively.
Glycerol react efficiently with acetic acid in three steps to produced tri acetate glycerol through
endothermic reaction ?Hrea = 28.157 Kcal mol-1
. Alkylation reactions at aromatic ring take place through
controlling system of orientation to give up 1, 3, 5- Tri (glycerol tri acetate) benzene by endothermic
reaction ? ?Hrea = 8.967 Kcal mol-1
. 1, 3, 5-Tri glycerin benzene produced during hydrolysis the ester
derivative with nine mole of water molecule by exothermic reaction ?Hrea = -120.991 Kcal mol-1
. Large
electronic density occurs through new products for nine polar functional gropes of hydroxyl [5].
The oxidation reaction of Oleic acid has been carried out using semi-empirical methods (PM3 and AM1),
were the Geometrical properties and vibration spectrums have been calculated. Five different transition
Abbas A-Ali Drea et al Journal of Applicable Chemistry, 2014, 3 (6): 2365-2371
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states have been suggested and the most probable transition state been investigated depending upon the
electronic properties to suggest the most probable pathway of the reaction. The calculations prove that first
transition state is the most probable than other state due its energetic values of total energy, binding
energy, heat of formation, zero point energy, and imaginary frequency that’s equal to -111016.403, -
5670.849, -398.307, 314.119 respectively by Kcal mol-1
units .The pathway of reaction is spontaneous and
exothermic with the change in Gibes energy value and heat of formation value equal to -36122.691 and -
110745 respectively [6, 7].
In the present work, semi empirical calculation will be done to simulate the reaction of synthesis.
Alkylation of aromatics moieties is an important reaction in organic chemistry as it is widely used in the
synthesis of petrochemicals[8], fine chemicals, perfumeries, pharmaceuticals, dyes and agrochemicals The
alkylation process will done on the resorcinol using solid acid catalysts. Friedel–Crafts alkylation reaction
such as Al2(Sio3)3 will be used to give (2,4dihydroxyphynl )propane-1,2,3-triol ). In general, Friedel–Crafts
alkylation is carried out conventionally with the use of homogeneous Lewis and Br?nsted acid catalysts
[9,10]. Different transition states will be suggested to find the most probable transition state that’s can be
occur to give up the final product.
MATERIALS AND METHODS
Infrared spectra were performed using a Shimadzu (FT-IR) -8400S spectrophotometer in the range (4000-
400cm-1
). Spectra were recorded as potassium bromide discs[11] .Geometry optimization, electronic
energies, heat of formation and electrostatic potential energy of glycerol and resorcinol were performed by
theoretical calculations of semi-empirical method PM3 level, that’s implemented on packaged hyper
chem.8.0.9 program [12,13]. The highest occupied molecular orbital (HOMO) and the lowest unoccupied
molecular orbital (LUMO) were performed [14]. Energy gap (?E), bond lengths and the charge of atoms
[15]. Thermodynamic parameters (?G, ?H, ?S) have been estimated [16].
RESULTS AND DISCUSSION
Geometry optimization of resorcinol is calculated to estimate the reactivity and charge distribution. Figure
1. Show the structural properties of resorcinol. The negative charge densities are remarked by red color
and distribute on the Oxygen atoms in hydroxyl groups due to high value of electronegativity. The positive
charge densities are remarked by green color and distribute on the carbon atoms ,this behavior determine
the reactivity of phenyl ring toward the substitution reaction, especially when the reaction occurs between
different competitive configuration for the same final products[17] .
Atomic Ball view Atomic symbol
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Total charge density in two dimension Electrostatic potential in two dimension.
Figure 1. Geometrical properties of resorcinol calculated in two dimensions.
Alkylation reaction of resorcinol depending on the alkylation of glycerol in the presence of Aluminum
silicate as a catalyst, that’s occurs in two steps to produce some probable products. The calculus show two
probabilities only for the first step of alkylation reaction as shown in figure 2. The comparison between the
two probable configurations of alkylation reaction, first probable occurs on primary hydrogen of carbon
atom. Second probable occurs on secondary hydrogen of carbon atom at the glycerol molecules [18]. This
probable is dominate in the transition state formation of the reaction due the lowest energy value of the
reaction barrier (40.51 Kcal mol-1
) than first probable energy value(130.93 Kcal mol-1
) in the forward
reaction of transition state formation. Different four transition states of alkylation reaction have been
examined to suggest the estimate probable transition state, that’s give product of alkylation as shown in
figure 3.
The first probable of alkylation reaction.
The second probable of alkylation reaction.
Figure 2. The probabilities of transition state formation for the first step of alkylation reaction.
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The orientation of electrophilic attachment reagent (positive carbon ion) have four probabilities on the
aromatic ring of resorcinol, due they found two hydroxyl groups. The stable conformation of alkylation
products depend on electronic density distribution that’s occurs by resonance of ring. The second
suggested transition state provided good estimation about the alkylation occurs at this active site by its
numerical values of structural properties, that’s show in in table 1.
Figure 3.The geometrical suggested transition state for alkylation reaction
calculated by PM3-semi empirical method.
Table1. Show that compares in energetic properties of transition state for alkylation product formation.
According to First imaginary frequency and zero point energy, the suggested second transition state TS2
represent the actual state of alkylation reaction. The catalyst molecule (Al2(SIO3)3) is joined to bond of
resorcinol to give(2-(2,4dihydroxyphynyl )propane-1,2,3-triol ) as transited product , which is exothermic
and spontaneous reaction with ?H and ?G equal to 200.104 and -62620.4 respectively with energy gap
equal to 9.285 Kcal mol-1
[19]. Also the lowest energy barrier value related to TS2. The second transition
state is the real transition state because it has the lowest potential energy surface value of formation and
highest zero point energy (ZPE) value than other states.
TS1 TS2
TS3 TS4
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Table 1. Energetic properties of transition states for alkylation product formation in Kcal mol-1
units.
imaginary
frequency Z.P.E
?H
°
Binding Energy reaction Total Energy TS
TS1 -62903.998 -2536.550 -23.419 134.861 +
TS2 -62908.800 -2539.325 -26.221 136.665 _
TS3 -62886.80 -2519.35 -6.221 135.829 +
TS4 -62907.852 -100.25 -27.272 136.407 _
Figure 4. Show the structural geometry of alkylation product, that’s nomenclature is 2, 4-dihydroxyphynylpropane-1,
2, 3-triol. The compares of vibrational spectrum analysis between calculated spectrum and
practical showing identical signals in the most vibration mods, that’s indicate they found closer estimation
of calculus with real products.

Figure 4. Structural geometry view of 2, 4-dihydroxyphynl-propane-1, 2, 3-triol.
Figure 5. Show that the real vibrational spectrum analysis of (2, 4-dihydroxyphynyl) propane-1, 2, 3-triol.
The identical results between practical and estimation indicate that substitute of secondary carbon atom of
glycerol moiety on the carbon of aromatic ring. Table 2. Show vibration spectrum analysis of (2, 4-
dihydroxyphynyl) propane-1, 2, 3-triol for the real state and estimation.
.
Figure 5. Vibrational spectrum analysis of (2, 4-dihydroxyphynl) propane-1, 2, 3-triol.
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Table 2. Vibration spectrum analysis of (2, 4-dihydroxyphynl) propane-1, 2, 3-triol.
Intensity Descriptions Theoretical
Frequency cm-1
Experimental
Frequency cm-1
3284.88 3350.20 50.303 O-H broad stretch aromatic
? C-H stretch aromatic
Asymmetry 2941.54 3066, 3056 12.413, 25.901
1600.97 1607 28.657 ? C=C sharp stretch aromatic
1489.10 1487.62 20.23 C-H sharp stretch?
1475 1475.70 17.132 C-H?
1415.80 1409.62 30.768 C-H starching ?
1278.85 1276.51 33.165 C-O?
1215.19 1254 30.803 C-C?
1166.97 1194 13.759 ? C-H bending
960 934.38 24.904 C-H sharp bending?
840 842.05 12.319 C=C-C ring aromatic
APPLICATIONS
Estimation study through semi empirical (PM3) is useful proofing of alkylation reaction of resorcinol with
glycerol through calculation results of modulation before synthesis is taken out in laboratory.
CONCLUSIONS
? Alkylation reaction of resorcinol depending on the alkylation of glycerol in the presence of
Aluminum silicate as a catalyst.
? Two suggested transition states which are dominate in alkylation reaction only of resorcinol and the
second state is more preferable than other due energetic properties.
? The catalyst molecule (Al2(SIO3)3) is joined to bond of resorcinol to give(2-(2,4dihydroxyphynl )
propane-1,2,3-triol) as transited product.
? Alkylation reaction of resorcinol occurs through secondary carbon atom of glycerol.
REFERENCES
[1] Z. Charrouf and D. Guillaume, American Journal of Food Technology, 2007, 2, 679-683.
[2] S. Budavari, ed The Merck Index, 12th Ed., Whitehouse Station, NJ, Merck & Co.1996, p. 1402.
[3] D.R. Lide, ed CRC Handbook of Chemistry and Physics, 78th Ed., Boca Raton, FL, CRC Press,
1997, pp. 3-43.
[4] R.J. Lewis, Jr Hawley’s Condensed Chemical Dictionary, 12th Ed., New York, Van Nostr and
Reinhold, 1993, p. 1003.
[5] Abbas A-Ali Drea, National Journal of Chemistry, 2010, 39, 481-498.
[6] Doaa Muayad, Saadon Abdulla Aowda and Abbas A-Ali Drea, Journal of Babylon
University/Pure and Applied Sciences, 2012, 22(1), 110-119.
Abbas A-Ali Drea et al Journal of Applicable Chemistry, 2014, 3 (6): 2365-2371
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www. joac.info
[7] Doaa Muayad, Saadon Abdulla Aowda and Abbas A-Ali Drea, Journal of Applicable Chemistry,
2013, 2 (1), 42-49.
[8] S. Narayanan, K.V.V.S.B.S.R. Murthy, Appl. Catal., A, 2001, 213, 273.
[9] G. Sartori, and R. Maggi, Advances in Friedel-Crafts Acylation Reactions: Catalytic and Green
Processes, CRC Press, 2009
[10] N.E. Poh, H. Nur, M.N.M. Muhid, H. Hamdan, Catal. Today, 2006, 114, 257.
[11] G. Marc Loudon, Organic Chemistry, 4th Ed, Oxford University Press, Inc, 2002.
[12] HSD, Hazardous Substances Data Bank. National Library of Medicine, Bethesda, MD (TOMES®
CD-ROM Version). Denver, CO: Micromedex, Inc.1995.
[13] Bahjat R. J. Muhyedeen and Abbas A-Ali Drea, Journal of Multifunctional Materials and
Photoscience, 2014, 5(1), 1-19.
[14] Fadhel Omran Essa, Kadhum Jwad Kadhum and Abbas A-Ali Drea Journal of Applicable
Chemistry, 2012, 1 (1), 125-136.
[15] Abbas.A-Ali Drea, Salah A.Naman and Bhjat R.Jaffer, Journal of Applicable Chemistry, 2012, 1
(3), 344-351.
[16] Mohamed H. Obies, Abbas A-Ali Drea and Falah H. Hussein, Int. J. Chem. Sci., 2012, 10(1),63-
79.
[17] Abbas A- Ali Drea and Nadia Izet. Journal of photocatalysis science, 2012, 3(2), 49-59.
[18] Aqeel A-Hussein and Abbas A-Ali Drea, Journal of Applicable Chemistry, 2012. 1(2), 319-329.
[19] Abbas.A-Ali Drea, Salah A.Naman and Bhjat R.Jaffer, Iraqi National Journal of Chemistry, 2011,
44, 539- 560.