La-Mg mixed oxide as a highly basic water resistant catalyst for utilization of CO2 in the synthesis of quinazoline-2,4(1H,3H)-dione

Article abstract of DOI:10.1039/c6ra15802a

The synthesis of quinazoline-2,4(1H,3H)-dione was done by direct utilization of CO₂ in the cyclization of 2-aminobenzonitrile (2-ABN) using lanthanum magnesia mixed oxide (La-Mg MO) as a strong basic catalyst under mild reaction conditions in water. It gave a conversion of ～92% with 100% selectivity at 140 °C in 14 h. La-Mg MO was prepared by hydrothermal method using urea as homogeneous precipitating agent. The catalyst was characterized by different analytical techniques like BET, XRD, FT-IR, SEM, and TGA, and the basicity by CO₂-TPD and acidity by NH₃ TPD. Various reaction parameters were studied to predict the reaction mechanism and kinetics. The reaction follows the Langmuir-Hinshelwood-Hougen-Watson (LHHW) type kinetics model with an apparent activation energy of 23.3 kcal mol^-1. The catalyst was recycled three times with an insignificant change in activity. The overall process is clean and green.

Full text of DOI:10.1039/c6ra15802a

View Article Online
View Journal
RSC Advances
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: K. B. Rasal and G.
D. Yadav, RSC Adv., 2016, DOI: 10.1039/C6RA15802A.
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
Accepted Manuscripts are published online shortly after
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. We will replace this Accepted Manuscript with the edited
and formatted Advance Article as soon as it is available.
You can find more information about Accepted Manuscripts in the
author guidelines.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the ethical guidelines, outlined
in our author and reviewer resource centre, still apply. In no
event shall the Royal Society of Chemistry be held responsible
for any errors or omissions in this Accepted Manuscript or any
consequences arising from the use of any information it contains.
rsc.li/rsc-advances

Please do not adjust margins
RSC Advances
Page 1 of 13
View Article Online
DOI: 10.1039/C6RA15802A
RSC Advances
ARTICLE
La-Mg mixed oxide as highly basic water resistant catalyst for
utilization of CO in the synthesis of quinazoline-2,4(1H,3H)-dione
2
Received 00th January 2016,
Accepted 00th January 2016
Kalidas B. Rasal, Ganapati D. Yadav*
DOI: 10.1039/x0xx00000x
Synthesis of quinazoline-2,4(1H,3H)-dione was done by direct utilization of CO2 in cyclization with 2-aminobenzonitrile
using
www.rsc.org/
lanthanum magnesia mixed oxide (La-Mg MO) as a strong basic catalyst under mild reaction conditions in water. It gave
conversion ~ 92 % with 100 % selectivity at 140 °C in 14 h. La-Mg MO was prepared by hydrothermal method using urea as
a homogeneous precipitating agent. The catalyst was characterized by different analytical techniques like BET, XRD, FT-IR,
SEM, TGA and basicity by CO2-TPD and acidity by NH3 TPD. Various reaction parameters were studied to predict reaction
mechanism and kinetics. The reaction follows the Langmuir-Hinshelwood Hougen-Watson (LHHW) type kinetic model with
apparent activation energy (18.3 kcal/mol). The catalyst was recycled for three times with an insignificant change in
activity.
2
reversible IL (DBU based), [Bmim]Ac, DBU, guanidine
7
28
29
3
0
31
Introduction
2
base, DBU as catalyst in ScCO (solvent and reactant), N-
3
2
33
heterocyclic carbene (NHC) with K
2
CO
3
and CsCO
3
,
were
Global warming is the outcome of anthropogenic emission of
greenhouse gasses. The recent reports show the main reason
reported. These methods have common drawbacks like the
use of organic solvents, low atom economy and use of costlier
reagents.
for increasing CO
1
burning fossil fuel). CO
2
level is the increasing energy demand (i.e.
,2
2
is abundantly available, non-toxic,
3
4
3
,4
Recently, Ma et.al. developed catalyst free synthesis of
quinazolinedione in water, (160°C, 14 MPa of CO pressure for
1 h) it works at harsh reaction condition. To overcome these
difficulties herein, we report the comparatively simple
,10 synthesis of quinazolinedione in water using lanthanum
non-flammable, a renewable carbon source and so on. CO2
utilization as the C1 source is an elegant approach to
synthesize several value-added chemicals like methanol,
2
2
5
–8
formic acid, DMC, syngas, etc.
Also provides the best
9
alternative to highly toxic carbon monoxide and phosgene.
1
1
magnesia mixed oxide (La-Mg MO) as catalyst (Scheme 1). La-
CO2 is utilized for the synthesis of organic carbonates,
1
reduction to hydrocarbon,
1
methane reforming.
2,13
14
carbonylation reactions and
Mg MO was previously used as strong base catalyst in
3
synthesis of cyclic carbonate, Wittig reaction and aldol
5
36
5
3
7
reaction.
In CO utilization pathways, the main challenge is activation of
CO due to its low reactivity. In this perspective, we report the
Quinazoline-2,4(1H,3H)-dione (quinazolinedione) and its
derivatives are conversably used as key building blocks in the
pharmaceutical industry for the synthesis of antihypertensive,
2
2
1
6
use of La-Mg MO as a basic catalyst in the synthesis of
quinazolinedione using water as a solvent. The catalyst was
previously characterized by different analytical techniques;
antidiabetics, heart disease and other important medicines.
The green chemistry point of view synthesis of
quinazolinedione using CO as a C1 source has achieved great
2
2 3
XRD, FT-IR, CO and NH -TPD, BET surface area and TGA before
importance. Several heterogeneous catalytic systems were
developed to synthesize quinazolinedione using 2-
and after use. The reaction mechanism and kinetics were
studied.
aminobenzonitrile (2ABN) and CO as common starting
2
1
7
18
materials such as; MgO/ZrO , tungsten oxide, mesoporous
2
O
1
9
20
La-Mg 0.02 % w/v
CN
smectites,
amine fictionalize MCM-41,
[Hmim]OH
and amide
3
.5 MPa CO2
2
supported on SiO2, TBD supported on Fe O
1
22
NH
3
4
CO2
2
supported on the polymer. Also ionic liquids and organic
3
water,140°C
NH
2
14 h
N
O
2
4
25
+
-
bases such as; [Bmim]OH, [TBP][Arg], [HDBU ][TFE ],
26
H
2
Scheme 1: Synthesis of quinazolinedione by coupling of 2ABN and CO .
This journal is © The Royal Society of Chemistry 2016
RSC Adv., 2016, 00, 1-3 | 1
Please do not adjust margins

Please do not adjust margins
RSC Advances
Page 2 of 13
View Article Online
DOI: 10.1039/C6RA15802A
ARTICLE
Journal Name
Table 1: Literature review for synthesis of Quinazoline-2,4(1H,3H)-diones
Sr.
no.
1
solvent
solventless
Catalyst used
Temp. (°C)
Time (h)
CO2 Pressure
(MPa)
% conversion
Reference no.
ReIL
40
15
18
0.1
98
90
27
24
2
solventless
[Bmim]OH
120
3.0
3
4
solventless
solventless
[HDBU][TFE]
[Bmim]Ac
30
90
24
10
0.1
0.1
97
92
26
28
5
6
DMF
DMF
MgO/ZrO
2
130
140
12
16
3.7
4.0
92
64
17
22
TBD@Fe O
3
4
7
8
9
DMF
DMF
DMF
DMSO
DBU, DBN (3 eq. base)
Mesoporous smectites
[TBP][Arg]
20
24
6
0.1
4.0
8.5
0.1
97
68
92
95
29
19
25
32
130
100
120
12
15
1
0
NHC, K
2 3
CO
1
1
1
2
NMP
TBA [WO
2
4
]
140
80
24
4
2.0
10
91
89
18
31
ScCO2
DBU (0.05 eq.)
-
1
1
1
3
4
5
Water
Water
Water
160
130
140
21
18
14
14
3.5
3.5
92
91
92
34
20
Amine functionalize MCM-41
La-Mg Mixed oxide
Current work
Catalyst characterization
XRD
Results and discussion
XRD patterns of catalysts were analyzed in the range of 10°-75°
2θ value. La , MgO, and La-Mg mixed oxide catalysts show
sharp peaks (Figure 1). The peaks observed at a 2θ value of
5.21°, 30.54°, 46.34° and 55.76° are due to (100), (101), (110)
and (201) planes of La CO and La , respectively (JCPDS
La-Mg MO
3
6
2 3
O
Kantam et.al. reported that La-Mg MO of 1:3 molar ratio
La:Mg) shows the highest basicity. Conventionally, La-Mg MO
was synthesized by co-precipitation method at constant pH (9-
(
2
2
O
2
3
2 3
O
1
0) using nitrate precursors and NaOH or ammonia as
3
47
6,38
card # 49-0981). The peaks observed 2θ at 42.3 and 62.4
precipitating agent.
We prepared La-Mg MO with the
confirm the crystalline phase of MgO (JCPDS data card # 45-
48
hydrothermal method, using urea hydrolysis as a source
ammonia.
9
46).
In case of La-Mg MO peaks related to the different phases of
La and La CO are clearly observed and MgO phases are
Role of urea in synthesis of La-Mg MO
2
O
3
2
O
2
3
4
9,50
The urea hydrolysis technique used to get mono-dispersed
9–42
nano-sized metal oxides.
nearly disappeared.
lanthanum on MgO.
Thus, it shows well dispersion of
3
In this method controlled
hydrolysis of urea supplies ammonium hydroxide and
carbonate at decomposition temperature of urea, which
promotes the precipitation of metal ion to hydroxides,
4
3
carbonates, and oxyarbonates with uniform size. The metal
nitrate to urea mole ratio was studied in a range of 1 : 0.5 to 1
:
4. It was found that the surface area of La-Mg MO increases
significantly from 1 : 0.5 to 1 : 2 and thereafter decreases with
increase in urea concentration. So, the concentration of urea
has significant effect on the surface properties of the catalyst,
which is studied by BET surface area analysis. The 1:2 (nitrate:
2
urea) shows highest surface area (78.25 m /g) (Table-1). The
pH value substantially increases with increase in urea
concentration. Therefore at a lower concentration of urea,
4
4,45
there was incomplete precipitation.
At higher pH the
nucleation process of the metal hydroxide is very high. Due to
more concentration of ammonium hydroxide, the nuclei of
-
metal hydroxide and OH ions get attracted to each other with
2 3
Figure 1: X- ray diffraction pattern of (a) La-Mg mixed oxide (b) MgO and (c) La O
hydrogen bonding. The strong hydrogen bonding is responsible
for formation of agglomeration in metal hydroxide particles,
4
6
which results in low surface area of catalyst.
2
| RSC. Adv., 2016, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 3 of 13
Journal Name
PleaseRd So Cn oA t da vd aj un s ct ems argins
View Article Online
DOI: 10.1039/C6RA15802A
ARTICLE
2
The reused catalyst does not show any significant change in La
2 3
O and MgO are 19.3 and 99.2 m /g, respectively whereas
2
XRD patterns even after third reuse (ESI† Figure S3). It La-Mg MO shows 78.2 m /g. The increase in surface area of La-
confirms the structural stability of the catalyst.
Mg MO shows the dispersion of lanthanum on the surface of
MgO.
Morphology of catalyst (SEM)
Acidity and basicity of catalyst
Pure La shows nanocluster formation due to agglomeration
2
O
3
CO
basicity and acidity of catalysts, respectively. La-Mg MO shows
.78 mmol/g and pure La O shows 0.28 mmol/g, the surface
2 3
and NH -TPD analyses were performed to measure
2 3
of La O nanoparticles. La-Mg mixed oxide forms a dendritic
and spherical like structure and MgO show spherical structure.
The reused catalyst shows a change in morphology due partial
0
2
3
area of La-Mg MO increase significantly due to well the
51
rehydration (memory effect) in the reaction (Figure 2)
.
dispersion of La O on MgO (Table 1). According to the
2
3
5
previous published report, the CO desorption was divided
2
2
into three regions, i.e. weak basic (50 to 150°C), moderately
basic (200 to 400°C) and strong basic (more than 400°C). The
CO TPD of catalyst shows two desorption peaks at 198 and
2
3
47°C. The desorption of peak associated with 198°C shows
weak basic sites (0.37 mmol/g) and peak at 347°C attributed to
the desorption of CO2 from moderately basic sites (0.41
mmol/g). The NH -TPD of La-Mg MO shows the mild acidity
3
(
0.18 mmol/g). The reused La-Mg MO shows nearly the same
basicity (0.73 mmol/g) as compared to fresh catalyst.
FT-IR
-1
Figure 3 shows absorbance bands at about 642 and 450 cm
which are related to lattice vibration modes due to La-O bond.
-1
The band at 1085 cm is weak but sharp and observed due to
-
2
symmetric (CO ) . Weak bands are seen at 1750 and 1832 cm
-
3
1
-1
The 1750 cm may be due to carbonyl group of carbonate
.
Figure.2: SEM images of (a) La
2 3
O , (b) La-Mg MO and (c) MgO and (d) reused La-Mg MO and
-
1
1
832 cm due to bridged carbonate containing metal-oxygen
0
bond.
5
-1
The peak observed at 642 and 450 cm which are
BET surface area
related to lattice vibration due to La-O bond. The individual FT-
La-Mg MO shows the type IV adsorption isotherm
corresponding to the mesoporous structure. La-Mg MO (1:2;
nitrate: urea ratio) shows high surface area compared to other
ratios as described above (Table 1). The surface area of pure
IR
spectra
provided
in
ESI.
Table 2: surface area, pore size, pore volume and basicity of catalyst
Sr.
no.
nitrate to urea
mole ratio
CO
(mmol/g)
2
TPD
surface area
(m /g)
pore volume
(cm /g)
pH of supernatant
water
catalyst
2
pore size (nm)
3
1
2
3
La-Mg MO
La-Mg MO
La-Mg MO
1:0.5
1:1
0.29
28.6
52.3
78.2
7.8
8.5
8.7
0.21
0.25
0.24
8.0
8.5
9.6
0.45
1:2
0.79
4
5
6
7
8
9
La-Mg MO
La-Mg MO
1:3
1:4
1:2
1:2
-
0.56
0.36
0.29
0.39
0.52
0.73
62.4
51.2
19.3
99.2
37.2
73.5
9.8
11.9
24.0
6.9
0.11
0.10
0.12
0.17
0.23
0.21
10.5
11.8
La
2
O
3
-
-
-
-
MgO
La:Mg (co-ppt)
La:Mg (reuse)
12.1
7.9
1:2
This journal is © The Royal Society of Chemistry 20xx
RSC. Adv., 2016, 00, 1-3 | 3
Please do not adjust margins

Please do not adjust margins
RSC Advances
Page 4 of 13
View Article Online
DOI: 10.1039/C6RA15802A
ARTICLE
Journal Name
Due to MgO, the peak observed for Mg 2s at 89.3 and 88.9 eV
for fresh and reused catalyst, respectively. The peak observed
5
6
at 1304 eV due to MgO in both fresh and reused catalyst.
Figure 3: FT-IR of fresh and reused La-Mg mixed oxide
0
200
400
600
800
1000
1200
TGA
Binding energy (eV)
Thermal stability of calcined, uncalcined and reused La-Mg MO
(
without calcined) catalysts were studied by TGA (Figure 4)
.
Figure 5: Survey spectra of La-Mg Mo
Fresh La-Mg MO does not show a considerable loss in weight,
due to the formation of stable oxide form. The reused and
uncalcined La-Mg MO shows nearly the same TGA curve that
5
3,54
indicates that La-Mg MO shows memory effect like LDH.
In
uncalcined and reused La-Mg MO shows that 1-2 % loss in
weight due to a loss of water (humidity) at 100°C. 5-6 % Loss at
320 to 380°C indicates that decomposition of metal
oxycarbonates and evolution of CO to get stable oxide forms.
2
5
5
The carbonate content of reused catalyst is 6-7 %. Thereafter
there is no significant loss in weight which shows the
formation of stable oxide forms.
Figure 6: XPS of La-Mg MO; (a), (b) and (c), (d) XPS spectra of Mg 2s and La 3d3/2 fresh
and reused catalyst, respectively.
Reaction parameter study
Catalyst screening
The prepared catalyst was studied for its activity in utilisation
of CO in quinazolinedione synthesis. It was shown in Table 3
2
.
La-Mg MO (hydrothermal method) gives good conversion as
compared to MgO, La O and La-Mg by co-precipitation
2
3
Figure. 4: TGA of La-Mg MO (a) calcined, (b) uncalcined and (c) reused catalyst
method.
Table 3: Catalyst screening study
XPS
catalyst used
% conversion
28.2
Figures 5 and
6 show the XPS spectra of fresh and reused La-
Mg MO. The survey spectra show signals for La and Mg. For La O (commercial)
La O it shows high-resolution La 3d and La 3d3/2, XPS peaks
2
3
2
3
5/2
2
La O
3
46.2
observed at 835.37 and 852.41 eV with a spin-orbit splitting
MgO
28.4
17.02 eV and for reused La-Mg MO spin-orbital splitting is
7.56 eV. Splitting of La 3d5/2 attributes to the formation of
La-Mg MO (hydrothermal)
92.1
1
hydroxide and BE is 835.41 indicates formation of carbonate La-Mg MO (co-ppt)
phase in the catalyst. This is observed due to adsorption
76.8
moisture and atmospheric CO on the surface of the catalyst. A
2
sharp O 1s was observed at 530.1 eV as prepared the samples. CO pressure study
2
4
| RSC. Adv., 2016, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 5 of 13
Journal Name
PleaseRd So Cn oA t da vd aj un s ct ems argins
View Article Online
DOI: 10.1039/C6RA15802A
ARTICLE
CO
its influence on the conversion of quinazolinedione. CO
pressure increases H CO concentration in water so there is a
2
pressure was varied in a range of 0.5 to 4.5 MPa to study Effect of catalyst loading
3
2
Catalyst loading was studied in the range of 0.01 to 0.03 g/cm
2
3
w.r.t. reaction volume, keeping all other reaction conditions
3
constant (Figure 9). Up to 0.02 g/cm of catalyst loading, there
significant increase in conversion with an increase in pressure
up to 3.5 MPa. Thereafter, the conversion is nearly the same
was a significant increase in conversion due to proportionally
increase in active sites of catalyst available for reaction.
3,
However, after 0.02 g/cm there are no significant increases in
with an increase in CO
system is three-phase i.e. gas (CO
and solid (catalyst). Since the CO
2
pressure (Figure 7). It is due to, this
2
), liquid (water as solvent)
pressure was maintained
2
conversion. It is due to the availability of more active sites for
reaction. Hence, even increase in catalyst loading from 0.02
3
g/cm the conversion does not increase with catalyst loading.
throughout the reaction, so the concentration of H
remains constant. There is an equilibrium in between CO
water, so transfer of H CO to the catalyst surface for its
The concentration of H CO is much higher than
2
CO
3
2
and
2
3
5
7–59
activation.
2
3
100
required after 3.5 MPa pressure, which was adsorbed on the
surface of the catalyst, therefore no significant change in
8
6
4
2
0
0
0
0
0
6
0
conversion was observed at a constant temperature. Also, at
high CO pressure the equilibrium of adoption and desorption
of reactant and product may get disturbed.
2
1
00
8
6
4
2
0
0
0
0
0
0
2
4
6
8
10
0.03
12
14
Time (h)
0
.01
0.02
Figure.9: Effect of catalyst loading on synthesis of quinazolinedione; Reaction
conditions: 2ABN (5 mmol), reaction time (14 h), CO2 pressure (3.5 MPa), reaction
temperature (140°C), 30 mL water
Effect of initial concentration of 2ABN
0
.5
1.5
2.5
3.5
4.5
CO pressure (MPa)
The initial concentration of 2ABN was varied from 0.1 to 0.2
mmol/cm keeping all other reaction parameters constant
2
3
Figure 7: Effect of pressure on synthesis of quinazolinedione; Reaction conditions:2-
ABN (5 mmol), La-Mg MO (0.02 % (w/v), reaction time (14 h), reaction temperature
(
Figure 10). With this decrease in concentration the rate of
(
140°C), 30 mL water
3
reaction increases linearly up to 0.16 mmol/cm , thereafter
there is no significant increase in the rate of reaction. However,
with 0.16 mmol/cm , we got good conversion hence it has been
Speed of agitation
3
A speed range from 800 to 1000 rpm was studied for mass selected for further study.
transfer resistance. After 1000 rpm the conversion is
practically same. It confirms that there is no mass transfer
resistance effect after 1000 rpm conversion. Hence, 1000 rpm
was chosen to completely remove mass transfer resistance
100
8
6
0
0
(Figure 8)
1
00
80
60
40
20
0
40
2
0
0
0
2
4
6
8
10
12
14
Time (h)
0
0
.10 mmol/cm3
.16 mmol/cm3
0.13 mmol/cm3
0.20 mmol/cm3
0
2
4
6
8
10
12
14
Time (h)
Figure 8: Speed of agitation for synthesis of quinazolinedione; Reaction conditions:
ABN (5 mmol), La-Mg MO (0.02% (w/v)), CO2 pressure (3.5 MPa), reaction time (14 h),
Figure10: Effect of initial moles of 2ABN on the synthesis of quinazolinedione; Reaction
conditions: CO2 pressure (3.5 MPa), La-Mg MO (0.02% (w/v)), reaction temp. (140°C),
reaction time (14 h), 30 mL water
2
reaction temperature (140°C), 30 mL water
This journal is © The Royal Society of Chemistry 20xx
RSC. Adv., 2016, 00, 1-3 | 5
Please do not adjust margins

Please do not adjust margins
RSC Advances
Page 6 of 13
View Article Online
DOI: 10.1039/C6RA15802A
ARTICLE
Journal Name
Effect of temperature
1.4
y = 0.2202x
R² = 0.9946
Effect of temperature on the rate of reaction was studied from
20 to 150°C. The rate of reaction increases substantially with
1.2
1
y = 0.2183x
R² = 0.9939
increases with temperature which show that the reaction is
kinetically controlled. (Figure 11). The detailed study discusses
again in kinetics part.
1
0.8
0.6
0.4
y = 0.2139x
R² = 0.9938
1.6
1.2
0.8
0.4
0
y = 0.3695x
R² = 0.9912
y = 0.2076x
R² = 0.9962
y = 0.2231x
R² = 0.9928
0.2
0
y = 0.1229x
R² = 0.9965
0
2
4
6
8
Time (h)
y = 0.0729x
R² = 0.9986
Fresh
Frist reuse
second reuse
third reuse
Figure.12. Reusability of the La-Mg Mixed oxide for the synthesis of quinazolinedione;
Reaction conditions: 2-ABN (5 mmol), CO pressure (3.5 MPa), La-Mg MO (0.02%
2
(w/v)), reaction time (14 h), reaction temp. (140°C), 30 mL water solvent
Time (h)
0
2
4
6
3
93°K
403°K
413°K
Table 4: initial rates for reusability of La-Mg MO
Figure11: Plot of ln(1-X
A
) vs time (h)
Rate constants
Catalyst La-Mg MO
(lit/g cat/atm/h)
Reusability of catalyst
Fresh
0.2202
After completion of reaction the reaction mass was filtered
and the catalyst was washed 3-4 times with methanol to
remove adsorbed 2ABN and quinazolinedione. Then it was
dried at 105°C for 12 h. The reusability of catalyst was studied
for three cycles. The initial rate constants of cyclization of
Frist reuse
Sec. reuse
Third reuse
0.2183
0.2139
0.2076
2
ABN and CO
values are comparably same, indicates that catalyst is
reusable. The % conversion vs time was shown in Figure 12
2
was calculated (Table 4). The rate constant
Substrate study of 2ABN
The optimized reaction conditions were used to extend the
.
scope of reaction with CO using La-Mg MO as a catalyst.
2
Reused catalyst was well characterized by common analytical
techniques. Reused catalyst shows slight changes in surface
area, pore size, pore volume and basicity of the catalyst
Substrate with different electron--donating and withdrawing
group were studied (Table 5). 2ABN derivatives with an
electron-withdrawing group (-NO , -Cl and -F) give higher
2
(
Table-2).
conversion as compared to electron-donating groups (-CH and
3
For reusability study, the leaching test of catalyst was
performed to check leaching La-Mg MO catalyst. It was
-OMe).
2 3
observed that; 5.8 ppm and 1.8 ppm of MgO and La O
leaching, respectively. In water La and Mg oxides get
hydrolyse, thus there is slight leaching was observed during
the course of the reaction. The leaching is very less because
2 3
the MgO and La O phase have very less solubility in water.
6
| RSC. Adv., 2016, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 7 of 13
PleaseRd So Cn oA t da vd aj un s ct ems argins
View Article Online
DOI: 10.1039/C6RA15802A
Journal Name
ARTICLE
Table 5: Substrate scope of quinazoline-2,4(1H,3H)-dione
Sr
substrate
product
%
4. 7-Methylquinazoline-2,4(1H,3H)-dione (Table 5 (4))
1
H NMR (500 MHz, DMSO) δ 11.18 (s, 1H), 11.06 (s, 1H),
no.
conversion
CN
7.74 (dd, J = 7.9, 3.1 Hz, 1H), 7.02 – 6.84 (m, 2H), 2.32 (s,
1
2
3
4
5
6
7
92.3
82.8
86.8
91.5
93.3
75.9
89.2
1
H); C NMR (100 MHz, DMSO-d6) δ 163.15, 150.89,
3
3
NH2
146.06, 141.33, 127.33, 124.11, 115.48, 112.44, 21.86.
5
. 6,7-Dimethoxyquinazoline-2,4(1H,3H)-dione (Table 5
1
5)) H NMR (400 MHz, DMSO-d6) δ =11.09 (s, 1H), 10.94
(
(
s, 1H), 7.21 (s, 1H), 6.62 (s, 1H), 3.89 (s, 3H), 3.65 (s, 3H).
3
C NMR (100 MHz, DMSO-d6) δ = 162.86, 155.31, 150.88,
1
1
45.44, 136.95, 107.52, 106.6, 98.17, 56.17(2C).
6
. 5-Fluoro-1H-quinazoline-2,4(1H,3H)-dione (Table 5 (6))
1
H NMR (400 MHz, DMSO) δ = 10.91(s, 1H), 10.91 (s, 1H),
1
.31 (m, 1H), 6.14 (m, 2H); C NMR (d6-DMSO) δ 166.28,
3
7
1
51.76, 150.38, 142.95, 135.90, 102.9, 100.72, 97.89.
7
. 7-Chloro quinazoline-2,4(1H,3H)-dione (Table 5 (7)
1
H NMR (400 MHz, DMSO) δ = 11.39 (s,1H), 11.24 (s, 1H),
1
3
.86 (d,1H), 7.20 (d, 1H), 7.16 (s, 1H); C NMR (d6-DMSO)
7
δ 162.53, 150.61, 142.39, 139.72, 129.47, 122.93, 115.11,
113.76.
8
. 6-Nitro quinazoline-2,4(1H,3H)-dione (Table 5 (8))
1
H NMR (400 MHz, d6-DMSO) δ = 11.73 (s, 2H), 8.44(d, 1H),
13
8.37(t, 1H), 7.30(d, 1H); C NMR (d6-DMSO) δ 162.13,
1
50.59, 146.10, 142.29, 129.32, 123.55, 116.30, 115.41.
8
84.6
Possible reaction mechanism
The reaction mechanism for the synthesis of quinazolinedione
by condensation of 2ABN with CO
proposed as shown in Figure 13. Chemical interaction of water
and CO forms H CO , this formation and decomposition of
CO through bicarbonate ion as an intermediate.
CO , HCO
scheme. The catalyst used La-Mg MO is basic in nature so
2
using La-Mg MO is
Reaction conditions: 2ABN (5 mmol), CO
2
pressure (3.5 MPa), reaction
2
2
3
temperature (140°C), solvent (30 mL), La-Mg mixed oxide 0.02% (w/v), reaction
time (14 h), (a): isolated yield.
61–63
H
2
3
The
3 2 3
and H CO is in equilibrium by Eigen’s triangular
-
2
NMR data;
there is the possibility of adsorption of H
catalyst.
2 3
CO on the surface of
1
. Quinazoline-2,4(1H,3H)-dione (Table 5 (1))
1
1
H NMR: δ = H NMR (500 MHz, DMSO-D
6
) δ 11.27 (s, 1H),
1
7
1
1
1.12 (s, 1H), 7.86 (d, J = 7.4 Hz, 1H), 7.60 (t, J = 7.3 Hz, 1H),
3
1
6
.15 (t, J = 7.3 Hz, 2H); C NMR (126 MHz, DMSO D ) δ
63.27 (s), 150.74 (s), 141.27 (s), 135.37 (s), 127.37 (s),
22.75 (s), 115.74 (s), 114.74 (s).
2.
5-Chloroquinazoline-2,4(1H,3H)-dione (Table 5 (2))
H NMR (500 MHz, DMSO) δ 11.23 (t, J = 20.7 Hz, 2H), 7.52
dd, J = 11.8, 4.3 Hz, 1H), 7.20 – 7.15 (m, 1H), 7.10 (dd, J =
1
Due to the basicity of catalyst the H CO (mild acid) get
3
2
(
1
3
adsorbed on the basic site of the of catalyst surface and CO
molecule get activated.
2
8.3, 0.9 Hz, 1H); C NMR (126 MHz, DMSO) δ 161.24 (s),
150.07 (s), 143.96 (s), 135.11 (s), 134.24 (s), 125.48 (s),
115.18 (s), 111.59 (s).
Basicity of 2ABN is too low (pKa = 0.77) and also the H CO is
3
2
weak acid, therefore direct attack of H CO on amine group of
2
3
3
. 6-Chloroquinazoline-2,4(1H,3H)-dione (Table 5 (3))
1
2ABN is not feasible. Therefore, the H
2
CO hydrolyses -CN
3
H NMR (500 MHz, DMSO) δ 11.54 (s, 1H), 11.37 (s, 1H),
.89 (dd, J = 6.7, 2.5 Hz, 1H), 7.80 – 7.72 (m, 1H), 7.31 –
group. This reaction shows a similar type of mechanism
pathway as previously reported literature i.e. without catalyst
7
1
3
7.23 (m, 1H); C NMR (126 MHz, DMSO) δ 162.25 (s),
150.47 (s), 140.13 (s), 135.23 (s), 126.72 (s), 126.33 (s),
117.94 (s), 116.19 (s).
3
4,64
synthesis of quinazolinedione in water.
Main difference is
the use of a catalyst to minimizes the activation energy of CO2.
This journal is © The Royal Society of Chemistry 20xx
RSC. Adv., 2016, 00, 1-3 | 7
Please do not adjust margins

Please do not adjust margins
RSC Advances
Page 8 of 13
View Article Online
DOI: 10.1039/C6RA15802A
ARTICLE
Journal Name
Surface reaction of AS and BS on catalyst site, there is
formation of CS,
k
1
Kinetics
A.S + B.S ←→C.S + S
a
b
a
b
(
3)
In the absence of mass transfer and intraparticle diffusion
resistance, the reaction seems to be kinetically controlled. The
reaction was supposed to occur by LHHW with dual site
Rate of desorption of quinazolinedione (C) is given by,
1
K
C
mechanism. To prove this we have developed a mathematical C.S ← → C + S
model to calculate different constants and thus calculated the
a
a
(
(
4)
5)
6
5–68
activation energy for the reaction.
reaction between 2ABN (A) and CO
catalyst surface and A will chemisorb on the S
carbon dioxide) will adsorb on S (basic) catalyst site.
Considering the The overall rate of reaction is as follows;
2
(B) happens on the
(acidic) and B
rate(−r ) = k C
C
− k ' .C .CSb
a
A
1
A.S a B.S b
1
C.Sa
(
b
For general chemical reaction;
Site balance
A + B → C
CASa = K .C .C
A
A
Sa
(
6)
7)
Adsorption of 2ABN (A) and carbon dioxide (B) on catalyst sites
is given by,
C
= K .p .C
B.Sb
B
B
Sb
(
K
a
A+ S ←→A.S
a
a
(
1)
2)
K
B
B + S ←→B.S
b
b
(
8
| RSC. Adv., 2016, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Please do not adjust margins
RSC Advances
Page 9 of 13
View Article Online
DOI: 10.1039/C6RA15802A
RSC Advances
ARTICLE
Figure
13:
Possible
mechanism
for
synthesis
of
quinazolinedione
For basic sites,
CC.Sa = K .C .C
C
C
Sa
(8)
C = C +CSb
t
B.Sa
b
The total concentration of the sites is;
For acidic sites,
C = (K .p .C +C )
t
B
B
S
S
b
b
b
C = C
+ CC.Sa + CSa
t
A.Sa
C = (1+ K .p ).C
a
t
B
B
Sb
(9)
b
C = K .C .C + K .C .C +CSa
t
a
A
A
S
a
C
C
CS
a
Ctb
C =
S
C = (K .C + K .C .+1)C
b
t
a
A
A
C
C
S
a
(1+ K .p )
B
B
(
11)
Cta
1+ K .C + K .C .)
CSa
=
(
A
A
C
C
(10)
This journal is © The Royal Society of Chemistry 2016
RSC Adv., 2016, 00, 1-3 | 9
Please do not adjust margins

Please do not adjust margins
RSC Advances
Page 10 of 13
View Article Online
DOI: 10.1039/C6RA15802A
ARTICLE
Journal Name
−
dCA
'
1
Experimental
rate =
= k K C C .K .p C −k K C C C
1
A
A.
S
a
B
B.
S
b
C
C.
S
a
.
S
b
dt
(
12)
Chemicals
Urea, La(NO
3
)
3
.6H
2
O and Mg(NO
3
)
2
.6H
2
O were supplied by S.
From Equation 10, 11 and 12 we have
dCA k .K .K .C .p .C .C − k K C C C
D. fine chemicals, Mumbai, India. 2ABN (purity >98%) and all
related compounds were supplied by Sigma-Aldrich. All
'
1
−
1
A
B
A
B
t
t
C
C.
t
.
t
chemicals used as such without further purification. CO gas
2
a
b
a
b
−
r =
=
A
i
(Purity 99.99%) purchase from Rakhangi Mumbai.
dt
(1+ K .C + K .C )(1+ K .p )
A
A
C
C
B
B
(
13)
Preparation of La-Mg MO
For initial rate of reaction, we can write above equation as;
0.015 mmol Mg(NO ) .6H O and 0.005 mmol La(NO ) .6H O
3
2
2
3 3
2
(
mole ratio La/Mg = 1:3) were dissolved in 150 mL distilled
water. Then, 0.09 mol urea was added (nitrate to urea ratio
:2) into the above solution, which was agitated at 30°C for 30
k .K .K .C .p .C .C
tb
−
dCA
1
A
B
A
B
t
a
−
r =
=
A
i
1
dt
(1+ K .C )(1+ K .p )
A
A
B
B
min. After that solution was transferred to a teflon lining bomb
reactor and kept at 433°K for 24 h then cool it naturally at
room temperature. Then, the precipitate was filtered and
washed multiple times with distilled water up to neutral pH.
Then it dried at 373°K in the oven for 12 h and further calcined
at 923°K at a ramp rate of 2 °K/min in the presence of air for 4
Consider, k .C .C = k 'w
1
t
t
b
a
−
dCA
dt
k '.w.K .K .C .p
B
A
B
A
−
r =
=
A
i
(1+ K .C )(1+ K .p )
A
A
B
B
(
14)
2 3
h and store in air tight container. Similarly, the La O and MgO
also prepared by using the same method used for La-Mg MO.
By solving this equation with Solver we have calculated rate
constant and adsorption constant for 2-aminibenzonitrile and
carbon dioxide as per given in Table 6 below,
Synthesis of quinazolinedione
2
The reaction of 2ABN and CO was carried out at 140°C in
3
8
autoclave. In this experiment, 5 mmol of 2ABN and 30 mL
water were added to the autoclave and flushed 2-3 times with
Table 6: adsorption constants
CO
40°C and pressurized with CO
CO pressure and the temperature were maintained
2
, to remove unwanted air. Then, the reactor was heated
Temperature Rate constant(k)
Adsorption
constant (K
Adsorption
1
2
at 3.5 MPa. The desired
3
(
°K)
(cm /g-
cat/atm/h)
0.028937
A
)
constant (K
B
)
3
-1
2
(cm /mol)
(atm )
throughout the experiments. The sampling was done
periodically so as for check reaction progress by HPLC
analysis. At end of reaction, the reactor was cooled to room
3
4
4
4
93
03
13
23
1.635
0.0045
0.0042
0.0039
0.0035
0.060757
0.120673
0.239943
1.510
1.420
1.390
2
temperature and then CO release to the atmosphere. The
product was extracted with organic solvents. The product
structure was confirmed by mass and H-NMR.
The activation energy was calculated by Arrhenius equation;
the apparat activation energy is found to be 23.3 kcal/mol
Conclusion
(Figure 14)
0
In summary, we have successfully developed homogeneous
precipitation method (urea method) for preparation of La-Mg
MO. This is an efficient catalyst for synthesis quinazoline-
y = -9143.1x + 20.617
R² = 0.9989
-
-
-
0.5
2
2,4(1H,3H)-dione from the coupling of 2-ABN and CO . For this
-1
reaction water was used as a reaction medium; conventionally
organic solvents have been used in the synthesis of
quinazolinediones. The strong basicity of La-Mg MO is the
1.5
-2
2
reason behind the activation of CO . The catalyst was recycled
for three times without any noticeable loss in its activity. We
have developed cost-efficient and eco-friendly La-Mg MO
which is highly basic water resistant recyclable catalyst.
2.5
-3
0
.00235
0.0024
0.00245
0.0025
0.00255
0.0026
1
/T
Acknowledgements
Figure14: Plot of ln k vs 1/T
G. D. Yadav received support from R. T. Mody distinguished
Professor endowment and as J. C. Bose National Fellow from
Department of Science and Technology, Government of India.
1
0 | RSC. Adv., 2016, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 11 of 13
Journal Name
PleaseRd So Cn oA t da vd aj un s ct ems argins
View Article Online
DOI: 10.1039/C6RA15802A
ARTICLE
K.B. Rasal is greatly thankful to Department of Science and
Technology (DST), India for financial support under ‘Indo- 28
Finnish’ project and ICT (Mumbai) for providing lab facility.
2014, 16, 3142.
W. Lu, J. Ma, J. Hu, J. Song, Z. Zhang, G. Yang and B. Han,
Green Chem., 2014, 16, 221–225.
2
3
3
3
3
3
3
3
9
0
1
2
3
4
5
6
T. Mizuno, M. Mihara, T. Nakai, T. Iwai and T. Ito, Synthesis
(
Stuttg)., 2007, 2007, 2524–2528.
J. Gao, L. N. He, C. X. Miao and S. Chanfreau, Tetrahedron,
010, 66, 4063–4067.
T. Mizuno, T. Iwai and Y. Ishino, Tetrahedron Lett., 2004,
5, 7073–7075.
Y. Xiao, X. Kong, Z. Xu, C. Cao, G. Pang and Y. Shi, RSC Adv.,
015, 5, 5032–5037.
References
2
1
2
3
W. M. To, J. Clean. Prod., 2015, 103, 658–664.
L. Li, N. Zhao, W. Wei and Y. Sun, Fuel, 2013, 108, 112–130.
W. Mcghee, D. Riley, K. Christ, Y. Pan and B. Parnas, J. Org.
Chem., 1995, 60, 2820–2830.
4
2
4
X. Han and M. Poliakoff, Chem. Soc. Rev., 2012, 41, 1428–
Y. P. Patil, P. J. Tambade, S. R. Jagtap and B. M. Bhanage,
Green Chem. Lett. Rev., 2008, 1, 127–132.
36.
5
6
N. Abas and N. Khan, J. CO2 Util., 2014, 8, 39–48.
J. Ma, B. Han, J. Song, J. Hu, W. Lu, D. Yang, Z. Zhang, T.
Jiang and M. Hou, Green Chem., 2013, 15, 1485.
C. Murugan and H. Bajaj, Indian J. Chem., 2013, 52, 459–
H. Wang, Y. Liu, M. Li, H. Huang, H. M. Xu, R. J. Hong and H.
Shen, Optoelectron. Adv. Mater. Rapid Commun., 2010, 4,
1
166–1169.
Q. Liu, L. Wu, R. Jackstell and M. Beller, Nat. Commun.,
015, 6, 5933.
M. Aresta and A. Dibenedetto, Dalton Trans., 2007, 2975–
992.
C. Maeda, Y. Miyazaki and T. Ema, Catal. Sci. Technol.,
014, 4, 1482.
W. Wang, S. Wang, X. Ma and J. Gong, Chem. Soc. Rev.,
011, 40, 3703–3727.
D. J. Darensbourg and M. W. Holtcamp, Coord. Chem. Rev.,
996, 153, 155–174.
4
66.
7
8
9
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
M. L. Kantam, K. B. S. Kumar, V. Balasubramanyam, G. T.
2
Venkanna and F. Figueras, J. Mol. Catal. A Chem., 2010,
3
21, 10–14.
2
3
3
7
8
M. L. Kantam, V. Balasubrahmanyam, K. B. S. Kumar, G. T.
Venkanna and F. Figueras, Adv. Synth. Catal., 2007, 349,
2
1
887–1890.
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
F. S. H. Simanjuntak, V. T. Widyaya, C. S. Kim, B. S. Ahn, Y. J.
Kim and H. Lee, Chem. Eng. Sci., 2013, 94, 265–270.
M. Ogawa and H. Kaiho, Langmuir, 2002, 18, 4240–4242.
H. Willard and N. Tang, J. Am. Chem. Soc., 1937, 1190–
2
3
4
9
0
1
L. Torrente-Murciano, D. Mattia, M. D. Jones and P. K.
Plucinski, J. CO2 Util., 2014, 6, 34–39.
1
196.
M. Zhou, J. Yu and H. Yu, J. Mol. Catal. A Chem., 2009, 313,
07–113.
4
4
4
4
4
4
4
1
2
3
4
5
6
7
A. Goeppert, M. Czaun, J.-P. Jones, G. K. Surya Prakash and
G. a Olah, Chem. Soc. Rev., 2014, 43, 7995–8048.
K. Huang, C.-L. Sun and Z.-J. Shi, Chem. Soc. Rev., 2011, 40,
1
R. Gunawidjaja, H. Diez-y-Riega and H. Eilers, Powder
Technol., 2015, 271, 255–261.
2
435–2452.
M. Usman and W. M. A. W. Daud, RSC Adv., 2015, 5,
1945–21972.
L. Jiarong, C. Xian, S. Daxin, M. Shuling, L. Qing and Z. Qi,
009, 4, 13–16.
V. Štengl, J. Šubrt, P. Bezdička, M. Maříková and S.
Bakardjieva, Solid State Phenom., 2003, 90–91, 121–128.
I. Y. Park, D. Kim, J. Lee, S. H. Lee and K. J. Kim, Mater.
Chem. Phys., 2007, 106, 149–157.
2
2
Happy, a I. Y. Tok, L. T. Su, F. Y. C. Boey and S. H. Ng, J.
Nanosci. Nanotechnol., 2007, 7, 907–915.
Y. P. Patil, P. J. Tambade, K. D. Parghi, R. V. Jayaram and B.
M. Bhanage, Catal. Letters, 2009, 133, 201–208.
T. Kimura, K. Kamata and N. Mizuno, Angew. Chemie - Int.
Ed., 2012, 51, 6700–6703.
X. Li, G. B. Ma and Y. Y. Liu, Ind. Eng. Chem. Res., 2009, 48,
7
63–768.
G. Li, C. Peng, C. Zhang, Z. Xu, M. Shang, D. Yang, X. Kang,
S. Fujita, M. Tanaka and M. Arai, Catal. Sci. Technol., 2014,
W. Wang, C. Li, Z. Cheng and J. Lin, Inorg. Chem., 2010, 49,
4
, 1563.
D. B. Nale, S. Rana, K. Parida and B. M. Bhanage, 2014, 4,
–26.
D. B. Nale, S. D. Saigaonkar and B. M. Bhanage, J. CO2 Util.,
014, 8, 67–73.
Y.-N. Zhao, B. Yu, Z.-Z. Yang and L.-N. He, RSC Adv., 2014, 4,
8941.
D. Nagai and T. Endo, J. Polym. Sci. Part A Polym. Chem.,
009, 47, 653–657.
1
0522–35.
4
4
5
8
9
0
R. K. Marella, K. S. Koppadi, Y. Jyothi, K. S. Rama Rao and D.
R. Burri, New J. Chem., 2013, 37, 3229.
0
Y. Wei, S. Zhang, S. Yin, C. Zhao, S. Luo and C. T. Au, Catal.
Commun., 2011, 12, 1333–1338.
2
a. S. Ivanova, B. L. Moroz, E. M. Moroz, Y. V. Larichev, E. a.
Paukshtis and V. I. Bukhtiyarov, J. Solid State Chem., 2005,
2
1
78, 3265–3274.
2
5
1
a. Desmartin-Chomel, B. Hamad, J. Palomeque, N.
Y. P. Patil, P. J. Tambade, K. M. Deshmukh and B. M.
Bhanage, Catal. Today, 2009, 148, 355–360.
Essayem, G. Bergeret and F. Figueras, Catal. Today, 2010,
1
52, 110–114.
C.-G. Li, L. Xu, P. Wu, H. Wu and M. He, Chem. Commun.,
014, 50, 15764–15767.
X.-D. Lang, S. Zhang, Q.-W. Song and L.-N. He, RSC Adv.,
5
5
2
3
2015, 5, 15668–15673.
2
Y. Zhao, B. Yu, Z. Yang, H. Zhang, L. Hao, X. Gao and Z. Liu,
Angew. Chemie - Int. Ed., 2014, 53, 5922–5925.
G. Mascolo and M. C. Mascolo, Microporous Mesoporous
Mater., 2015, 214, 246–248.
H. Zheng, X. Cao, K. Du, J. Xu and P. Zhang, Green Chem.,
This journal is © The Royal Society of Chemistry 20xx
RSC. Adv., 2016, 00, 1-3 | 11
Please do not adjust margins

Please do not adjust margins
RSC Advances
Page 12 of 13
View Article Online
DOI: 10.1039/C6RA15802A
ARTICLE
Journal Name
5
4
C. Li, M. Wei, D. G. Evans and X. Duan, Catal. Today, 2015,
47, 163–169.
N. Kumar Verma, Adv. Mater., 2015, 4, 11.
B. Yu, J.-N. Xie, C.-L. Zhong, W. Li and L.-N. He, ACS Catal.,
015, 5, 3940–3944.
L. W. Diamond and N. N. Akinfiev, Fluid Phase Equilib.,
003, 208, 265–290.
2
5
5
6
5
2
57
58
59
2
O. Warr, C. a. Rochelle, A. Masters and C. J. Ballentine,
Geochim. Cosmochim. Acta, 2015, 159, 112–125.
M. T. Nguyen, M. H. Matus, V. E. Jackson, V. T. Ngan, J. R.
Rostad and D. a. Dixon, J. Phys. Chem. A, 2008, 112, 10386–
10398.
60
61
62
63
M. Jödecke, Á. Pérez-Salado Kamps and G. Maurer, J.
Chem. Eng. Data, 2012, 57, 1249–1266.
B. Hirshberg and R. B. Gerber, J. Phys. Chem. Lett., 2016, 7,
2
905–2909.
A. Stirling and I. Pápai, J. Phys. Chem. B, 2010, 114, 16854–
6859.
1
D. Pines, J. Ditkovich, T. Mukra, Y. Miller, P. M. Kiefer, S.
Daschakraborty, J. T. Hynes and E. Pines, J. Phys. Chem. B,
2016, 120, 2440–2451.
64
65
66
67
68
J. Ma, J. Hu, W. Lu, Z. Zhang and B. Han, Phys. Chem. Chem.
Phys., 2013, 15, 17333–41.
M. S. Tiwari, G. D. Yadav and F. T. T. Ng, Can. J. Chem. Eng.,
2
014, 92, 2157–2165.
G. D. Yadav and R. K. Mewada, Chem. Eng. J., 2013, 221,
00–511.
Y. G. and G. P., Clean Technol. Environ. Policy, 2003, 4, 227–
34.
G. D. Yadav and N. S. Doshi, Green Chem., 2002, 4, 528–
40.
5
2
5
1
2 | RSC. Adv., 2016, 00, 1-3
This journal is © The Royal Society of Chemistry 20xx
Please do not adjust margins

Page 13 of 13
RSC Advances
View Article Online
DOI: 10.1039/C6RA15802A
La-Mg mixed oxide as highly basic water resistant catalyst for utilization of
CO
2
in synthesis of quinazoline-2,4(1H,3H)-dione
Kalidas B. Rasal, Ganapati D. Yadav*
*Department of Chemical Engineering, Institute of Chemical Technology (ICT), Nathalal Parekh
Marg, Matunga (E), Mumbai - 400 019, INDIA.
Synthesis of Quinazoline-2,4(1H,3H)-dione using La-Mg mixed oxide in water