Al(NO3)3 · 9H2O: An Efficient Catalyst for the One-Pot Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones Both under Reflux or Solvent-Free Conditions
Table 4
Synthesis of various dihydropyrimidinones catalyzed by Al (NO3)3·9H2O in refluxing ethanol (I) and solvent-free conditions at 80°C .
Entry
R
R1
X
Time (h:min)
Yield (%)
I
II
I
II
1
Ph
OEt
O
7:00
00:30
92
97
2
Ph
OMe
O
7:00
00:20
93
95
3
Ph
OEt
S
8:00
00:60
80
85
4
4-Cl-C6H4
OEt
O
7:00
1:30
85
88
5
4-Cl-C6H4
OMe
O
7:00
1:30
80
90
6
2-Cl-C6H4
OEt
O
7:00
00:30
70
95
7
2-Cl-C6H4
OMe
O
7:00
00:30
80
97
8
4-CH3-C6H4
OEt
S
6:00
2:00
90
95
9
2-MeO-C6H4
OEt
O
6:00
2:00
99
99
10
4-MeO-C6H4
OEt
O
7:00
3:00
88
92
11
3,4-DiMeO-C6H4
OMe
O
7:00
3:00
70
92
12
3-Br-C6H4
OEt
O
8:00
3:00
80
87
13
4-F-C6H4
OEt
O
9:00
2:30
85
99
14
2-Furyl
OMe
O
8:00
2:00
85
88
15
3-EtO-4-HO-C6H4
OEt
O
9:00
1:30
82
88
16
4-Me2N-C6H4
OEt
O
8:00
3:00
80
92
17
3-O2N-C6H4
OEt
O
9:00
3:00
70
90
Yields refer to isolated products which were characterized by comparison of their spectroscopic and physical data with those of samples synthesized by reported procedures.
