An Efficient One-Pot Multi-Component Synthesis of 3,4-Dihydropyrimidin-2-(1H)-Ones/Thiones Catalyzed by Bismuth (III) Sulfate Trihydrate under Solvent-Free Conditions

Table 2

Bismuth (III) sulfate trihydrate catalyzed synthesis of 3,4-dihydropyrimidinones/thiones derivatives.

Entry	Compound	Substitution	X	M.p. (°C)	Yield (%)
1	5a	H	O	203-204	89
2	5b	4-Methoxy	O	202-203	92
3	5c	4-Nitro	O	212–214	95
4	5d	4-Chloro	O	215-216	93
5	5e	3-Chloro	O	192-193	93
6	5f	4-Fluro	O	182–184	90
7	5g	H	S	208–210	88
8	5h	3-Nitro	S	206–208	86
9	5i	4-Methoxy	S	156–158	86
10	5j	2-Chloro	S	218–220	80
11	5k	2-Nitro	S	190–192	81
12	5m	3-Methoxy	S	160–162	85

Reaction conditions: 2 mmol aldehyde, 2.5 mmol ethyl acetoacetate, 2.5 mmol urea/thiourea, and Bismuth (III) sulfate trihydrate (10 mol%) were refluxed with stirring for 60 min.