Research Article

Synthesis of 3,4-Dihydropyrimidin-2(1H)-Ones and Their Corresponding 2(1H)Thiones Using Trichloroacetic Acid as a Catalyst under Solvent-Free Conditions

Table 1

Trichloroacetic acid catalyzed one-pot synthesis of 3,4-dihydropyrimidin-2-(1H)-ones or thiones under solvent-free conditions.

EntryR1R2XTime (min)Yield (%)mp (°C, obsd)mp (°C, lit) (ref.)

1C6H5OEtO485201–203202–205 [1]
24-ClC6H4OEtO992212–216210–212 [1]
34-HOC6H4OEtO4090226–228231–233 [2]
43-O2NC6H4OEtO2093225–228227-228 [1]
54-O2NC6H4OEtO585206–209207–209 [1]
6C6H5CH=CHOEtO390225–227223–226 [1]
74-MeOC6H4OEtO2095200–202202–204 [1]
82,4-(Cl)2C6H3OEtO491247–249246–248 [3]
94-MeC6H4OEtO590213–215214–216 [1]
102-MeOC6H4OEtO294262-263260 [4]
112,6-(Cl)2C6H3OEtO396226–228226 [5]
122-ClC6H4OEtO985221–223221–223 [2]
134-BrC6H4OEtO1190212–214215 [6]
14CH3OEtO392188–190194-195 [7]
15CH3CH2CHOEtO5088163–165164–166 [7]
163-MeC6H4OEtO893219–222224–226 [2]
172-FurylOEtO1986202–205202–204 [5]
18C6H5OMeO594208–211210–213 [1]
194-MeOC6H4OMeO985192–195193–196 [3]
204-ClC6H4OMeO892204–206203–205 [1]
214-O2NC6H4OMeO395235–237235-236 [5]
222-ClC6H4OMeO684180–182181–183 [1]
233-O2NC6H4OMeO1290271–274273–275 [2]
244-MeC6H4OMeO1493206–209210–213 [3]
254-HOC6H4OMeO787235–237231–233 [2]
262-MeOC6H4OMeO295284–286285–287 [2]
273-MeC6H4OMeO496214–217216–218 [2]
283-ClC6H4OMeO992208–211209-210 [2]
292,4-(Cl)2C6H3OMeO394252–255252-253 [3]
302-FurylOMeO1188216–218214–216 [8]
31C6H5OEtS2590210–212210–212 [1]
324-ClC6H4OEtS1886181–183184-185 [3]
334-MeOC6H4OEtS2085136–138137–139 [3]
343-O2NC6H4OEtS1587205–208205-206 [8]
35C6H5OMeS1392220–222221-222 [3]