International Scholarly Research Notices / 2012 / Article / Tab 1 / 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.
Entry R1 R2 X Time (min) Yield (%) mp (°C, obsd) mp (°C, lit) (ref.) 1 C6 H5 OEt O 4 85 201–203 202–205 [1 ] 2 4-ClC6 H4 OEt O 9 92 212–216 210–212 [1 ] 3 4-HOC6 H4 OEt O 40 90 226–228 231–233 [2 ] 4 3-O2 NC6 H4 OEt O 20 93 225–228 227-228 [1 ] 5 4-O2 NC6 H4 OEt O 5 85 206–209 207–209 [1 ] 6 C6 H5 CH=CH OEt O 3 90 225–227 223–226 [1 ] 7 4-MeOC6 H4 OEt O 20 95 200–202 202–204 [1 ] 8 2,4-(Cl)2 C6 H3 OEt O 4 91 247–249 246–248 [3 ] 9 4-MeC6 H4 OEt O 5 90 213–215 214–216 [1 ] 10 2-MeOC6 H4 OEt O 2 94 262-263 260 [4 ] 11 2,6-(Cl)2 C6 H3 OEt O 3 96 226–228 226 [5 ] 12 2-ClC6 H4 OEt O 9 85 221–223 221–223 [2 ] 13 4-BrC6 H4 OEt O 11 90 212–214 215 [6 ] 14 CH3 OEt O 3 92 188–190 194-195 [7 ] 15 CH3 CH2 CH OEt O 50 88 163–165 164–166 [7 ] 16 3-MeC6 H4 OEt O 8 93 219–222 224–226 [2 ] 17 2-Furyl OEt O 19 86 202–205 202–204 [5 ] 18 C6 H5 OMe O 5 94 208–211 210–213 [1 ] 19 4-MeOC6 H4 OMe O 9 85 192–195 193–196 [3 ] 20 4-ClC6 H4 OMe O 8 92 204–206 203–205 [1 ] 21 4-O2 NC6 H4 OMe O 3 95 235–237 235-236 [5 ] 22 2-ClC6 H4 OMe O 6 84 180–182 181–183 [1 ] 23 3-O2 NC6 H4 OMe O 12 90 271–274 273–275 [2 ] 24 4-MeC6 H4 OMe O 14 93 206–209 210–213 [3 ] 25 4-HOC6 H4 OMe O 7 87 235–237 231–233 [2 ] 26 2-MeOC6 H4 OMe O 2 95 284–286 285–287 [2 ] 27 3-MeC6 H4 OMe O 4 96 214–217 216–218 [2 ] 28 3-ClC6 H4 OMe O 9 92 208–211 209-210 [2 ] 29 2,4-(Cl)2 C6 H3 OMe O 3 94 252–255 252-253 [3 ] 30 2-Furyl OMe O 11 88 216–218 214–216 [8 ] 31 C6 H5 OEt S 25 90 210–212 210–212 [1 ] 32 4-ClC6 H4 OEt S 18 86 181–183 184-185 [3 ] 33 4-MeOC6 H4 OEt S 20 85 136–138 137–139 [3 ] 34 3-O2 NC6 H4 OEt S 15 87 205–208 205-206 [8 ] 35 C6 H5 OMe S 13 92 220–222 221-222 [3 ]