Table 1.
Effect of amounts of H3PW12O40 and other catalysts on the synthesis of 3a by the reaction of 2-aminobenzophenone (1), and ethyl acetoacetate (2).
| Entrya | Catalyst (mol%) | Yield (%)b | Time (h) |
|---|---|---|---|
| 1 | H3PW12O40 (0.1) | 30 | 24 |
| 2 | H3PW12O40 (0.2) | 45 | 20 |
| 3 | H3PW12O40 (0.3) | 50 | 12 |
| 4 | H3PW12O40 (0.4) | 50 | 8 |
| 5 | H3PW12O40 (0.5) | 50 | 6 |
| 6 | H3PW12O40 (0.6) | 55 | 5 |
| 7 | H3PW12O40 (0.7) | 60 | 3.5 |
| 8 | H3PW12O40 (0.8) | 75 | 3 |
| 9 | H3PW12O40 (0.9) | 83 | 2.5 |
| 10 | H3PW12O40 (1) | 90 | 2 |
| 11 | H3PW12O40 (1.1) | 91 | 2 |
| 12 | H3PW12O40 (1.2) | 91 | 2 |
| 13 | HClO4 (1) | 40 | 12 |
| 14 | H2SO4 (1) | 30 | 12 |
| 15 | SSA (1) | 60 | 5 |
| 16 | ZnCl2 (1) | 40 | 12 |
| 17 | TsOH (1) | 50 | 12 |
a In all reaction the conditions were optimized for a 100% conversion; b Isolated yield.