Table 1.
Entry a | Reaction time / h | KOH concentration / % (w/w) | The amount of Bu4NBr / mol % | Reaction temperature / °C | Yield b / % |
1 | 1 | 30 | 3 | 88-90 | 38.8 |
2 | 1 | 30 | 5 | 88-90 | 62.2 |
3 | 1 | 30 | 8 | 88-90 | 77.1 |
4 | 1 | 30 | 10 | 88-90 | 77.4 |
5 | 1 | 30 | 0 | 88-90 | 8.5 |
6 | 1 | 10 | 8 | 88-90 | 48.5 |
7 | 1 | 20 | 8 | 88-90 | 69.1 |
8 | 1 | 35 | 8 | 88-90 | 83.0 |
9 | 1 | 40 | 8 | 88-90 | 74.0 |
10 | 1 | 35 | 8 | 20-25 | 4.3 |
11 | 1 | 35 | 8 | 40-45 | 13.3 |
12 | 1 | 35 | 8 | 60-65 | 65.0 |
13 | 2 | 35 | 8 | 88-90 | 83.8 |
14 | 0.75 | 35 | 8 | 88-90 | 74.5 |
15 | 0. 5 | 35 | 8 | 88-90 | 55.9 |
a Reaction conditions: A mixture of quinazolin-4-one (1 equiv) (2e), 1-bromopropane (1 equiv), Bu4NBr (0.03-0.1 equiv), 10-40 % potassium hydroxide (10 mL) in toluene (10 mL) was stirred at 20-90°C for 0.5-2 h. b Yields of isolated products.