Table 1. Optimization of the One-Pot Gewald Reaction.

entry	base (equiv)	solvent	temp (°C)	time (h)	yield of 3a (%)
1	imidazole (0.1)	DMF	60	18	10
2	imidazole (0.1)	DMF	80	24	14
3	imidazole (0.25)	DMF	60	24	18
4	imidazole (0.25)	2-Me-THF	60	24	32
5	imidazole (0.5)	2-Me-THF	60	24	36
6	imidazole (1.0)	2-Me-THF	60	24	40
7	imidazole (1.0)	2-Me-THF	80	24	40
8	imidazole (1.0)	dioxane	60	24	35
9	morpholine (1.0)	2-Me-THF	60	24	<1
10	piperidine (1.0)	2-Me-THF	60	24	<1
11	morpholine (1.0)	DMF	60	24	<1
12	piperidine (1.0)	DMF	60	24	<1
13	proline (0.1)	DMF	60	24	26
14	proline (0.25)	DMF	60	24	26
15	imidazole (1.0)	2-Me-THF	60	24	57a

^aAddition of sulfur 1.5 h after the reaction of acetophenone with malononitrile.