DABCO Catalyzed Synthesis of Xanthene Derivatives in Aqueous Media

Table 1

Influence of the amounts of DABCO on the synthesis of 1d at reflux temperature^a.

Entry	Catalyst	Amount of catalyst	Time (min)	Yield^b (%)
		(mmol%)
1	None	—	80	Trace
2	DABCO	1	70	67
3	DABCO	2	60	74
4	DABCO	3	50	82
5	DABCO	5	40	89
6	DABCO	10	30	96
7	DABCO	15	30	96

^aReaction conditions: 3-methyl thienaldehyde (1 mmol), dimedone (2 mmol) in water (20 mL) under reflux temperature. ^bIsolated yields.