Synthesis of 14-Aryl-14H-dibenzo[a,j]xanthene Derivatives Using H-Zeolite A as an Efficient and Reusable Catalyst under Solvent-Free Condition

Table 4

Comparison of H-Zeolite A for the synthesis of 14-(4-chlorophenyl)-14H-dibenzo[a,j]xanthene.

Entry	Catalyst	Condition	Time (h)	Yield (%)	Ref.
1	H2SO4	AcoH/80°C	73	60	[24]
2	Silica H2SO4	S.f./80°C	15–120 min	80–96	[28]
3	Amberlyst-15	S.f./125°C	0.5–2	80–94	[30]
4	Yb(OTf)3	(13py) Bf4	5–7	80–95	[36]
5	NaHSO4	S.f./90°C	0.5–1	74–91	[32]
6	Cellulose H2SO4	S.f./110°C	1.5–3	81–97	[37]
7	H-Zeolite A	S.f./100°C	15–35 min	94–98	This work

S.f.: solvent free.