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

EntryCatalystConditionTime (h)Yield (%)Ref.

1H2SO4AcoH/80°C7360[24]
2Silica H2SO4S.f./80°C15–120 min80–96[28]
3Amberlyst-15S.f./125°C0.5–280–94[30]
4Yb(OTf)3(13py) Bf45–780–95[36]
5NaHSO4S.f./90°C0.5–174–91[32]
6Cellulose H2SO4S.f./110°C1.5–381–97[37]
7H-Zeolite AS.f./100°C15–35 min94–98This work

S.f.: solvent free.