Research Article

p-Sulfonic Acid Calix[4]arene as an Efficient Catalyst for One-Pot Synthesis of Pharmaceutically Significant Coumarin Derivatives under Solvent-Free Condition

Table 1

Coumarins prepared from tetrasulfonic acid calixarene via Pechmann reaction.

SubstrateProductTime (h)Yield (%) M. P. (found) M. P. (obtained)

11a241579–81 [46]78-79
22a2.595182–184 [47]183–185
33a475241-242 [46]240–242
44a2.550130-131 [48]132
85a290158–160 [47]158-159
66a2.584220–224 [49]222–224
77a2.588234-235 [47] 232–234
88a1.595173–175
99a492153–155 [47]151–154
1010a1030182-183 [50]180-181
1111a24

M. P.: melting point.