Methylation of phloroglucinol was performed using dimethyl sulfate as the methylating agent in the presence and absence of a glycoluril clip. The results showed that the yield of the di-methylated product decreased significantly in the presence of a glycoluril clip (host), due to the formation of a host–guest complex between the clip and phloroglucinol. Also, the reaction was conducted with different quantities (mol %) of the host