Sodium silicate from rice husk ash (RHA) was functionalized with 3-(chloropropyl)triethoxysilane (CPTES) to give RHACCl. The chlorine in RHACCl was easily substituted with 1-butylimidazole (BIm) and 7-amino-naphthalene sulphonic acid (ANSA) to form Это и многое другое вы найдете в книге Synthesis of heterogeneous catalysts for acetalization reaction