Modifikasi reaksi Reimer-Tiemann dengan Katalis transfer fasa Tetrabutil Amonium Perklorat, Tetrametil Amonium Iodida dan 18-Crown Ether-6: studi semi sintesis Vanili dari Pirokatekol = Modification od Reimer-Tienann reaction with phase transfer catalysts: tetrabutyl ammnium perchlorate, tetramethyl ammonium iodidate and 18-crown ether-6: study of semi synthesis vanilin from pyrocathecol