T 1297 (OTTO) Tetrabutylammonium hydrogensulphate, for HPLC 99%+ Cas 32503-27-8 - used as surface active agent, phase transfer. T 1297 (OTTO) Tetrabutylammonium hydrogensulphate, for HPLC 99%+ Cas 32503-27-8 - may be employed as a catalyst for the green synthesis of glycosyl 1,4-dihydropyridines.