D 2520 (OTTO) Dibenzyl diisopropylphosphoramidite, 95% Cas 108549-23-1 - used for the preparation of phosphopeptides. D 2520 (OTTO) Dibenzyl diisopropylphosphoramidite, 95% Cas 108549-23-1 - used for the synthesis of a GDP (guanosine diphosphate) analog, SML-8-73-1. It is useful for nucleotide coupling.