T 1441 (OTTO) p-Toluenesulfonyl isocyanate, 96% Cas 4083-64-1 - used to prepare acetylated syn-1,2-diols,oxazolidin-2-ones, 2,3-diamino acids, and N-tosylcarbonamides. -Toluenesulfonyl isocyanate has been used as derivatization reagent in determination of 3-α-hydroxy tibolone in human plasma by LC-MS/MS.