p-Tolyl isothiocyanate has been used in the preparation of 6-[1-amino-3-(p-tolyl)-thiourea]-2-ethylbenzo[de]isoquinoline-1,3-dione. It is used as capping agent to cap the N-terminal ends of polypeptide. It is also used as pharmaceutical intermediate.
p-Tolyl isothiocyanate reacts with 6-hydroxy-2,4,5-triaminopyrimidine or with 4,5,6-triaminopyrimidine in DMF and triethylamine to yield 2,4-diamino-5-(p-tolylthioureido)aminopyrimidin-6-one and 4,6-diamino-5-(tolylthioureido)aminopyrimidine, respectively.