Hydrochloric Acid → HCID 15575766, compound

Participants

Reaction Steps

4-(2-tert.-Butoxycarbonylamino-ethyl)-thiosemicarbazide (9.37 g) is added to a solution of sodium (0.92 g) in methanol (40 cc) at 20° C., and diethyl oxalate (5.4 g) is then introduced dropwise in the course of 10 minutes. The mixture is heated under reflux for 3 hours. It is allowed to cool, water (100 cc) is added, concentrated hydrochloric acid (3 cc) is introduced dropwise, the mixture is extracted with ethyl acetate (2×100 cc) and the extract is washed with a saturated sodium chloride solution (2×50 cc), dried over sodium sulphate, filtered and concentrated to dryness at 20° C. under 20 mm Hg (2.7 kPa). The residue is taken up in methylene chloride (65 cc), the crystallisation is started, the batch is left for 2 hours at 20° C. and then filtered, and white crystals (4.59 g) of 4-(2-tert.-butoxycarbonylamino-ethyl)-5,6-dioxo-3-thioxo-perhydro-1,2,4-triazine, melting at 160° C., are obtained.

Provenance & Evidence