128366-08-5 2-Mercapto-5,6-dihydro-7H-pyrrole(1,2-a)imidazole 5H-Pyrrolo(1,2-a)imidazole-2-thiol, 6,7-dihydro- 6,7-Dihydro-5H-pyrrolo(1,2-a)imidazole-2-thiol