2-Amino-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3-carbonitrile, N6-BOC protectedtert-butyl 2-amino-3-cyano-4,7-dihydrothieno[2,3-c]pyridine-6(5H)-carboxylatetert-Butyl 2-amino-3-cyano-4,7-dihydrothieno[2,3-c]pyridine-6(5H)-carboxylatetert-Butyl 2-amino-3-cyano-4,7-dihydrothieno-[2,3-c]pyridine-6(5H)-carboxylate