Tert-butyl 2,4-dichloro-8,9-dihydro-5H-pyrimido[4,5-d]azepine-7(6H)-carboxylate; tert-butyl 2,4-dichloro-5,6,8,9-tetrahydro-7H-pyrimido[4,5-d]azepine-7-carboxylate;