134749-18-1 2-(6,7-Dimethoxy-4-quinazolinyl)hydrazinecarboxamide monohydrochloride dihydrate 6,7-Dimethoxy-4-semicarbazidoquinazoline hydrochloride dihydrate Hydrazinecarboxamide, 2-(6,7-dimethoxy-4-quinazolinyl)-, monohydrochloride, dihydrate