e of example 1 were modified as follows a mixture of 0 43 g 0 0019 mole of the dioxime and 3 ml of concentrated sulfuric acid was heated at 60 u00b0 to 80 u00b0 c for 1 5 hours thereafter the reaction mixture was added dropwise to 10 ml of a 5 by weight aqueous solution of stannous chloride then 5 ml of concentrated hydrochloric acid was added and the mixture was heated at 75 u00b0 to 80 u00b0 c for 2 hours whereupon crystals precipitated out after cooling and solid liquid separation the solid was washed with concentrated hydrochloric acid and then with acetone and dried to give 0 22 g 0 0010 mole of crystals the yield was 53 on the dioxime basis based on the results of ir analysis these crystals could be identified as 4 6 diaminoresorcinol dihydrochloride the steps d and e of example 1 were modified as follows a mixture of 2 95 g of polyphosphoric acid 19 29 g of acetic anhydride and lo olg of the dioxime was heated at 90 u00b0 to 100 u00b0 c for about 3 hours after cooling to the reaction mixture were added 1 56 g of stannous chloride 25 g of water and 32 g of.