Preparation of 1,2,3-Naphthalenetriamine, 1,2,5,6- and 1,2,7,8-Naphthalenetetramine, and 5,6,7,8-Quinolinetetramine and -Isoquinolinetetramine by Reduction of the Fused 1,2,5-Thiadiazole Ring

Article abstract of DOI:10.1246/bcsj.65.2221

The two fused 1,2,5-thiadiazole-rings of naphthalenes 1a and 1b, quinoline 2a, and isoquinoline 2b were reduced with tin and concentrated hydrochloric acid in refluxing dioxane, giving the expected 1,2,5,6-anphthalenetetramine (4a) and 1,2,7,8-tetramine derivative 4b, 5,6,7,8-quinolinetetramine (15a) and isoquinoline analogue 15b in moderate yields.Partially reduced diamine 5 was formed as a by-product in the reduction of 1a.The expected 1,2,3,4-naphthalenetetramine (4c) was not obtained in the reduction of 1c at room temperature and the 1,2,3-triamine 8 was formed in 27percent yield.The intermediary formation of 4c was confirmed by acetylating the crude reduction mixture of 1c, giving tetraacetyl derivative 11.The reduction of naphthotris<1,2,5>thiadiazole 3 afforded 4,5-diamine 16 in 44percent yield.Polyamines 4a-b, 8, 15a-b, and 16, were obtained as their hydrochloride(s).