反应详情

1,2-Ethanediamine (1.6 mL) was added under nitrogen to a solution of 5-[bis(methylthio)methylene]-2,2-dimethyl-1,3-dioxane-4,6-dione (6 g, 24 mmole, described in example 3) in dry methanol (45 mL). The mixture was stirred at 20°-22° C. for 18 hr. The resultant precipitate was collected and dissolved in 5% methanol in chloroform (v/v). The solution was filtered through silica gel. The filtrate was concentrated under reduced pressure. The residue was crystallized from methanol-diethyl ether to give 4.4 g of the title compound; mp 181°-182° C.; NMR (CDCl3) δ 1.65 (s, 6H), 3.8 (s, 4H), 8.25 (m, 2H); IR (CHCl3) 3350, 1690, 1660, 1645, 1590 cm-1 ; UVλmax (MeOH) 243 nm (ε 25,500).

1. customThe resultant precipitate was collected
2. dissolutiondissolved in 5% methanol in chloroform (v/v)
3. filtrationThe solution was filtered through silica gel
4. concentrationThe filtrate was concentrated under reduced pressure
5. customThe residue was crystallized from methanol-diethyl ether