Hydrochloric Acid → Ranisen

Participants

Reaction Steps

To a solution of N-[2-[[5-(1,3-dioxolan-2-yl)-2-furanylmethyl]thio]ethyl]-N'-methyl-2-nitro-1,1-ethenediamine (2.21 g) and dimethylamine hydrochloride (20 g) in water (5 ml) was added 2 N hydrochloric acid (5 ml). After 10 min, dimethylamine (33% in ethanol) (2 ml) was added, the solution cooled to 18° and sodium borohydride (1 g) added portionwise. The suspension was acidified with acetic acid (2.5 ml) and after 15 mins was heated at 60° for 15 mins. The suspension was evaporated to low bulk and an excess of anhydrous sodium carbonate and tetrahydrofuran (100 ml) added. The suspension was refluxed for 2 hours and after 2 hours at room temperature was filtered and the filtrate evaporated in vacuo. The oily residue was chromatographed (silica/methanol) and the appropriate eluate evaporated in vacuo to give the title compound (0.45 g) which was crystallised from methyl isobutyl ketone, m.p. 64°-67° .

Provenance & Evidence