Furosemide Impurity1盐酸盐(Furfurylamine HCl)

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Furfurylamine hydrochloride (33.46 grams, 0.250 moles) and ammonium thiocyanate (38.14 grams, 0.501 moles) in 71 ml bromobenzene were heated under nitrogen at reflux temperature for 20 minutes and then cooled to room temperature. The reaction mixture was mixed with a solution of 125 ml water and 100 ml ethyl acetate and left at room temperature overnight. The mixture was then diluted to give 500 ml ethyl acetate and 350 ml water and the aqueous layer separated. The organic layer was washed with water and dried over sodium sulfate. After filtration, the organic layer was evaporated to dryness and bromobenzene removed under vacuum. The resulting solids were ground in a mortar and pestle and the fine particles stirred in diethyl ether to remove residual bromobenzene. The solids were then filtered, washed with diethyl ether and vacuum dried over phosphorus pentoxide, yielding 12.06 grams (30%) of N-furfurylthiourea, m.p. 80°-91° C. Recrystallization from benzene gave yellow needles, m.p. 98°-100° C. at reflux temperature for 20 minutes The mixture was then diluted the aqueous layer separated The organic layer was washed with water dried over sodium sulfate After filtration the organic layer was evaporated to dryness and bromobenzene removed under vacuum to remove residual bromobenzene The solids were then filtered washed with diethyl ether and vacuum dried over phosphorus pentoxide

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Starting from 2.03 g (0.01 mol) of 5-acetylamino-2-tetralone and 4.0 g (0.03 mol) of furfurylaminehydrochloride the title compound is obtained analogously to Example 4.1.11 in a yield of 2.1 g (65.4% of theory) and with a melting point of 296° C., which does not change after recrystallisation from methanol/ether.