GB801169A - Process for the preparation of 2 (alpha-aminoethyl)-furan and derivatives thereof - Google Patents

Abstract

2-(a -aminoethyl)-furan is prepared by reacting 2-acetylfuran with ammonium hydroxide and hydrogen in an aqueous (including aqueous/alcoholic) system in the presence of an hydrogenation catalyst, preferably an activated form of nickel, such as sponge nickel or Raney nickel, although any catalyst which will promote selective reductive amination of the carbonyl group, without leading to reduction of the furan ring may be used. The 2-(a -aminoethyl)-furan may be recovered as such or converted in situ to a salt, e.g. hydrochloride or a 2-(a -acylamidoethyl)-furan, e.g. 2-(a -acetamidoethyl)-furan. The ammonia may be introduced as liquid ammonia, but preferably as ammonium hydroxide, which under optimum conditions represents an ammonia concentration of ca. 10-30 per cent by weight of the water present in the system. The ratio of ammonia to ketone may be as low as 1 : 1, but is preferably at least 4 : 1. The hydrogen is also preferably present in excess. The reaction may be conducted at room temperature, but preferably at about 50-75 DEG C., optionally about 60-65 DEG C. and at an hydrogen pressure as low as about 1 atmos., but preferably about 20-60 p.s.i.g. It is preferred to include a solvent, miscible with both 2-acetylfuran and the product, e.g. a lower alkanol such as isopropanol. In examples: (1) 2-(a -aminoethyl)-furan is prepared by reacting 2-acetylfuran, ammonium hydroxide and hydrogen, in the presence of a Raney nickel catalyst and isopropanol; (2) 2-(a -aminoethyl)-furan is prepared similarly and converted to the acetate by means of glacial acetic acid; (3) this acetate is acetylated with acetic anhydride in pyridine solution to give 2-(a -acetamidoethyl)-furan; (4) 2-(a -aminoethyl)-furan together with some, presumably, N,N - bis - (a - furylethyl) - amine is prepared as in (1), but using a sponge nickel catalyst; (5) the crude 2-(a -aminoethyl)-furan from (4) is converted to the hydrochloride with HCl; the sulphate and phosphate are also mentioned.