Hydrochloric Acid → 1-Amino-2-methylindoline hydrochloride

Participants

Reaction Conditions

Reaction Steps

135.9 g of 2-methylindoline was dissolved in 750 ml of methanol and 100 ml of concentrated hydrochloric acid was added. The solution was cooled to 15° C. and a 33% solution of sodium nitrite in water was added slowly until the presence of excess nitrite was observed. This reaction mixture was stirred for 30 minutes followed by the addition of 100 g of ammonium acetate. The reaction mixture was cooled to 25°-30° C. and 160 g of zinc dust was added over a period of 20 minutes. Then 670 g of ammonium acetate was added in small portions over a period of 40 minutes. The mixture was stirred for about 60 minutes and then extracted four times with a total of 1 liter of toluene. To the combined toluene extract was added 100 ml of concentrated hydrochloric acid and 80 g of ice. The mixture was cooled and filtered to obtain a solid product. The solid product was washed with toluene and then with acetone and dried. The dried product melted at 272°-4° C. and showed one spot at Rf 0.58 on the Analtech Silica Gel plate, mobile phase hexane/ethylacetate/acetic acid - 7/3/1.

Provenance & Evidence