Hydrochloric Acid → 1-Amino-2-methylindoline hydrochloride

Participants

Reaction Conditions

Reaction Steps

140 g of 2-methylindoline was dissolved in 750 ml of acetonitrile. 110 ml of concentrated hydrochloric acid was added and the solution was cooled. A solution of 75 g of sodium nitrite in 300 ml of water was added dropwise. The pH of the solution was adjusted to about 7 with ammonium acetate followed by portionwise addition of 160 g of zinc dust and 385 g of ammonium acetate. Next, 100 ml of water was added and the mixture was stirred for about 2 hours at 45° C. The solids were filtered off and washed with toluene (3×250 ml). The tolune washes were then used to extract the filtrate. The toluen washes were then combined, acidified with 120 ml of concentrated hydrochloric acid and 120 g of ice was added to obtain the crystals of the title compound. The crystals were separated by filtration, washed with toluene and dried. The dried material was checked by TLC and was of good quality.

Provenance & Evidence