Sulfuric Acid → 2-Amino-2,3-dimethylbutanamide

Participants

Reaction Conditions

Reaction Steps

To concentrated sulfuric acid (29.7 ml), cooled with stirring in an ice-acetone cooling bath, is added 11.8 g (-)-2-amino-2,3-dimethylbutyronitrile with [α]D25 =7.31° (c=0.0368 g/ml THF) at such a rate that the temperature does not go above 25° C. After the addition, the temperature of the reaction mixture is slowly raised to 100° C. and held at that temperature for one hour. After cooling the mixture in an ice-acetone bath, 85 ml concentrated ammonium hydroxide is added at such a rate that the temperature does not exceed 75° C. The mixture is extracted five times with methylene chloride, the combined extracts dried and concentrated. This gives 11.95 g of white solid, mp 79°-81° C. and [α]D25 =+57.43° (c=0.0213 g/ml THF). This solid is recrystallized from methylene chloride-hexane to give 11.2 g of (+)-2-amino-2,3-dimethylbutyramide, mp 81°-82° C. [ α]D25 =+59.38° (c=0.0162 g/ml THF).

Provenance & Evidence