2-Fluoroaniline → 4-Bromo-2-fluoroaniline

Participants

Reaction Steps

Cycle 1. Methylene chloride, 125 ml, and 32.2 g (0.1 mol) tetrabutylammonium bromide were mixed in a 200-ml, 3-necked roundbottom flask, equipped with a mechanical stirrer, a thermometer, an additional funnel and a water condenser leading to a mineral oil bubbler. Bromine, 16.0 g (0.1 mol), was added to the mixture over 15 minutes at room temperature. The temperature of the mixture rose from 24° C. to 30° C. The contents of the flask were stirred for 30 minutes. 2-fluoroaniline, 11.1 g (0.1 mol), at room temperature, was added to the mixture in one portion. The temperature of the mixture rose to 40° C. The orange solution immediately turned yellowish. After stirring for 15 minutes, the solution turned milky and the temperature was 32° C. After 30 more minutes, solids were observed. The solution was filtered and the solids washed with ice-cold methylene chloride until white. On air-drying 9 g of product (Solid I) was obtained. The melting point was >200° C. LC analysis showed only desired product with a trace of impurity. LC analysis of the mother liquor (I) showed that it contained some desired product and some dibrominated compound.

Provenance & Evidence