Formaldehyde → 1-(5-Bromo-4-nitro-2-thienyl)ethan-1-one

Participants

Reaction Steps

2-Bromo-5-acetyl thiophene oxime (35.2 g) (0.16 mole) was dissolved in concentrated sulphuric acid (80 ml) at 5°-10° C. A mixture of fuming nitric acid (95-98%) (10.6 g) (0.16 mole) in concentrated sulphuric acid (10 ml) was added dropwise at less than 10° C. The temperature, after the addition, was allowed to rise to room temperature and the system stirred there for 60 minutes. Paraformaldehyde (2.0 g) was then added carefully and the mixture stirred at room temperature for 15 minutes. This was followed by the addition of a further amount (15.0 g) of paraformaldehyde at about 20°-26° C. Stirring was continued at this temperature for 2-3 hours further, and then the mixture was drowned into water, stirred for 30 minutes and filtered. The solid 2-bromo-3-nitro-5-acetyl thiophene was washed with water and dried. The yield was 35.3 g (88.25%).

Provenance & Evidence