18791-99-6

The general procedure for the synthesis of 4-bromothiophene-2-carbonitrile from 4-bromo-2-thiophenecarboxaldehyde was as follows: 4-bromothiophene-2-carboxaldehyde (600 g, 3.14 mmol) and hydroxylamine hydrochloride (438 g, 6.30 mmol) were dissolved in pyridine (5 L). After the reaction mixture was cooled to room temperature, it was heated to 90 °C and maintained for 10 min. Subsequently, acetic anhydride (1940 g, 19.0 mmol) was slowly added dropwise and the reaction system was heated to 80°C for 1 hour. After completion of the reaction, the mixture was poured into water (20 L) and stirred for 30 min. After filtration and drying, the target product 4-bromothiophene-2-carbonitrile (564 g, 95% yield) was obtained.

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