Methyl 3-amino-2-chloro-5-fluoro-4-methylbenzoate → 2,3-Dichloro-5-fluoro-4-methylbenzoic acid

Beteiligte Stoffe

Reaktionsschritte

8 g of methyl 3-amino-2-chloro-5-fluoro-4-methylbenzoate are diazotized with NaNO2 /HCl in aqueous solution. This diazonium salt solution is added dropwise to a solution of 4.1 g of CuCl in 16 ml of concentrated HCl. The mixture is then warmed until no further gas is formed. After cooling, the solid which has precipitated is separated off and taken up in 30 ml of 50% strength EtOH. After addition of 2.3 g of NaOH, the mixture is boiled for 1 hour. After cooling to room temperature, the mixture is acidified with HCl and the solid which has precipitated is isolated. Melting point: 179°-80°. Yield: 5.2 g.

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