51114-73-9

67857-97-0

51114-73-9

The general procedure for the synthesis of 5-nitro-α-tetralone from 4-(2-nitrophenyl)butyric acid was as follows: first, 1 g of 4-(2-nitrophenyl)butyric acid (NPBS, 4.78 mmol) and 18 g of trifluoromethanesulfonic acid (TFMS) were added to a 100 mL two-necked flask fitted with a reflux condenser and magnetic stirrer at 20 °C. Under stirring, the reaction mixture was placed in an oil bath preheated to 130 °C and stirred continuously at this temperature for 45 min. Upon completion of the reaction, the mixture was cooled and transferred to a microdistillation unit. Most of the excess TFMS was removed by distillation at 52 °C and 0.5 mbar.After distillation, the bottom residue contained 0.914 g of 5-nitro-3,4-dihydro-1(2H)-naphthalenone and 3.44 g of TFMS (as determined by the GC-ISTD/internal standard method) in 99.3% yield, with 100% conversion to NPBS and 99.3% selectivity.