7-Bromo-1-hydroxyisoquinoline

Uses

7-Bromo-1-hydroxyisoquinoline acts as a pharmaceutical intermediate. It is also used to prepare 1-amino-4-bromoisoquinoline.

Synthesis

7-Bromo-1-chloroisoquinoline (1a, 2.70 g, 11.10 mmol) was used as starting material, which was dissolved in acetic acid (50 mL), followed by the addition of ammonium acetate (1b, 8.50 g, 111.10 mmol). The reaction mixture was placed in an oil bath at 100 °C and the reaction was stirred for 4 hours. After completion of the reaction, the reaction mixture was concentrated to dryness by rotary evaporator. An appropriate amount of water was added to the residue and a white solid precipitated. The solid product was collected by filtration and washed with water to afford 7-bromoisoquinolin-1(2H)-one (1c, 2.7 g, white solid). The crude product was used directly in the subsequent reaction without further purification. Mass spectrum (ESI) m/z: 225.9 [M + 1]+. 1H NMR (400 MHz, CDCl3) δ: 8.55 (d, J = 1.8 Hz, 1H), 7.75 (dd, J = 2.1, 8.5 Hz, 1H), 7.43 (d, J = 8.6 Hz, 1H), 7.14 (d, J = 6.2 Hz, 1H), 6.52 ( d, J = 7.3 Hz, 1H).

References

[1] Chemical Communications, 2018, vol. 54, # 75, p. 10574 - 10577
[2] Patent: EP3042907, 2016, A1. Location in patent: Paragraph 0324; 0325