Yield:153291-12-4 94%

Reaction Conditions:

with caesium carbonate in N,N-dimethyl-formamide at 0 - 20; for 16 h;

Steps:

2.A Step A: (6-bromo-naphthalen-2-yloxy)-acetic acid ethyl ester

6-bromo-naphthalen-2-ol (1.0 g, 4.48 mmol) was dissolved in 20 mL of DMF and cooled to 0°C. Cs2CO3 (1.75g, 5.38 mmol) and bromoacetic acid ethyl ester (0.75 g, 4.48 mmol) were added thereto, and the mixture was stirred atroom temperature for 16 hours. Water was added to the reaction solution, and the solution was extracted with EtOActo separate an organic layer. The organic layer was dried with MgSO4 and purified by column chromatography to obtainthe title compound (1.3 g, 94 %).1H-NMR (CDCl3) δ 7.93 (1H, s), 7.70 (1H, d), 7.60 (1H, d), 7.50 (1H, d), 7.24 (1H, d), 7.04 (1H, s), 4.72 (2H, s), 4.29(2H, q), 1.29 (3H, t)

References:

EP3239143,2017,A2 Location in patent:Paragraph 0067