4-Fluoro-2-methyl-5-(phenylmethoxy)-1H-indole synthesis

Yield:649736-47-0 80%

Reaction Conditions:

with hydrazine;nickel in methanol at 20 - 40; for 1.5 h;Heating / reflux;

Steps:

2.H

A mixture of 1-(3-benzyloxy-2-fluoro-6-nitrophenyl)-propan-2-one (9.09 g, 30 mmol) and Raney nickel (5 g) in methanol (100 ml) was heated to 40 C and then a solution of hydrazine in methanol (15 mL) was added dropwise with vigorous stirring over a period of 30 min. After refluxing for 1 h, the reaction mixture was cooled to room temperature, filtered through Celite and concentrated. The crude material was passed through a pad of silica gel eluting with dichloromethane and concentrated in vacuo to provide 5-benzyloxy-4-fluoro-2-methyl-1H-indole (6.1 g, 80 %) as a yellowish oil. LC/MS; (M+H) + = 256. 3+

References:

WO2004/9542,2004,A2 Location in patent:Page 38