1H-Indole-2-carboxaldehyde, oxime synthesis

Yield:881853-73-2 86%

Reaction Conditions:

with hydroxylamine hydrochloride;sodium hydroxide in ethanol;water at 20; for 2 h;

Steps:

5B Exam - l H-indole-2-carbaldehvde oxime (B-105

A mixture of lH-indole-2-carbaldehyde (2 g, 13.8 mmol), hydroxylamine hydrochloride (1.44 g, 20.7 mmol) and sodium hydroxide (0.83 g, 20.7 mmol) in 50% ethanol/water (30 mL) was stirred at room temperature for 2 hours. On completion, the mixture was concentrated to remove most of ethanol and then extracted with dichloromethane. The organic layer was concentrated and purified by column chromatography [petroleum ether/ethyl acetate=2: l] to give compound B-105 (1.9 g, 86% yield) as a white solid. LCMS: (ES+) m/z (M+H)⁺ =161.1 , tR=l .060.

References:

WO2015/66371,2015,A1 Location in patent:Paragraph 00210-00211