2-formyl-1H-Indole-5-carboxylic acid methyl ester synthesis

Yield:880360-85-0 85%

Reaction Conditions:

with manganese(IV) oxide in chloroform; for 14 h;

Steps:

3

To a stirring solution of intermediate 2, 2-hydroxymethyl-1H-indole-5-carboxylic acid methyl ester (4.7 g, 23.1 mmol) in 70 mL of chloroform was added in two portions MnO₂ (12.5 g, 115.4 mmol). After 14 hr the reaction was filtered through a plug of celite and then concentrated under reduced pressure to give the title compound (4.0 g, 85% yield) as a brown oil. This material was used without further purification. Rf=0.21 (20% EtOAc/hexanes); Anal Clcd for C₁₁H₁₁NO₃: Exact Mass: 203.06; obsd LRMS APCI (M-1) m/z 202.

References:

US2006/69087,2006,A1 Location in patent:Page/Page column 14