Indole-5-carboxylic acid synthesis
- Product Name:Indole-5-carboxylic acid
- CAS Number:1670-81-1
- Molecular formula:C9H7NO2
- Molecular Weight:161.16
10075-50-0
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124-38-9
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1670-81-1
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$6.00/250mg
Yield:1670-81-1 65%
Reaction Conditions:
Stage #1: 5-bromo-1H-indolewith isopropylmagnesium chloride in tetrahydrofuran at 0; for 0.166667 h;
Stage #2: with n-butyllithium in tetrahydrofuran;hexane at -20; for 0.5 h;
Stage #3: carbon dioxide in tetrahydrofuran;hexane at -20; for 0.5 h;
Steps:
1H-Indole-5-carboxylic acid (3d)
To a solution of 5-Bromo-1H-indole (0.86 g, 4.4 mmol, 1.0 equiv.) in dryTHF (20 mL) at 0 C was added a 2 M solution of i-PrMgCl in THF (2.2 mL, 4.4 mmol, 1 equiv.) during5 min. The clear solution was stirred at that temperature for an additional 5 min, and a 2.5Msolution ofn-BuLi in hexanes (3.5 mL, 8.8 mmol, 2.0 equiv.) was added dropwise during 5 min, while maintainingthe temperature below 20 C. The resulting mixture was stirred at that temperature for 0.5 h, dry CO2(0.2 g, 4.4 mmol, 1.0 equiv.) was added to 20 C. The resulting mixture was warmed to 20 C in0.5 h and quenched with water (6 mL). After stirring the mixture below for 10 min, the phases wereseparated and the water phase was extracted one additional time with ethyl acetate. The resultingsuspension was allowed to reach room temperature and fitered through a 0.5 1 cm pad of silicagel eluted with 10 mL of ethyl acetate. The ltrate was concentrated and the residue was puried byflash chromatography on silica gel (eluent: petroleum ether/ethyl acetate = 3:1) to afford product 3das off-white solid, 0.46 g (yield: 65%), m.p.: 210-214 C. 1H-NMR (600 MHz, DMSO) 12.39 (s, 1H),11.46 (s, 1H), 8.25 (s, 1H), 7.72 (dd, J = 8.5, 1.5 Hz, 1H), 7.45 (dd, J = 8.4, 5.7 Hz, 2H), 6.57 (s, 1H).13C-NMR (151 MHz, DMSO) 168.90, 138.80, 127.64, 127.35, 123.28, 122.67, 121.87, 111.57, 102.93.
References:
Tian, Qingqiang;Shang, Suqin;Wang, Huajun;Shi, Guoqiang;Li, Zhiyao;Yuan, Jianyong [Molecules,2017,vol. 22,# 11,art. no. 1952] Location in patent:supporting information
1011-65-0
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$6.00/250mg
1670-81-1
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$6.00/250mg
1075-25-8
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$73.00/250mg
1670-81-1
333 suppliers
$6.00/250mg
16066-91-4
183 suppliers
$8.00/250mg
124-38-9
121 suppliers
$214.00/14L
1670-81-1
333 suppliers
$6.00/250mg
124-38-9
121 suppliers
$214.00/14L
144104-59-6
232 suppliers
$20.00/1g
1670-81-1
333 suppliers
$6.00/250mg