5-Chloroindole-3-carboxaldehyde

Yellow to beige solid

Phosphorus oxychloride (0.7 mL, 7.6 mmol) was added dropwise into anhydrous DMF (2.3 mL) and stirred at room temperature for 10 minutes. A solution of 5-chloroindole (0.76 g, 5.0 mmol) in anhydrous DMF (0.8 mL) was added dropwise and the reaction stirred for 75 minutes at room temperature. Ice (2.7 g) was added to the mixture, followed by an aqueous NaOH solution (2.8 g in 7.5 mL of water) and the reaction was heated to 100 C for 8 minutes. The reaction mixture was cooled and diluted with water (30 mL) and extracted with ethyl acetate. The organics were washed with brine, dried (MgSOGeneral procedure: A 50 mL round-bottomed flask equipped with a magnetic stirringbar was charged with the appropriate indole 1 (0.5 mmol, 1.0 equiv), 37percent aq HCHO (0.5 mmol, 0.0406 g, 1.0 equiv), 25percent aqNH3 (1.0 mmol, 0.0681 g, 2.0 equiv), FeCl3 (0.01 mmol, 0.0016 g, 2 molpercent), and DMF (2 mL). The flask was fitted with a reflux condenser, and the mixture was stirred at 130 °C under open air.When the reaction was complete (TLC), the mixture was cooledto r.t., diluted with sat. aq NaCl (10 mL) and 0.5 M aq HCl (2 mL), and extracted with EtOAc (3 x 7 mL). The organic layers werecombined, washed with sat. aq NaHCO3 (10 mL) and sat. aq NaCl(10 mL), dried (Na2SO4), and concentrated under reduced pressure.The residue was purified by flash column chromatography(silica gel, hexane–EtOAc).General procedure: A method for synthesizing compound III-1 wherein R1, R2 and R3 are simultaneously hydrogen in the formula III, the method comprising the steps of:(1) Add to a 50 mL round bottom flask1.0mmol indole(In the formula I, R1, R2, and R3 are both hydrogen) and1.0 mmol (0.140 g) of hexamethylenetetramine, then 2 mL of N, N-dimethylformamide (DMF), stirred in a magnetic stirrer to dissolve the solid, followed by the addition of 0.05 mmol (0.012 g) of crystalline trichloride Aluminum, connected to a reflux condenser, heated at 120 ° C, the reaction progress was monitored by TLC, and the reaction was cooled to room temperature after 1 h to prepare a suspension;(2) The suspension prepared in the step (1) is suction filtered with a funnel padded with diatomaceous earth.The filter cake was washed well with ethyl acetate, suction filtered, and the above operation was repeated until the filtrate had no product, and all the filtrates were combined.Dilute with 15 mL of saturated saline solution, disperse and separate the layers, and the aqueous layer was further extracted with ethyl acetate three times.Each time 10 mL, the ethyl acetate layer was combined and washed with 10 mL of 2 mol/L diluted hydrochloric acid.Wash with 10 mL of saturated sodium bicarbonate solution, and finally wash with 10 mL of saturated brine.The washed ethyl acetate layer was dried over anhydrous sodium sulfate, and after drying, the desiccant was filtered off.Then use a rotary evaporator to recover the solvent to concentrate the product, and finally, The residue is subjected to silica gel column chromatography using a mixture of n-hexane-ethyl acetate (V/V = 2:1) as an eluent to obtain a purified product.The mass of the compound III-indole-3-carbaldehyde is 0.137g, The product yield was 94percent.5-Chloroindole-3-carboxaldehyde

Molecular Weight:179.60
XLogP3:2.3
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:1
Rotatable Bond Count:1
Exact Mass:179.0137915
Monoisotopic Mass:179.0137915
Topological Polar Surface Area:32.9
Heavy Atom Count:12
Complexity:185
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes