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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 2198294Generated: October 29, 2026

Formaldehyde → 9-(4-fluorophenethyl)-6-chloro-2,3,4,9-tetrahydro-2-methyl-1H-pyrido[3,4-b]indole

https://huagongshe.com/reaction/2198294

Reaction equation

Participants

RoleNameHCIDCharge
ReactantFormaldehydeHCID 712—
ReactantTrifluoroacetic acidHCID 6422—
Reactant2-(1-(4-fluorophenethyl)-5-chloro-1H-indol-3-yl)-N-methylethanamineHCID 66911769—
SolventAcetonitrileHCID 6342—
Product9-(4-fluorophenethyl)-6-chloro-2,3,4,9-tetrahydro-2-methyl-1H-pyrido[3,4-b]indoleHCID 44242176—

Reaction Conditions

Temperature25 °C

Reaction Steps

The title compound was prepared by General Method 4. 2-(1-(4-fluorophenethyl)-5-chloro-1H-indol-3-yl)-N-methylethanamine (600 mg) was dissolved in acetonitrile (10 mL) containing 5% TFA and the reaction mixture was heated to reflux. 37% aqueous formaldehyde (0.17 mL) was added and the reflux was continued for 15-20 min. The reaction mixture was cooled to 25° C., concentrated under reduced pressure and partitioned between ethyl acetate and satd. Aqueous NaHCO3. The organic layer was dried over sodium sulfate, evaporated under reduced pressure and the residue was purified by silica gel chromatography (eluent 6% methanol-chloroform) to obtain 170 mg of product. The free base was converted into its HCl salt by treatment of HCL-ether. 1H NMR (CDCl3) δ 13.1 (s, 1H), 7.25-7.1 (m, 3H), 6.8 (m, 2H), 6.7 (m, 2H), 4.4 (m, 1H), 4.2 (m, 1H), 3.9 (m, 1H), 3.4 (m, 1H), 3.2-3.0 (m, 3H), 2.8 (m, 3H), 2.6 (s, 3H). MS m/z observed 343. HPLC RT 5.16 min.

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS08338447B2
Source datasetuspto-grants-2012_12
ORD IDord-09ec5875feaf483286f5e8533ef7112f
Source noteuspto-grants-2012_12