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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 1775913Generated: 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/1775913

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 numberUS09260429B2
Source datasetuspto-grants-2016_02
ORD IDord-65e5f85bf9f248c89efa65fede3e76bc
Source noteuspto-grants-2016_02