Formaldehyde → 1,2,3,4-Tetrahydro[1]benzothieno[2,3-c]pyridine

HRID 501210

Reaction equation

HRID 501210 reaction equation
Cl.[S:2]1[CH:6]=[C:5]([CH2:7][CH2:8][NH2:9])[C:4]2[CH:10]=[CH:11][CH:12]=[CH:13][C:3]1=2.[CH2:14]=O>CO>[CH2:14]1[C:6]2[S:2][C:3]3[CH:13]=[CH:12][CH:11]=[CH:10][C:4]=3[C:5]=2[CH2:7][CH2:8][NH:9]1

Participants

4

Reactant 2

HCID 712FormaldehydeHCID 209554Benzo(b)thiophene-3-ethylamine, hydrochloride

Product 1

HCID 4132821,2,3,4-Tetrahydro[1]benzothieno[2,3-c]pyridineYield 36.1%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of 2-(benzo[b]thien-3-yl)ethylamine hydrochloride (0.5 g, 2.34 mmol) and paraformaldehyde (0.125 g, 4.16 mmol) in methanol (15 mL) was refluxed for 24 h. The reaction mixture was concentrated under reduce pressure and the residue was neutralized with saturated NaHCO3 (50 mL), and extracted with ethyl acetate (2×50 mL). The organic layer was dried over anhydrous sodium sulfate, filtered and concentrated to furnish 1,2,3,4-tetrahydro[1]benzothieno[2,3-c]pyridine (160 mg, 35%); 1H NMR (200 MHz, CDCl3): δ 2.81 (m, 2H), 3.25 (m, 2H), 4.15 (s,2H), 7.30 (m, 2H), 7.69 (d, J=4.0 Hz, 1H), 7.79 ((d, J=4.0 Hz, 1H).

Workup

  1. temperaturewas refluxed for 24 h
  2. concentrationThe reaction mixture was concentrated
  3. extractionextracted with ethyl acetate (2×50 mL)
  4. dry with materialThe organic layer was dried over anhydrous sodium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-4ae6b99d74d845389947fddfde6d1c34
Source dataset
uspto-grants-2010_08
Patent number
US07772245B2

Linked notes

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