1-Chloroethyl chloroformate → 4-(1-Benzofuran-2-yl)-1,2,3,6-tetrahydropyridine

HRID 1940551Notes

Reaction equation

HRID 1940551 reaction equation
[NH:1]1[CH:6]=[CH:5][CH2:4][CH2:3][CH2:2]1.Cl[CH:8]([O:10][C:11](Cl)=O)[CH3:9]>ClCCl>[O:10]1[C:11]2[CH:2]=[CH:3][CH:4]=[CH:5][C:6]=2[CH:9]=[C:8]1[C:4]1[CH2:5][CH2:6][NH:1][CH2:2][CH:3]=1

Participants

4

Reactant 2

HCID 5213051-Chloroethyl chloroformateHCID 10176084Tetrahydropyridine

Product 1

HCID 223269354-(1-Benzofuran-2-yl)-1,2,3,6-tetrahydropyridine

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of the foregoing tetrahydropyridine (1.1 g, 3.8 mmol) in dichloromethane (50 ml) at 0° C. was added 1-chloroethylchloroformate (493 μl, 4.6 mmol), keeping the temperature below 0° C. The reaction was allowed to warm to room temperature over 1 hr, after which the solvent was evaporated. Methanol (50 ml) was added to the residue and the mixture heated under reflux for 2 hrs. The solvent was removed by evaporation, and the residue chromatographed on silica, eluting with dichloromethane/methanol/ammonia (90:10:1), to yield the title compound as a buff solid (600 mg, 79%); δH (CDCl3) 2.44-2.48 (2H, m, tetrahydropyridinyl CH2), 3.14 (2H, t, J 5.8 Hz, tetrahydropyridinyl CH2), 3.60-3.63 (2H, m, tetrahydropyridinyl CH2), 6.54-6.58 (2H, m, CH=CR, 3'-H), 7.16-7.26 (2H, m, 5'-H, 6'-H), 7.42 (1H, d, J 7.8 Hz, 7'-H), and 7.50 (1H, d, J 7.2 Hz, 4'-H).

Workup

  1. customthe temperature below 0° C
  2. customafter which the solvent was evaporated
  3. additionMethanol (50 ml) was added to the residue
  4. temperaturethe mixture heated
  5. temperatureunder reflux for 2 hrs
  6. customThe solvent was removed by evaporation
  7. customthe residue chromatographed on silica
  8. washeluting with dichloromethane/methanol/ammonia (90:10:1)

Sources & evidence

ORD record
ord-671035ed90194204920e795055f3d6d9
Source dataset
uspto-grants-1997_12
Patent number
US05700809

Reaction notes

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