Hydrochloric Acid → Ethyl (6bR,10aS)-2,3,6b,9,10,10a-hexahydro-3-methyl-1H-pyrido(3',4':4,5)pyrrolo(1,2,3-de)quinoxaline-8(7H)-carboxylate

HRID 1764806Notes

Reaction equation

HRID 1764806 reaction equation
B.[CH3:2][N:3]1[C:12]2[CH:11]=[CH:10][CH:9]=[C:8]3[C@@H:13]4[CH2:18][N:17]([C:19]([O:21][CH2:22][CH3:23])=[O:20])[CH2:16][CH2:15][C@@H:14]4[N:6]([C:7]=23)[CH2:5][C:4]1=O.Cl>O1CCCC1>[CH3:2][N:3]1[C:12]2[CH:11]=[CH:10][CH:9]=[C:8]3[C@@H:13]4[CH2:18][N:17]([C:19]([O:21][CH2:22][CH3:23])=[O:20])[CH2:16][CH2:15][C@@H:14]4[N:6]([C:7]=23)[CH2:5][CH2:4]1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 6331BoraneHCID 21302625(6bR,10aS)-Ethyl 3-methyl-2-oxo-2,3,6b,7,10,10a-hexahydro-1H-pyrido[3',4':4,5]pyrrolo[1,2,3-de]quinoxaline-8(9H)-carboxylate

Product 1

HCID 21302624Ethyl (6bR,10aS)-2,3,6b,9,10,10a-hexahydro-3-methyl-1H-pyrido(3',4':4,5)pyrrolo(1,2,3-de)quinoxaline-8(7H)-carboxylateYield 93%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

A solution of borane in tetrahydrofuran (1M, 33 mL, 33 mmol) was added dropwise to a stirred solution of ethyl (6bR, 10aS)-3-methyl-2-oxo-2,3,6b,9,10,10a-hexahydro-1H-pyrido[3′,4′:4,5]pyrrolo[1,2,3-de]quinoxaline-8(7H)-carboxylate (5.24 g, 16.6 mmol) in anhydrous tetrahydrofuran (25 mL) under nitrogen. After the addition was complete, the mixture was stirred and heated at reflux for 1 h, cooled and treated with 6N hydrochloric acid (15 mL). It was then heated under reflux for 30 min, cooled and evaporated to dryness under reduced pressure. The residue was dissolved in a minimum quantity of water and the solution basified with 1N sodium hydroxide and extracted with dichloromethane (2×). The extract was washed with water, dried over magnesium sulfate, and concentrated to yield 4.65 g (93%) of ethyl (6bR,10aS)-3-methyl-2,3,6b,9,10,10a-hexahydro-1H-pyrido[3′,4′:4,5]pyrrolo[1,2,3-de]quinoxaline-8(7H)-carboxylate as a viscous liquid. 1H NMR (CDCl3, 300 MHz) δ 1.28 (t, J=7 Hz, 3H), 1.68-1.78 (m, 1H), 1.78-1.93 (m, 2H), 2.81-2.90 (m, 2H), 2.86 (s, 3H), 3.05-3.26 (m, 2H), 3.26-3.38 (m, 2H), 3.56-3.75 (m, 2H), 3.79-3.87 (m, 1H), 4.16 (q, J=7 Hz, 2H), 6.41 (d, J=8.1 Hz, 1H), 6.61 (d, J=8.1 Hz, 1H), 6.67 (t, J=8.1 Hz, 1H) ppm. MS (CI): 302 (M+H+).

Workup

  1. additionAfter the addition
  2. temperatureheated
  3. temperatureat reflux for 1 h
  4. temperaturecooled
  5. temperatureIt was then heated
  6. temperatureunder reflux for 30 min
  7. temperaturecooled
  8. customevaporated to dryness under reduced pressure
  9. dissolutionThe residue was dissolved in a minimum quantity of water
  10. extractionextracted with dichloromethane (2×)
  11. washThe extract was washed with water
  12. dry with materialdried over magnesium sulfate
  13. concentrationconcentrated

Sources & evidence

ORD record
ord-189ca9a18a0b4a9eb40333ca5f9a70b6
Source dataset
uspto-grants-2007_06
Patent number
USRE039680E1

Reaction notes

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