Ammonium formate → Ethyl 2-(2-hydroxy-6,7,8,9-tetrahydropyrido[1,2-a]indol-9-yl)acetate

HRID 1964160Notes

Reaction equation

HRID 1964160 reaction equation
C([O:8][C:9]1[CH:10]=[C:11]2[C:15](=[CH:16][CH:17]=1)[N:14]1[CH2:18][CH2:19][CH2:20][C:21](=[CH:22][C:23]([O:25][CH2:26][CH3:27])=[O:24])[C:13]1=[CH:12]2)C1C=CC=CC=1.C([O-])=O.[NH4+]>C1COCC1.CO.[OH-].[Pd+2].[OH-]>[OH:8][C:9]1[CH:10]=[C:11]2[C:15](=[CH:16][CH:17]=1)[N:14]1[CH2:18][CH2:19][CH2:20][CH:21]([CH2:22][C:23]([O:25][CH2:26][CH3:27])=[O:24])[C:13]1=[CH:12]2

Participants

5

Reactant 2

HCID 2723923Ammonium formateHCID 67249894Ethyl 2-(2-(Benzyloxy)-7,8-dihydropyrido[1,2-a]indol-9(6H)-ylidene)acetate

Product 1

HCID 67249257Ethyl 2-(2-hydroxy-6,7,8,9-tetrahydropyrido[1,2-a]indol-9-yl)acetateYield 87.4%

Reagents, catalysts & solvents 2

HCID 9942167Palladium hydroxideCatalystHCID 21899815MeOH tetrahydrofuranSolvent

Procedure

Ethyl 2-(2-(benzyloxy)-7,8-dihydropyrido[1,2-a]indol-9(6H)-ylidene)acetate (608 mg, 1.682 mmol) was dissolved in THF/MeOH (1:1) (4 mL). Ammonium formate (648 mg, 10.28 mmol) and palladium hydroxide (20 wt % Pd on carbon) (60 mg) was added under nitrogen protection. The reaction was heated at reflux for 5 h. The solid was filtered. The filtrate was concentrated, dissolved in ethyl acetate, washed with water, dried over anhydrous Na2SO4, and concentrated. The residue was purified by silica gel column chromatography to give the title compound (402 mg) as colorless oil. LCMS m/z=274.3 [M+H]+; 1H NMR (400 MHz, CDCl3) δ ppm 1.32 (t, J=7.1 Hz, 3H), 1.50-1.61 (m, 1H), 1.98-2.08 (m, 1H), 2.08-2.22 (m, 2H), 2.55 (dd, J=15.6 and 8.7 Hz, 1H), 2.94 (dd, J=15.6, 5.5 Hz, 1H), 3.44-3.52 (m, 1H), 3.80-3.88 (m, 1H), 4.07-4.13 (m, 1H), 4.24 (q, J=7.1 Hz, 2H), 4.95 (s, 1H), 6.12 (s, 1H), 6.74 (dd, J=8.6, 2.4 Hz, 1H), 6.95 (d, J=2.4 Hz, 1H), 7.10 (d, J=8.6 Hz, 1H).

Workup

  1. temperatureThe reaction was heated
  2. temperatureat reflux for 5 h
  3. filtrationThe solid was filtered
  4. concentrationThe filtrate was concentrated
  5. dissolutiondissolved in ethyl acetate
  6. washwashed with water
  7. dry with materialdried over anhydrous Na2SO4
  8. concentrationconcentrated
  9. customThe residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-ab9ab7f895d347828668183d7e4ea8a7
Source dataset
uspto-grants-2013_04
Patent number
US08415484B2

Reaction notes

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