Potassium Nitrate → 1-Methoxy-2-nitro-5,7,8,9-tetrahydro-6H-benzo[7]annulen-6-one

HRID 2276303Notes

Reaction equation

HRID 2276303 reaction equation
[N+:1]([O-:4])([O-])=[O:2].[K+].[CH3:6][O:7][C:8]1[C:13]2[CH2:14][CH2:15][CH2:16][C:17](=[O:19])[CH2:18][C:12]=2[CH:11]=[CH:10][CH:9]=1>C(#N)C.FC(F)(F)C(OC(=O)C(F)(F)F)=O>[CH3:6][O:7][C:8]1[C:13]2[CH2:14][CH2:15][CH2:16][C:17](=[O:19])[CH2:18][C:12]=2[CH:11]=[CH:10][C:9]=1[N+:1]([O-:4])=[O:2]

Participants

5

Reactant 2

HCID 24434Potassium NitrateHCID 127282361-methoxy-6,7,8,9-tetrahydro-5H-benzo[7]annulen-6-one

Product 1

HCID 1177782541-Methoxy-2-nitro-5,7,8,9-tetrahydro-6H-benzo[7]annulen-6-oneYield 34.6%

Reagents, catalysts & solvents 2

HCID 6342AcetonitrileSolvent2×HCID 9845Trifluoroacetic anhydrideSolvent

Procedure

To potassium nitrate in acetonitrile (50 mL) and trifluoroacetic anhydride (100 mL) at 0° C. was added dropwise 1-methoxy-5,7,8,9-tetrahydro-benzocyclohepten-6-one (25 g, 0.131 mol) in 50 mL acetonitrile. The reaction was stirred for 2.5 hours while warming to RT. The reaction was concentrated without heat on a rotary evaporator. MeOH was added and stirred briefly. Reconcentrated and worked-up by partitioning between dichloromethane and sat. sq. sodium bicarbonate solution. The organic layer was separated and dried (Mg2SO4), concentrated and purified by chromatography ISCO (330 g silica cartridge: gradient elution—10 to 50% EA:HEX over 60 minutes) affording two isomers. The title compound was the later eluting (10.7 grams, 34.6% yield). 1H-NMR (400 MHz, CDCl3) 7.70 (d, J=8.3 Hz, 1H), 7.06 (d, J=8.3 Hz, 1H), 3.92 (s, 3H), 3.80 (s, 2H), 3.13-3.09 (m, 2H), 2.60 (t, J=7.0 Hz, 2H), 2.10-2.03 (m, 2H).

Workup

  1. concentrationThe reaction was concentrated
  2. temperaturewithout heat on a rotary evaporator
  3. additionMeOH was added
  4. stirringstirred briefly
  5. customby partitioning between dichloromethane
  6. customThe organic layer was separated
  7. dry with materialdried (Mg2SO4)
  8. concentrationconcentrated
  9. custompurified by chromatography ISCO (330 g silica cartridge: gradient elution—10 to 50% EA:HEX over 60 minutes)
  10. customaffording two isomers

Sources & evidence

ORD record
ord-365b3f337eb94621b9d5ffec61f37b28
Source dataset
uspto-grants-2015_09
Patent number
US09132128B2

Reaction notes

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