Hydrazine hydrate (1:1) → 1-(7-Amino-3,4-dihydroisoquinolin-2(1H)-yl)ethan-1-one

HRID 729234Notes

Reaction equation

HRID 729234 reaction equation
[C:1]([N:4]1[CH2:13][CH2:12][C:11]2[C:6](=[CH:7][C:8]([N+:14]([O-])=O)=[CH:9][CH:10]=2)[CH2:5]1)(=[O:3])[CH3:2].O.NN>CO>[C:1]([N:4]1[CH2:13][CH2:12][C:11]2[C:6](=[CH:7][C:8]([NH2:14])=[CH:9][CH:10]=2)[CH2:5]1)(=[O:3])[CH3:2]

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 64254731-(7-Nitro-3,4-dihydroisoquinolin-2(1H)-yl)ethanone

Product 1

HCID 128113521-(7-Amino-3,4-dihydroisoquinolin-2(1H)-yl)ethan-1-oneYield 86.8%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of 13 (5.1 g, 23 mmol), activated carbon (4.2 g), ferric chloride hexahydrate (2.1 g, 7.6 mmol) and methanol (140 ml) is stirred under refluxing for 20 minutes. To the boiling mixture is added hydrazine hydrate (8.5 g, 265 mmol) dropwise, and the mixture is refluxed for an additional 4 h, cooled and filtered and the residue washed with methanol. The filtrate is concentrated in vacuo and the residue recrystallized from EtOAc to give compound 14 (3.8 g, 85% yield). 1H NMR [300 MHz, (CD3)2SO], a 3:2 mixture of amide conformers doubling most signals, δ 6.80 (1H, d, H-5), 6.40 (1H, d, H-6), 6.33 (1H, s, H-7), 4.89 (2H, br s, NH2), 4.46 (0.8H, s, ArCH2N), 4.41 (1.2H, s, ArCH2N), 3.57 (2H, t, ArCH2CH2N), 2.66 (1.2H, t, ArCH2CH2N), 2.55 (0.8H, t, ArCH2CH2N), 2.06 (1.2H, s, COCH3), 2.05 (1.8H, s COCH3).

Workup

  1. temperatureunder refluxing for 20 minutes
  2. temperaturethe mixture is refluxed for an additional 4 h
  3. temperaturecooled
  4. filtrationfiltered
  5. washthe residue washed with methanol
  6. concentrationThe filtrate is concentrated in vacuo
  7. customthe residue recrystallized from EtOAc

Sources & evidence

ORD record
ord-10052024dbfd4794a38efb33a52ab770
Source dataset
uspto-grants-2009_09
Patent number
US07582616B2

Reaction notes

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