Reaction #816416

Reaction equation

13

N-acetyl-7-nitro-1,2,3,4-tetrahydroisoquinoline

hydrazine hydrate

→

compound 14

Yield 86.8%

N-acetyl-7-amino-1,2,3,4-tetrahydroisoquinoline

Yield 86.8%

Solvents

methanol

Conditions

Workup

1. 1
   Temperatureunder refluxing for 20 minutes
2. 2
   Temperaturethe mixture is refluxed for an additional 4 h
3. 3
   Temperaturecooled
4. 4
   Filtrationfiltered
5. 5
   Washthe residue washed with methanol
6. 6
   ConcentrationThe filtrate is concentrated in vacuo
7. 7
   Otherthe residue recrystallized from EtOAc

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).

Source