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

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Reaction Steps

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).

Provenance & Evidence