Hydrogen Bromide → (2-Amino-4,5,6,7-tetrahydrothieno[2,3-c]pyridin-3-yl)phenylmethanone

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Reaction Steps

To a cooled and stirred suspension of protected 2-amino-3-benzoyl-6-benzyloxycarbonyl-4,5,6,7-tetrahydrothieno[2,3-c]pyridine (0.01 mol) in acetic acid (2 mL), as prepared in Example 7, was added a solution of HBr (33%) in acetic acid (10 mL). After stirring at room temperature for 4 h (TLC control), n-hexane was added and the resulting suspension was evaporated under vacuum to give a solid which was dissolved in water (10 mL) and neutralized with NaOH (5% solution). The precipitated solid was chromatographed on a silica gel column eluting with an ethyl acetate and petroleum ether mixture to give 2-amino-3-benzoyl-4,5,6,7-tetrahydrothieno[2,3-c]pyridine. (m.p.160-162° C., 92% yield). 1H-NMR (CDCl3): 1.86 (m, 1 H); 1.95 (m, 2H); 2.79 (t, 2H); 3.79 (s, 2H).

Provenance & Evidence