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US 5,710,336 AGranted
Process for the preparation of 5-6-dihydroxy-2-amino-1, 2, 3, 4-tetrahydronaphthalene derivatives
AssigneeChiesi Farmaceutici S.p.A.
InventorsPaolo Chiesi, Paolo Ventura, Vittorino Servadio, Maurizio Del Canale, Renato De Fanti, Gabriele Amari
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Abstract
A process, and variations thereof, for the preparation of 5,6-dihydroxy-2-amino-1,2,3,4-tetrahydronaphthalene derivatives of formula (I), wherein R.sub.1, R.sub.2, R.sub.3 can independently be hydrogen or lower alkyl.
Claims8
A process for preparation of a compound of the formula (I):
- ##STR7## wherein:
- wherein:
- R.sub.1 is lower alkyl;
- R.sub.2 and R.sub.3 are each hydrogen, which process comprises:
- a) cyclizing 2-alkylamino-4-(2,3-dialkoxy-phenyl)butyric acid with simultaneous dealkylation on oxygen, thereby producing in a single step salified 2-alkylamino-5,6-dihydroxy-1-tetralone;
- and
- b) catalytically reducing said tetralone, thereby producing said compound of the formula (I).
4 more elements
Dependencies are inferred from the claim text.