2-Naphthalenecarboxylicacid,2-amino-1,2,3,4-tetrahydro-8-hydroxy-,(S)-(9CI) synthesis

Yield:-

Reaction Conditions:

with hydrogenchloride in 1,4-dioxane;

Steps:

2.2.b EXAMPLE 2.2.b

EXAMPLE 2.2.b A suspension of 9.2 g (29.55 mmol) of (S)-2-benzamido-8-hydroxy-1,2,3,4-tetrahydro-naphthalene-2-carboxylic acid in 45 ml of dioxan and 62 ml of 25% hydrochloric acid was heated to 100° in a bomb tube for 24 hours, then cooled, concentrated to half of the volume and extracted with ethyl acetate. The organic phase was washed with water, whereupon the combined aqueous phases were reduced to a volume of 200 ml and adjusted to pH 7 with concentrated ammonia solution. The solution obtained was filtered over MCl gel (CHP20P; 75-150μ) (water, water/methanol (95:5)→water/methanol (9:1)), whereupon after drying over SICAPENT 5.30 g (86.6%) of (S)-2-amino-8-hydroxy-1,2,3,4-tetrahydro-naphthalene-2-carboxylic acid were obtained. M.p. >270° (dec.). [α]_D =+7.0° (c=0.2, 0.1N HCl).

References:

US5837807,1998,A