Acetic Acid Mixture with Hydrobromic Acid → 3(S)-[1(R)-carboxy-6-(4-piperidyl)hexyl]amino-4-oxo-2,3,4,5-tetrahydro-1,5-benzoxazepine-5-acetic acid

To a solution of tert-butyl 3(S)-[6-(1-benzyloxycarbonyl-4-piperidyl)-1(R)-ethoxycarbonylhexyl]amino-4-oxo-2,3,4,5-tetrahydro-1,5-benzoxazepine-5-acetate (0.35 g) in acetic acid (1 ml) is added 30% hydrogen bromide-acetic acid solution (2 ml). The resulting mixture is allowed to stand for 1 hour at room temperature and then diluted with ethyl ether (100 ml). The supernatant layer is removed by decantation and the precipitate is dissolved in 1N sodium hydroxide solution (10 ml). The solution is allowed to stand for 60 minutes at room temperature. After addition of acetic acid (1 ml), the mixture is chromatographed on MCI gel using water-methanol (1:2) as an eluent. The eluate is concentrated in vacuo and lyophilized to give 3(S)-[1(R)-carboxy-6-(4-piperidyl)hexyl]amino-4-oxo-2,3,4,5-tetrahydro-1,5-benzoxazepine-5-acetic acid (0.13 g) as colorless powder.

1. customThe supernatant layer is removed by decantation
2. dissolutionthe precipitate is dissolved in 1N sodium hydroxide solution (10 ml)
3. waitto stand for 60 minutes at room temperature
4. additionAfter addition of acetic acid (1 ml)
5. customthe mixture is chromatographed on MCI gel
6. concentrationThe eluate is concentrated in vacuo

ORD record

ord-abda4cb630344befa93c2dae55f47a3f

Source dataset

uspto-grants-1985_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04548932