1,4-dithia-7-azaspiro [4.4]nonane-8(S)-carboxylic acid, methyl ester hydrobromide → Methyl (8S)-1,4-dithia-7-azaspiro[4.4]nonane-8-carboxylate

HRID 2417770Notes

Reaction equation

HRID 2417770 reaction equation
Br.[CH3:2][O:3][C:4]([C@@H:6]1[CH2:14][C:9]2([S:13][CH2:12][CH2:11][S:10]2)[CH2:8][NH:7]1)=[O:5]>[OH-].[Na+]>[CH3:2][O:3][C:4]([C@@H:6]1[CH2:14][C:9]2([S:10][CH2:11][CH2:12][S:13]2)[CH2:8][NH:7]1)=[O:5]

Participants

3

Reactant 1

HCID 132746721,4-dithia-7-azaspiro [4.4]nonane-8(S)-carboxylic acid, methyl ester hydrobromide

Product 1

HCID 13274671Methyl (8S)-1,4-dithia-7-azaspiro[4.4]nonane-8-carboxylate

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent

Procedure

Dissolve the 1,4-dithia-7-azaspiro[4.4]nonane-8(S)-carboxylic acid methyl ester hydrobromide from paragraph B in 0.1 N NaOH and extract with ethyl acetate. Dry the organic layer over magnesium sulfate and concentrate in vacuo to give 1,4-dithia-7-azaspiro[4.4]nonane-8(S)-carboxylic acid methyl ester (1.35 g). Dissolve the latter in 100 ml of ethyl acetate and treat with 2.07 g of N-benzyloxycarbonyl-(S)-alanine, N-hydroxysuccinimide ester. Stir the reaction mixture at room temperature for eighteen hours and concentrate in vacuo. Place the residue on a column of silica gel (300 g, 60-200 mesh) and elute with hexane:ethyl acetate 4:1 to obtain 7-[N-benzyloxycarbonyl-(S)-alanyl]-1,4-dithia-7-azaspiro[4.4]nonane-8(S)-carboxylic acid, methyl ester, a yellow oil [α]D26 =-14.8° (ethanol).

Workup

  1. extractionextract with ethyl acetate
  2. dry with materialDry the organic layer over magnesium sulfate
  3. concentrationconcentrate in vacuo

Sources & evidence

ORD record
ord-5a6c40e53d50424aaccf3fcf8c67aea1
Source dataset
uspto-grants-1984_09
Patent number
US04470972

Reaction notes

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