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 2226402Notes

Reaction equation

HRID 2226402 reaction equation
Br.[S:2]1[C:6]2([CH2:10][C@@H:9]([C:11]([O:13][CH3:14])=[O:12])[NH:8][CH2:7]2)[S:5][CH2:4][CH2:3]1>[OH-].[Na+]>[S:2]1[C:6]2([CH2:10][C@@H:9]([C:11]([O:13][CH3:14])=[O:12])[NH:8][CH2:7]2)[S:5][CH2:4][CH2:3]1

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 0.1N 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-benzyloxy-carbonyl-(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-3199e928d7c548c591f318bec0626d04
Source dataset
uspto-grants-1994_09
Patent number
US05348944

Reaction notes

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