Triethylamine → 4(S)-(Methoxycarbonyl)-N-benzyl-1,3-oxazolidine-2-thione

HRID 1242275Notes

Reaction equation

HRID 1242275 reaction equation
[C:1](Cl)(Cl)=[S:2].[CH2:5]([NH:12][C@H:13]([C:16]([OH:18])=[O:17])[CH2:14][OH:15])[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1.[CH2:19](N(CC)CC)C.[K+].[Br-]>C1COCC1.C(Cl)Cl>[CH3:19][O:17][C:16]([C@@H:13]1[CH2:14][O:15][C:1](=[S:2])[N:12]1[CH2:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)=[O:18]

Participants

7

Reactant 4

HCID 8471TriethylamineHCID 10040ThiophosgeneHCID 253877Potassium BromideHCID 853606(2S)-2-(benzylamino)-3-hydroxypropanoic acid

Product 1

HCID 210625274(S)-(Methoxycarbonyl)-N-benzyl-1,3-oxazolidine-2-thione

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolventHCID 8028TetrahydrofuranSolvent2×

Procedure

Thiophosgene (23.8 g, 207 mmol) in dry THF (200 mL) was slowly added to a solution of N-benzyl-L-serine (43.4 g, 207 mmol), triethylamine (41.9 g, 414 mmol) in dry THF (600 mL) at 60° C. under nitrogen. The mixture was stirred for 3 hours, and was stirred at room temperature for 12 hours. Triethylamine hydrochloride was removed by filtration and the solvent was evaporated in vacuo. The residue was purified by silica gel column chromatography eluted with ethyl acetate/n-hexane (1/1=v/v). Recrystallization from a mixed solvent [THF/n-hexane (2/1=v/v)] gave BnSL (40.1 g, 77%) as a white powder. [α]D25=35.0° (c=0.1 g/dL, in CH2Cl2). m.p.=101.3–101.8° C. 1H NMR (CD2Cl2): δ=3.70 (s, 3H, —OCH3), 4.32–4.37 (m, 1H, —CH2—), 4.54–4.59 (3H, —CH<, —CH2—, and —CH2—C6H5), 5.31–5.42 (m, 1H, —CH2—C6H5), 7.33–7.38 (5H, —C6H5) ppm. 13C NMR (CD2Cl2): δ=51.47 (—CH2—C6H5), 53.06 (—OCH3), 59.90 (—CH<), 65.55 (—CH2—), 128.98, 129.04, 129.48, 135.09 (—C6H5), 169.55 (—COOCH3), 189.39 (—OCSNH—) ppm. IR (KBr): 1743 (—COOCH3), 1481 (C═S), 1450, 1357, 1304, 1211, 971, 701 cm−1. C12H13NO3S: Calcd. C 57.35, H 5.21, N 5.57, S 12.76; Found C 57.54; H 5.19; N 5.64, S 12.72.

Workup

  1. stirringwas stirred at room temperature for 12 hours
  2. customTriethylamine hydrochloride was removed by filtration
  3. customthe solvent was evaporated in vacuo
  4. customThe residue was purified by silica gel column chromatography
  5. washeluted with ethyl acetate/n-hexane (1/1=v/v)
  6. customRecrystallization from a mixed solvent [THF/n-hexane (2/1=v/v)]
  7. customgave BnSL (40.1 g, 77%) as a white powder

Sources & evidence

ORD record
ord-6e022f3ed0ff48f3b0d7d1036155916a
Source dataset
uspto-grants-2006_10
Patent number
US07115705B2

Reaction notes

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