Ethanethiol → Benzyl 6-benzyl-3-ethylthio-7-oxo-1-azabicyclo[3.2.0]heptane-2-carboxylate

HRID 67939Notes

Reaction equation

HRID 67939 reaction equation
[CH2:1]([CH:8]1[C:14](=[O:15])[N:13]2[CH:9]1[CH2:10][CH:11]=[C:12]2[C:16]([O:18][CH2:19][C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1)=[O:17])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[CH2:26]([SH:28])[CH3:27].C(=O)([O-])[O-].[K+].[K+]>CN(C)C=O>[CH2:1]([CH:8]1[C:14](=[O:15])[N:13]2[CH:9]1[CH2:10][CH:11]([S:28][CH2:26][CH3:27])[CH:12]2[C:16]([O:18][CH2:19][C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1)=[O:17])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 6343EthanethiolHCID 11430Potassium CarbonateHCID 14328938HCID 14328938, compound

Product 1

HCID 20526358Benzyl 6-benzyl-3-ethylthio-7-oxo-1-azabicyclo[3.2.0]heptane-2-carboxylate

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

Benzyl 6-benzyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate (138) (0.420 g) was dissolved in dry dimethylformamide (5 ml) and treated with ethanethiol (0.12 ml) and potassium carbonate (0.087 g). It was stirred at ambient temperature for 1 hour and the solvent was then distilled off under high vacuum. The residue was partitioned between ethyl acetate and brine, and the ethyl acetate solution was dried over sodium sulphate and concentrated. The residue was carefully chromatographed on a column of silica gel 60 (<230 mesh) eluting with ethyl acetate/60°-80° petroleum ether 3:7 to give three diastereoisomers of benzyl 6-benzyl-3-ethylthio-7-oxo-1-azabicyclo[3.2.0]heptane-2-carboxylate as gums. The first compound in increasing order of polarity was the 2α, 3α-isomer (139) (0.054 g); νmax (CHCl3) 2950, 1765 and 1745 sh; τ(CDCl3) 2.6-2.9 (10H, m, phenyls), 4.86(2H, s, OCH2), 5.59(1H, d J 5 Hz, C2-H), 6.1-6.5(2H, m, C3-H and C5-H), 6.6-7.2(3H, m, C6-H, C8-H2), 7.50(2H, q J7 Hz, SCH2), 7.55 (1H, dt J14 and 7 Hz, C4-H), 8.41(1H, dt J14 and 7 Hz, C4-H) and 8.84(3H, t J7 Hz, CH3); (M+ at m/e 395.1554. C23H25NO3S requires 395.1553). Next was the 2α, 3β-isomer (98 ) (0.260 g); νmax (CHCl3) 2960, 1765 and 1750 sh cm-1 ; τ(CDCl3) 2.6-2.9 (10H m, phenyls), 4.87 (2H, s, OCH2), 5.26(1H, d, J7 Hz, C2-H), 6.10(1H, td, J51/2& 21/2 Hz, C5-H), 6.52(1H, td J9 and 7 Hz, C3-H), 6.7-7.2(3H, m, C6-H, C8-H2), 7.47(2H, q, J7 Hz, SCH2), 7.89 (2H, dd J9 and 51/2 Hz, C4-H2) and 8.85(3H, t J7 Hz, CH3); (M+ at m/e 395.1553. C23H25NO3S requires 395.1553). Lastly was obtained the 2β, 3α-isomer (140) (0.112 g); νmax (CHCl3) 2960, 1770 and 1745 cm-1 ; τ(CDCl3) 2.6-2.9(10H, m, phenyls), 4.82(2H, s, OCH2), 5.94(1H, d J8 Hz, C2-H), 6.2-7.2(5H, m, C3-H, C5-H, C6-H and C8-H2), 7.51(2H, d J7 Hz, SCH2), 7.83(1H, dt J12 and 6 Hz, C4-H), 8.10(1H, td J12 and 9 Hz, C4-H) and 8.86(3H, t J7 Hz, CH3); (M+ at m/e 394.1560. C23H25NO3S requires 395.1553).

Workup

  1. distillationthe solvent was then distilled off under high vacuum
  2. customThe residue was partitioned between ethyl acetate and brine
  3. dry with materialthe ethyl acetate solution was dried over sodium sulphate
  4. concentrationconcentrated
  5. customThe residue was carefully chromatographed on a column of silica gel 60 (<230 mesh)
  6. washeluting with ethyl acetate/60°-80° petroleum ether 3:7

Sources & evidence

ORD record
ord-18f30b7ca0e648a9bbe735f0db003122
Source dataset
uspto-grants-1982_08
Patent number
US04347181

Reaction notes

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