Sodium Azide → N-(benzenesulfonyl)-trans-4-azidoproline, methyl ester

HRID 460275Notes

Reaction equation

HRID 460275 reaction equation
[C:1]1([S:7]([N:10]2[CH2:18][C@@H:17](OS(C)(=O)=O)[CH2:16][C@H:11]2[C:12]([O:14][CH3:15])=[O:13])(=[O:9])=[O:8])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[N-:24]=[N+:25]=[N-:26].[Na+]>CN(C=O)C>[C:1]1([S:7]([N:10]2[CH2:18][C@H:17]([N:24]=[N+:25]=[N-:26])[CH2:16][C@H:11]2[C:12]([O:14][CH3:15])=[O:13])(=[O:9])=[O:8])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1

Participants

4

Reactant 2

HCID 33557Sodium AzideHCID 58825077N-(benzenesulfonyl)-cis-4-(methanesulfonyloxy)-proline, methyl ester

Product 1

HCID 58825074N-(benzenesulfonyl)-trans-4-azidoproline, methyl esterYield 85%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
-60 °C

Procedure

In a 50 mL flask were combined 16 (0.60 g, 1.65 mmol) and 1.07 g (16.5 mmol, 10 equiv.) of sodium azide (Aldrich) in 10 mL of anhydrous DMF. The colorless solution was heated at −60° C. under a CaCl2 drying tube overnight, then allowed to cool and filtered. The flask and filter solids were washed with EtOAc, and the filtrate concentrated to dryness. The white residue was dissolved in EtOAc, washed twice with water, then brine, dried (MgSO4), filtered, and concentrated to give a pale yellow, waxy solid. This was recrystallized from EtOAc/hexanes to give 0.43 g (1.39 mmol, 85%) of 17 as fine white needles. 1H-NMR (400 MHz, CDCl3, δ ppm) 7.86 (dt, J=1 Hz, 8 Hz, 2H), 7.61 (tt, J=1 Hz, 8 Hz, 1H), 7.54 (tt, J=1Hz, 8 Hz, 2 H), 4.29 (t, J=8 Hz, 1H), 4.18 (m, 1H), 3.74 (s, 3H), 3.69 (q, J=5 Hz, 1H), 3.41 (dd, J=3 Hz, 11 Hz, 1H), 2.17 (m, 2H); 13C-NMR (400 MHz, CDCl3, 6 ppm) 179.46, 145.01, 140.85, 136.81, 135.14, 67.03, 66.97, 60.71, 60.37, 44.03; m/z: 311 (M+1)+. The trans-stereochemistry was confirmed by X-ray crystal structure.

Workup

  1. customIn a 50 mL flask were combined
  2. temperatureto cool
  3. filtrationfiltered
  4. filtrationThe flask and filter solids
  5. washwere washed with EtOAc
  6. concentrationthe filtrate concentrated to dryness
  7. dissolutionThe white residue was dissolved in EtOAc
  8. washwashed twice with water
  9. dry with materialbrine, dried (MgSO4)
  10. filtrationfiltered
  11. concentrationconcentrated
  12. customto give a pale yellow, waxy solid
  13. customThis was recrystallized from EtOAc/hexanes

Sources & evidence

ORD record
ord-fc958c2b9862454088e971c9605ad2f2
Source dataset
uspto-grants-2007_03
Patent number
US07196112B2

Reaction notes

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