Boron trifluoride → HCID 23568484, compound

HRID 1823197Notes

Reaction equation

HRID 1823197 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH:17](OC)[CH2:16][CH2:15][C@H:9]1[C:10]([O:12][CH2:13][CH3:14])=[O:11])=[O:7])([CH3:4])([CH3:3])[CH3:2].C[Si]([C:24]#[N:25])(C)C.B(F)(F)F>C(Cl)Cl>[C:1]([O:5][C:6]([N:8]1[CH:17]([C:24]#[N:25])[CH2:16][CH2:15][C@H:9]1[C:10]([O:12][CH2:13][CH3:14])=[O:11])=[O:7])([CH3:2])([CH3:3])[CH3:4]

Participants

5

Reactant 3

HCID 6356Boron trifluorideHCID 82115Trimethylsilyl cyanideHCID 10445972Boc-5-methoxy-L-proline ethyl ester

Product 1

HCID 23568484HCID 23568484, compound

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of ethyl(2S)-N-tert-butoxycarbonyl-5-methoxyprolinate (4.10 g, 15.81 mmol) in CH2Cl2 (40 mL) at −50° C. was added trimethylsilyl cyanide (6.3 mL, 47.4 mmol) and BF3 etherate (5.60 mL, 47.4 mmol). The mixture was stirred from −50° C. to −30° C. for 2.0 h before it was quenched with saturated NaHCO3. The organic layer was separated and the aqueous phase was extracted with CH2Cl2. The combined organic layers were washed with brine and dried over MgSO4. Filtration, evaporation of solvent and flash column chromatography (hexane/ethyl acetate, 3:1) gave separated cis and tran isomers (2.20 g). 1HNMR (300 MHz, CDCl3) δ isomer 1: 4.68 (dd, J=4.0, 2.0 Hz) and 4.55 (t, J=5.4 Hz) for 1H, 4.40 (t, J=7.7 Hz) and 4.26 (t, J=6.9 Hz) for 1H, 3.79 (s, 3H), 2.42–1.98 (m, 4H), 1.52 (s) and 1.44 (s) for 9 H; isomer 2: 4.78 (dd, J=8.8, 1.5 Hz) and 4.67 (d, J=8.0 Hz) for 1H, 4.45 (d, J=8.8 Hz) and 4.34 (d, J=8.0 Hz) for 1H, 3.75 (s) and 3.73 (s) for 3H, 2.56–2.12 (m, 4H), 1.52 (s) and 1.43 (s) for 9H; CIMS 255 (M+H).

Workup

  1. customwas quenched with saturated NaHCO3
  2. customThe organic layer was separated
  3. extractionthe aqueous phase was extracted with CH2Cl2
  4. washThe combined organic layers were washed with brine
  5. dry with materialdried over MgSO4
  6. filtrationFiltration, evaporation of solvent and flash column chromatography (hexane/ethyl acetate, 3:1)
  7. customgave
  8. customseparated cis and tran isomers (2.20 g)

Sources & evidence

ORD record
ord-a77e1efa239b4211a23434381c5d342f
Source dataset
uspto-grants-2006_05
Patent number
US07037911B2

Reaction notes

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