Pyridine → HCID 22846532, compound

HRID 2255024Notes

Reaction equation

HRID 2255024 reaction equation
[Si:1]([O:18][CH2:19][C@@H:20](O)[C:21]#[CH:22])([C:14]([CH3:17])([CH3:16])[CH3:15])([C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.N1C=CC=CC=1.C(Br)(Br)(Br)[Br:50]>C1COCC1>[Br:50][C@H:20]([C:21]#[CH:22])[CH2:19][O:18][Si:1]([C:14]([CH3:17])([CH3:16])[CH3:15])([C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

6

Reactant 4

HCID 1049PyridineHCID 11205Carbon tetrabromideHCID 11776TriphenylphosphineHCID 14778754HCID 14778754, compound

Product 1

HCID 22846532HCID 22846532, compoundYield 97%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

A flask was charged with (S)-1-[(tert-Butyldiphenylsilyl)oxy]-3-butyn-2-ol (1) (1.30 g, 4 mmol), triphenylphosphine (2.52 g, 9.60 mmol), THF (30 mL), pyridine (360 mg, 4.56 mmol). To this mixture was added carbon tetrabromide (1.53 g, 4.60 mmol) in THF (10 ml) over a 5 minute period. The resulting reaction mixture was stirred for 45 minutes. Hexanes (50 mL) was added, and the mixture was filtered and concentrated in vacuo. The residue was taken up into hexanes (50 mL), washed with 1 M HCl (40 mL), saturated NaCl (40 mL). The organic extracts were dried (MgSO4) and concentrated by rotary evaporation to yield a yellow oil. Purification by flash silica gel chromatography (98:02 hexane/EtOAc) afforded (R)-2-bromo-1-[tert-butyldiphenylsilyloxy]-3-butyne (4) (1.50 g, 97%) as a colorless oil (Note: this material is unstable and should be used immediately): Rf 0.74 (90:10 hexane/EtOAc); IR (neat) 3308, 1437, 1112, 701 cm-1 ; 1H NMR (CDCl3) δ 7.70 (m, 4 H), 7.42 (m, 6 H), 4.46 (dt, J1 =6.66 Hz, J2 =2.36 Hz, 1 H), 3.91 (ddd, J1 =10.7 Hz, J2 =6.32, Hz, J3 =3.78 Hz, 2H), 2.59 (d, J=2.4 Hz, 2 H), 1.08 (m, 9H); 13C NMR (CDCl3); δ 135.8, 132.8, 129.6, 127.6, 80.3, 75.6, 67.5, 36.2, 26.8, 19.3. ##STR19##

Workup

  1. customThe resulting reaction mixture
  2. filtrationthe mixture was filtered
  3. concentrationconcentrated in vacuo
  4. washwashed with 1 M HCl (40 mL), saturated NaCl (40 mL)
  5. dry with materialThe organic extracts were dried (MgSO4)
  6. concentrationconcentrated by rotary evaporation
  7. customto yield a yellow oil
  8. customPurification by flash silica gel chromatography (98:02 hexane/EtOAc)

Sources & evidence

ORD record
ord-b4918d120a7c4a0ca1c820dd4a5373d5
Source dataset
uspto-grants-1993_08
Patent number
US05238832

Reaction notes

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