Phosphorus oxychloride → 7-Chloro-2-(trimethylsilyl)furo[3,2-b]pyridine

HRID 1470336Notes

Reaction equation

HRID 1470336 reaction equation
[CH3:1][Si:2]([CH3:14])([CH3:13])[C:3]1[O:11][C:10]2[C:5](=[N+:6]([O-])[CH:7]=[CH:8][CH:9]=2)[CH:4]=1.O=P(Cl)(Cl)[Cl:17]>>[Cl:17][C:9]1[CH:8]=[CH:7][N:6]=[C:5]2[CH:4]=[C:3]([Si:2]([CH3:14])([CH3:13])[CH3:1])[O:11][C:10]=12

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 667793722-(Trimethylsilyl)furo[3,2-B]pyridine 4-oxide

Product 1

HCID 594273397-Chloro-2-(trimethylsilyl)furo[3,2-b]pyridine

Procedure

A solution of 2-(trimethylsilyl)furo(3,2-b)pyridine N-oxide (32 g, 0.153 mol) in POCl3 (150 ml) is heated to 100° C. for 2 h in a sealed pressure tube. The reaction mixture is cooled to RT, concentrated under vacuum, the residue is dissolved in DCM (500 ml), washed with saturated sodium bicarbonate (100 ml×2), water (50 ml×2) and with sat brine (50 ml), dried over sodium sulphate and concentrated under vacuum. The crude material is purified by column chromatography by using petrolether/ethyl acetate (9:1) as an eluent to afford the title compound as (18 g, 52%) light brown oil. TLC: hexane/ethyl acetate: (8/2): Rf=0.80; 1H NMR (DMSO-d6, 400 MHz) δ [ppm] 8.461-8.448 (1H, d, J=5.2 Hz), 7.502-7.477 (2H, m), 0.372-0.355 (9H, s); LCMS (method C): 3.29 min (purity 95.8%), M+H+ 226.0.

Workup

  1. concentrationconcentrated under vacuum
  2. dissolutionthe residue is dissolved in DCM (500 ml)
  3. washwashed with saturated sodium bicarbonate (100 ml×2), water (50 ml×2) and with sat brine (50 ml)
  4. dry with materialdried over sodium sulphate
  5. concentrationconcentrated under vacuum
  6. customThe crude material is purified by column chromatography

Sources & evidence

ORD record
ord-5bb115631a574078a68f9a39507c5726
Source dataset
uspto-grants-2015_04
Patent number
US09006440B2

Reaction notes

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