Phosphorus oxychloride → 2-Benzyl-4-(2-chloro-4-pyridyl)thiazole

HRID 4355Notes

Reaction equation

HRID 4355 reaction equation
[C:1]1([CH2:7][C:8]2[S:9][CH:10]=[C:11]([C:13]3[CH:18]=[CH:17][N+:16]([O-])=[CH:15][CH:14]=3)[N:12]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.P(Cl)(Cl)([Cl:22])=O>>[CH2:7]([C:8]1[S:9][CH:10]=[C:11]([C:13]2[CH:18]=[CH:17][N:16]=[C:15]([Cl:22])[CH:14]=2)[N:12]=1)[C:1]1[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 142310544-[2-(Phenylmethyl)-4-thiazolyl]pyridine-1-oxide

Product 1

HCID 142310552-Benzyl-4-(2-chloro-4-pyridyl)thiazoleYield 31%

Procedure

A suspension of 4-[2-(phenylmethyl)-4-thiazolyl]pyridine-1-oxide (1.00 g, 0.0037 mol) in phosphorous oxychloride (10.0 g) was warmed on a steam bath overnight. After cooling the reaction mixture was concentrated and the residue treated with an excess of aqueous sodium bicarbonate. The tan precipitate was collected, taken up in methylene chloride (15 mL) and ether (75 mL), and filtered through celite. The filtrate was concentrated to a total volume of 10 mL and diluted with hexane (50 mL). The product which crystallized on standing was collected and dried to afford 2-benzyl-4-(2-chloro-4-pyridyl)thiazole (325 mg, 31%). mp. 104°-106° C.

Workup

  1. temperaturewas warmed on a steam bath overnight
  2. temperatureAfter cooling the reaction mixture
  3. concentrationwas concentrated
  4. additionthe residue treated with an excess of aqueous sodium bicarbonate
  5. customThe tan precipitate was collected
  6. filtrationether (75 mL), and filtered through celite
  7. concentrationThe filtrate was concentrated to a total volume of 10 mL
  8. additiondiluted with hexane (50 mL)
  9. customThe product which crystallized on standing
  10. customwas collected
  11. customdried

Sources & evidence

ORD record
ord-c9b3112c5ae24285a00f3026a4e0278d
Source dataset
uspto-grants-1988_02
Patent number
US04725606

Reaction notes

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