Phosphorus pentachloride → Methyl 2-chloro-1,3-benzoxazole-5-carboxylate

HRID 36318Notes

Reaction equation

HRID 36318 reaction equation
[CH3:1][O:2][C:3]([C:5]1[CH:6]=[CH:7][C:8]2[O:12][C:11](=S)[NH:10][C:9]=2[CH:14]=1)=[O:4].P(Cl)(Cl)(Cl)(Cl)[Cl:16]>P(Cl)(Cl)(Cl)=O>[Cl:16][C:11]1[O:12][C:8]2[CH:7]=[CH:6][C:5]([C:3]([O:2][CH3:1])=[O:4])=[CH:14][C:9]=2[N:10]=1

Participants

4

Reactant 2

HCID 24819Phosphorus pentachlorideHCID 53069482-Mercapto-1,3-benzoxazole-5-carboxylic acid methyl ester

Product 1

HCID 10774871Methyl 2-chloro-1,3-benzoxazole-5-carboxylate

Reagents, catalysts & solvents 1

HCID 24813Phosphorus oxychlorideSolvent

Procedure

In a round bottom flask equipped with a magnetic stirrer, nitrogen inlet, reflux condenser and drying tube were placed 5-methoxycarbonylbenzoxazolthione (5.2 g, 0.025 mole), phosphorus pentachloride (5.2 g, 0,025 mole), and phosphorus oxychloride (40 mL). The reaction mixture was heated by an oil bath at 95°-100° C. for 4 hours. The reaction mixture was allowed to cool to room temperature and filtered. The filtrate was distilled with a short path distillation apparatus and the product was collected at 160°-163° C. at 29 mm Hg. The product solidified on standing to give a pale yellow solid, m.p. 104°-106° C. Anal Calcd. for C9H6ClNO3: C, 51.1; H, 2.9; N, 6.6; Cl, 16.8. Found: C, 50.7; H, 2.9; N, 6.6; Cl, 16.3

Workup

  1. customIn a round bottom flask equipped with a magnetic stirrer, nitrogen inlet
  2. temperaturereflux condenser
  3. customdrying tube
  4. temperatureThe reaction mixture was heated by an oil bath at 95°-100° C. for 4 hours
  5. filtrationfiltered
  6. distillationThe filtrate was distilled with a short path distillation apparatus
  7. customthe product was collected at 160°-163° C. at 29 mm Hg
  8. customto give a pale yellow solid, m.p. 104°-106° C

Sources & evidence

ORD record
ord-3f54f68e8e714d0894984831cb812050
Source dataset
uspto-grants-1995_05
Patent number
US05413905

Reaction notes

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