Phosphorus sulfide (P2S5) → methyl 3,4-dihydro-2-isopropyl-3-thioxo-2H-1,4-benzoxazine-4-acetate

HRID 622365Notes

Reaction equation

HRID 622365 reaction equation
[CH:1]([CH:4]1[C:9](=O)[N:8]([CH2:11][C:12]([O:14][CH3:15])=[O:13])[C:7]2[CH:16]=[CH:17][CH:18]=[CH:19][C:6]=2[O:5]1)([CH3:3])[CH3:2].P12(SP3(SP(SP(S3)(S1)=S)(=S)S2)=S)=[S:21]>C1(C)C=CC=CC=1>[CH:1]([CH:4]1[C:9](=[S:21])[N:8]([CH2:11][C:12]([O:14][CH3:15])=[O:13])[C:7]2[CH:16]=[CH:17][CH:18]=[CH:19][C:6]=2[O:5]1)([CH3:3])[CH3:2]

Participants

4

Reactant 2

HCID 14817Phosphorus sulfide (P2S5)HCID 14234696methyl 3,4-dihydro-2-isopropyl-3-oxo-2H-1,4-benzoxazine-4-acetate

Product 1

HCID 14234697methyl 3,4-dihydro-2-isopropyl-3-thioxo-2H-1,4-benzoxazine-4-acetate

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A mixture of methyl 3,4-dihydro-2-isopropyl-3-oxo-2H-1,4-benzoxazine-4-acetate (26.0 g), phosphorus pentasulfide (44.4 g) and toluene (250 ml) was refluxed for 3 hours with heating. After cooling the insoluble matter was removed by filtration, and the solvent was evaporated off. To the residue, isopropyl ether (200 ml) was added and the insoluble matter was removed by filtration. The solvent was evaporated off, and hexane was added to the residue, to give crystals of methyl 3,4-dihydro-2-isopropyl-3-thioxo-2H-1,4-benzoxazine-4-acetate. Yield was 22.5 g (80.6%). Recrystallization from isopropyl alcohol gave yellow prisms (mp 60°-61° C.).

Workup

  1. temperaturewas refluxed for 3 hours
  2. temperaturewith heating
  3. temperatureAfter cooling the insoluble matter
  4. customwas removed by filtration
  5. customthe solvent was evaporated off
  6. additionTo the residue, isopropyl ether (200 ml) was added
  7. customthe insoluble matter was removed by filtration
  8. customThe solvent was evaporated off
  9. additionhexane was added to the residue

Sources & evidence

ORD record
ord-d8c49f9c43b94e2780ab5045267c9c1f
Source dataset
uspto-grants-1988_09
Patent number
US04771050

Reaction notes

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