Hydrochloric Acid → (2-Isopropyl-3-thioxo-2,3-dihydrobenzo[1,4]oxazin-4-yl)acetic acid

HRID 622366Notes

Reaction equation

HRID 622366 reaction equation
[CH:1]([CH:4]1[C:9](=[S:10])[N:8]([CH2:11][C:12]([O:14]C)=[O:13])[C:7]2[CH:16]=[CH:17][CH:18]=[CH:19][C:6]=2[O:5]1)([CH3:3])[CH3:2].Cl>[OH-].[Na+].O>[CH:1]([CH:4]1[C:9](=[S:10])[N:8]([CH2:11][C:12]([OH:14])=[O:13])[C:7]2[CH:16]=[CH:17][CH:18]=[CH:19][C:6]=2[O:5]1)([CH3:3])[CH3:2]

Participants

5

Reactant 2

HCID 313Hydrochloric AcidHCID 14234697methyl 3,4-dihydro-2-isopropyl-3-thioxo-2H-1,4-benzoxazine-4-acetate

Product 1

HCID 14234698(2-Isopropyl-3-thioxo-2,3-dihydrobenzo[1,4]oxazin-4-yl)acetic acid

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 14798Sodium HydroxideSolvent

Procedure

To a solution of methyl 3,4-dihydro-2-isopropyl-3-thioxo-2H-1,4-benzoxazine-4-acetate (16.7 g) in methanol-dioxane (2:3, 150 ml), 2N NaOH (60 ml) was added dropwise in 10 minutes with stirring. After completion of the addition, stirring was continued for further 15 minutes, and the mixture was diluted with water, acidified with 2N HCl, and subjected to extraction with ethyl acetate. The extract was washed with water, and dried (MgSO4), from which the solvent was evaporated off. To the residue, hexane was added, to give crystals of 3,4-dihydro-2-isopropyl-3-thioxo-2H-1,4-benzoxazine-4-acetic acid. Yield was 12.6 g (79.2%). Recrystallization from isopropyl ether-hexane gave yellow prisms (mp 99°-100° C.). Yield was 11.2 g (70.6%).

Workup

  1. additionAfter completion of the addition
  2. stirringstirring
  3. extractionsubjected to extraction with ethyl acetate
  4. washThe extract was washed with water
  5. dry with materialdried (MgSO4)
  6. customfrom which the solvent was evaporated off
  7. additionTo the residue, hexane was added

Sources & evidence

ORD record
ord-7b32606755574883aa854782cec37e61
Source dataset
uspto-grants-1988_09
Patent number
US04771050

Reaction notes

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