Sulfuric Acid → HCID 10535400, compound

HRID 610610Notes

Reaction equation

HRID 610610 reaction equation
[CH2:1]([O:3][C:4]1[C:8]2[CH2:9][CH2:10][CH2:11][CH2:12][C:7]=2[O:6][N:5]=1)[CH3:2].[OH:13]S(O)(=O)=O.[Cr](O[Cr]([O-])(=O)=O)([O-])(=O)=O.[Na+].[Na+].[OH-].[Na+]>C(O)(=O)C.C(OCC)C>[CH2:1]([O:3][C:4]1[C:8]2[C:9](=[O:13])[CH2:10][CH2:11][CH2:12][C:7]=2[O:6][N:5]=1)[CH3:2]

Participants

7

Reactant 4

HCID 1118Sulfuric AcidHCID 14798Sodium HydroxideHCID 25408Sodium DichromateHCID 10654638HCID 10654638, compound

Product 1

HCID 10535400HCID 10535400, compound

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolvent2×HCID 3283Diethyl EtherSolvent

Conditions

Temperature
27.5 °C

Procedure

To a solution of 3-ethoxy-4,5,6,7-tetrahydro-1,2-benzisoxazole 1a (35 g) in glacial acetic acid (500 mL) at 10° C. was added concentrated H2SO4 (29 mL). A solution of sodium dichromate (71 g) in glacial acetic acid (300 mL) kept at 40-45° C. was added dropwise during one hour at 20-25° C. The mixture was stirred for another 3 hours at 25-30° C. The reaction mixture was poured onto ice and diethyl ether (3 L). pH was adjusted to >10 by addition of concentrated aqueous NaOH. The organic phase was separated and worked up. The remaining crude title compound was purified by column chromatography on silica gel (eluted with ethyl acetate/heptane 1:1). Pure 3-ethoxy-4,5,6,7-tetrahydro-1,2-benzisoxazol-4-one was washed with diisopropyl ether and dried. Yield 27 g. Mp 98-99° C.

Workup

  1. customkept at 40-45° C.
  2. additionwas added dropwise during one hour at 20-25° C
  3. customThe organic phase was separated
  4. customThe remaining crude title compound was purified by column chromatography on silica gel (eluted with ethyl acetate/heptane 1:1)
  5. washPure 3-ethoxy-4,5,6,7-tetrahydro-1,2-benzisoxazol-4-one was washed with diisopropyl ether
  6. customdried

Sources & evidence

ORD record
ord-c5a7805b62124235a660c5255b4a9793
Source dataset
uspto-grants-1999_12
Patent number
US05998613

Reaction notes

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