Sulfuric Acid → 7-Isopropyl-4-methyl-benzooxazol-6-ol

HRID 2266186Notes

Reaction equation

HRID 2266186 reaction equation
[NH2:1][C:2]1[C:7]([CH3:8])=[CH:6][C:5]([OH:9])=[C:4]([CH:10]([CH3:12])[CH3:11])[C:3]=1[OH:13].O[C:15]1C=C(C(C)C)C=C(O)C=1C.C1(C)CC(=O)C(C(C)C)C(=O)C1.C(OC(OCC)OCC)C.OS(O)(=O)=O>CCO.[Cl-].[Ti+4].[Cl-].[Cl-].[Cl-]>[CH:10]([C:4]1[C:3]2[O:13][CH:15]=[N:1][C:2]=2[C:7]([CH3:8])=[CH:6][C:5]=1[OH:9])([CH3:11])[CH3:12]

Participants

8

Reactant 5

HCID 1118Sulfuric AcidHCID 31214Ethyl orthoformateHCID 119881382-Isopropyl-5-methylcyclohexane-1,3-dioneHCID 23345336CymorcinHCID 595987544-Amino-2-isopropyl-5-methyl-benzene-1,3-diol

Product 1

HCID 595986577-Isopropyl-4-methyl-benzooxazol-6-ol

Reagents, catalysts & solvents 2

HCID 160960Diamminetetrachlorotitanate(IV)CatalystHCID 702EthanolSolvent2×

Conditions

Temperature
0 °C

Procedure

To a flask charged with 4-amino-2-isopropyl-5-methyl-benzene-1,3-diol (450 mg, 2.5 mmol) (Treibs and Albrecht, “The dihydroxycymenes. IV. Isocymorcin (3,5-dihydroxycymene) from 3,5-menthanedione by dehydrogenation and total synthesis,” Journal fuer Praktische Chemie (1961), 13, 291-305), purged with argon, and cooled to 0° C. was sequentially added triethylorthoformate (0.7 mL, 4.2 mmol), EtOH (4 mL), and a 10% v/v solution of H2SO4 in EtOH (40 μL). The reaction was allowed to warm to room temperature slowly, stirred overnight, quenched with saturated NaHCO3, and concentrated. The residue was partitioned between water and methylene chloride. The combined organic phases were dried with Na2SO4 and concentrated to provide 510 mg of 7-isopropyl-4-methyl-benzooxazol-6-ol.

Workup

  1. custompurged with argon
  2. temperatureto warm to room temperature slowly
  3. customquenched with saturated NaHCO3
  4. concentrationconcentrated
  5. customThe residue was partitioned between water and methylene chloride
  6. dry with materialThe combined organic phases were dried with Na2SO4
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-536a95d0c42942c4a8131ce0f53912cd
Source dataset
uspto-grants-2010_12
Patent number
US07858632B2

Reaction notes

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