Hydrochloric Acid → 5-Amino-3-methylbenzo[d]isoxazole

HRID 873846Notes

Reaction equation

HRID 873846 reaction equation
[CH3:1][C:2]1[C:6]2[CH:7]=[C:8]([N+:11]([O-])=O)[CH:9]=[CH:10][C:5]=2[O:4][N:3]=1.O.O.[Sn](Cl)Cl.Cl>CC(O)=O>[CH3:1][C:2]1[C:6]2[CH:7]=[C:8]([NH2:11])[CH:9]=[CH:10][C:5]=2[O:4][N:3]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 61436Stannous chloride dihydrateHCID 124113183-Methyl-5-nitro-1,2-benzoxazole

Product 1

HCID 213453975-Amino-3-methylbenzo[d]isoxazoleYield 31%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
100 °C

Procedure

To a stirred solution of 3-methyl-5-nitrobenzo[d]isoxazole (Step 33.2) (1.8 g, 10.10 mmol) in AcOH (40 mL) was added a solution of tin(II) chloride dihydrate (6.84 g, 30.3 mmol) in HCl (15 mL, 494 mmol). The reaction mixture was stirred for 1 hr at 100° C., quenched with a saturated aq. NaHCO3 solution, diluted with water, and extracted with CH2Cl2. The combined organic layers were washed once with a saturated aq. NH4Cl solution, dried over Na2SO4 and evaporated. The crude material was purified by silica gel column chromatography (hexane/EtOAc 20-50) to afford the title product (458 mg, 3.09 mmol, 31% yield) as a pink solid. tR: 0.50 min (LC-MS 2); ESI-MS: 149 [M+H]+ (LC-MS 2); Rf=0.45 (hexane/EtOAc 1:1).

Workup

  1. customquenched with a saturated aq. NaHCO3 solution
  2. additiondiluted with water
  3. extractionextracted with CH2Cl2
  4. washThe combined organic layers were washed once with a saturated aq. NH4Cl solution
  5. dry with materialdried over Na2SO4
  6. customevaporated
  7. customThe crude material was purified by silica gel column chromatography (hexane/EtOAc 20-50)

Sources & evidence

ORD record
ord-01eedb37109740a4a4199c47ac47b68f
Source dataset
uspto-grants-2015_03
Patent number
US08975417B2

Reaction notes

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