Benzyl Bromide → 7-Nitro-4-benzyloxy-1,2-benzisothiazole

HRID 1449121Notes

Reaction equation

HRID 1449121 reaction equation
[N+:1]([C:4]1[C:12]2[S:11][N:10]=[CH:9][C:8]=2[C:7]([OH:13])=[CH:6][CH:5]=1)([O-:3])=[O:2].[CH2:14](Br)[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1.C(=O)([O-])[O-].[K+].[K+]>CC(C)=O>[N+:1]([C:4]1[C:12]2[S:11][N:10]=[CH:9][C:8]=2[C:7]([O:13][CH2:14][C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)=[CH:6][CH:5]=1)([O-:3])=[O:2]

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 11430Potassium CarbonateHCID 1357653737-Nitro-4-hydroxy-1,2-benzisothiazole

Product 1

HCID 203499427-Nitro-4-benzyloxy-1,2-benzisothiazoleYield 70%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

200 g of 7-nitro-4-hydroxy-1,2-benzisothiazole, 260 g of benzyl bromide and 210 g of potassium carbonate in 2.5 l of acetone are refluxed for 12 hours. The entire mixture is then concentrated to one liter under reduced pressure, the residue is poured into a threefold amount of water and the batch is repeatedly extracted with methylene chloride. The combined organic phases are dried over magnesium sulfate and freed from solvent under reduced pressure. The crude product is recrystallized from a mixture of methanol and tetrahydrofuran. 200 g (70% of theory) of 7-nitro-4-benzyloxy-1,2-benzisothiazole of melting point 158°-160° C. are obtained.

Workup

  1. concentrationThe entire mixture is then concentrated to one liter under reduced pressure
  2. additionthe residue is poured into a threefold amount of water
  3. extractionthe batch is repeatedly extracted with methylene chloride
  4. dry with materialThe combined organic phases are dried over magnesium sulfate
  5. customThe crude product is recrystallized from a mixture of methanol and tetrahydrofuran

Sources & evidence

ORD record
ord-f16d282acc1940e4a0198c707844a3f4
Source dataset
uspto-grants-1980_02
Patent number
US04189433

Reaction notes

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