Nitric Acid → 3'-isopropyl-7-nitro-3,4-dihydro-2H-1,5-benzodioxepin-3-spiro-5'-oxazolidin-2'-one

HRID 267797Notes

Reaction equation

HRID 267797 reaction equation
[CH:1]([N:4]1[CH2:8][C:7]2([CH2:14][O:13][C:12]3[CH:15]=[CH:16][CH:17]=[CH:18][C:11]=3[O:10][CH2:9]2)[O:6][C:5]1=[O:19])([CH3:3])[CH3:2].[N+:20]([O-])([OH:22])=[O:21].S(=O)(=O)(O)O>C(O)(=O)C>[CH:1]([N:4]1[CH2:8][C:7]2([CH2:9][O:10][C:11]3[CH:18]=[CH:17][C:16]([N+:20]([O-:22])=[O:21])=[CH:15][C:12]=3[O:13][CH2:14]2)[O:6][C:5]1=[O:19])([CH3:3])[CH3:2]

Participants

5

Reactant 3

HCID 944Nitric Acid2×HCID 1118Sulfuric Acid2×HCID 155573263'-isopropyl-3,4-dihydro-2H-1,5-benzodioxepin-3-spiro-5'-oxazolidin-2'-one

Product 1

HCID 155573273'-isopropyl-7-nitro-3,4-dihydro-2H-1,5-benzodioxepin-3-spiro-5'-oxazolidin-2'-oneYield 53.8%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

A solution of 3'-isopropyl-3,4-dihydro-2H-1,5-benzodioxepin-3-spiro-5'-oxazolidin-2'-one (24.8 g.; 94.2 mmole) in acetic acid (100 ml.) is cooled in an ice bath to the point at which freezing begins. A mixture of 90% nitric acid and concentrated sulfuric acid (54 mls., containing 1.2 ml. of nitric acid (d 1.5) to each 10 ml. of sulfuric acid, (ca. 124 mmole) is added dropwise with stirring over a period of 20 minutes, the cooling bath then is removed and stirring continued for 2 hours. A slight rise in the temperature of the reaction mixture will be noticed (to 34° C.) and the color darkens slightly. The nitration can be followed by thin layer chromatography (TLC) on silica gel using multiple development with 1:1 carbon tetrachloride/chloroform. The reaction mixture is poured into water (400 ml.) and the crude product extracted with methylene chloride (3 × 100 ml.). After washing the extract successively with water (100 ml.), 10% sodium carbonate (75 ml.) and again with water (100 ml.), it is dried over magnesium sulphate and evaporated to a syrup. The syrup is crystallized by boiling it with ethanol (50 ml.) yielding 15.58 g. (53.8%) of 3'-isopropyl-7-nitro-3,4-dihydro-2H-1,5-benzodioxepin-3-spiro-5'-oxazolidin-2'-one, m.p. 140°-144° C. and a second crop is obtained by concentrating the mother liquor to ca. 25 ml. to give an additional 3.44 g. (11.8%) of compound, m.p. 130°-140° C.

Workup

  1. addition, containing 1.2 ml
  2. customthe cooling bath then is removed
  3. stirringstirring
  4. waitcontinued for 2 hours
  5. custom(to 34° C.)
  6. additionThe reaction mixture is poured into water (400 ml.)
  7. extractionthe crude product extracted with methylene chloride (3 × 100 ml.)
  8. washAfter washing the
  9. extractionextract successively with water (100 ml.), 10% sodium carbonate (75 ml.) and again with water (100 ml.), it
  10. dry with materialis dried over magnesium sulphate
  11. customevaporated to a syrup
  12. customThe syrup is crystallized
  13. customyielding 15.58 g

Sources & evidence

ORD record
ord-3e6236a1d94946c3b089c4c9862953e1
Source dataset
uspto-grants-1976_03
Patent number
US03944560

Reaction notes

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