Nitric Acid → 3,3-dimethyl-6-nitrobenzo[c][1,2]oxaborol-1(3H)-ol

HRID 60551Notes

Reaction equation

HRID 60551 reaction equation
[N+:1]([O-:4])(O)=[O:2].[CH3:5][C:6]1([CH3:16])[O:10][B:9]([OH:11])[C:8]2[CH:12]=[CH:13][CH:14]=[CH:15][C:7]1=2>[N+](C1C=CC=CC=1)([O-])=O>[CH3:5][C:6]1([CH3:16])[O:10][B:9]([OH:11])[C:8]2[CH:12]=[C:13]([N+:1]([O-:4])=[O:2])[CH:14]=[CH:15][C:7]1=2

Participants

4

Reactant 2

HCID 944Nitric AcidHCID 442289743,3-Dimethyl-1,3-dihydro-2,1-benzoxaborol-1-ol

Product 1

HCID 583730633,3-dimethyl-6-nitrobenzo[c][1,2]oxaborol-1(3H)-olYield 51.8%

Reagents, catalysts & solvents 1

HCID 7416NitrobenzeneSolvent

Conditions

Temperature
-42.5 °C

Procedure

To 106 mL fuming HNO3 at −45° C. was slowly added a solution of 3,3-dimethyl-3H-benzo[c][1,2]oxaborol-1-ol (16.9 g, 104.3 mmol) in 10.5 mL nitrobenzene via a syringe while maintaining the reaction temperature between −40 to −45° C. Once the addition was complete the resulting solution was allowed to stir at −45° C. for an additional 45 min before poured into crushed ice. The ice mixture was allowed to melt and the aqueous solution was extracted with DCM (3×). The combined DCM extracts were dried over Na2SO4 then evaporated. The crude oil remaining was mixed with one liter 1:1 DCM/heptanes. The volume of the solution was reduced under reduced pressure by half and the resulting solution was allowed to stand overnight in a −20° C. freezer. The precipitate formed was filtered out, washed with heptanes and vacuum dried to give the titled compound as a white solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 1.46 (s, 6 H) 7.69 (d, J=8.4 Hz, 1 H) 8.28 (dd, J=8.4, 2.3 Hz, 1 H) 8.48 (d, J=2.2 Hz, 1 H) 9.41 (br. s., 1 H). Amount obtained: 11.2 g (51.8% yield).

Workup

  1. additionOnce the addition
  2. additionbefore poured
  3. custominto crushed ice
  4. extractionthe aqueous solution was extracted with DCM (3×)
  5. dry with materialThe combined DCM extracts were dried over Na2SO4
  6. customthen evaporated
  7. additionThe crude oil remaining was mixed with one liter 1:1 DCM/heptanes
  8. waitto stand overnight in a −20° C.
  9. customThe precipitate formed
  10. filtrationwas filtered out
  11. washwashed with heptanes and vacuum
  12. customdried

Sources & evidence

ORD record
ord-eba6676e3f9f40e1b4f29b5c639e225a
Source dataset
uspto-grants-2016_09
Patent number
US09440994B2

Reaction notes

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