Lithium tri-s-butylborohydride → 2-Methyl-7-(2-methyl-4-nitro-pyrazol-3-yl)oxepan-4-ol

HRID 521832Notes

Reaction equation

HRID 521832 reaction equation
[CH3:1][CH:2]1[CH2:8][C:7](=[O:9])[CH2:6][CH2:5][CH:4]([C:10]2[N:11]([CH3:18])[N:12]=[CH:13][C:14]=2[N+:15]([O-:17])=[O:16])[O:3]1.CCC(C)[BH-](C(C)CC)C(C)CC.[Li+]>C1COCC1>[CH3:1][CH:2]1[CH2:8][CH:7]([OH:9])[CH2:6][CH2:5][CH:4]([C:10]2[N:11]([CH3:18])[N:12]=[CH:13][C:14]=2[N+:15]([O-:17])=[O:16])[O:3]1

Participants

4

Reactant 2

HCID 3611392Lithium tri-s-butylborohydrideHCID 867137742-Methyl-7-(2-methyl-4-nitro-pyrazol-3-yl)oxepan-4-one

Product 1

HCID 867137752-Methyl-7-(2-methyl-4-nitro-pyrazol-3-yl)oxepan-4-olYield 81.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 2-methyl-7-(2-methyl-4-nitro-pyrazol-3-yl)oxepan-4-one (65 mg, 0.26 mmol) in THF (1 mL) under nitrogen cooled to −78° C. was added dropwise a solution of L-selectride (1 M in THF, 0.28 mL, 0.28 mmol). After 1 hr the mixture was quenched with MeOH (1 mL) and warmed to room temperature. EtOAc (10 mL) and brine (10 mL) were added and the layers separated. The aqueous layer was extracted with EtOAc (3×10 mL) and the combined organic layers were washed with brine (10 mL), separated, dried over Na2SO4 and concentrated under reduced pressure. Purification via silica gel column chromatography (0-100% EtOAc/isohexane) gave 2-methyl-7-(2-methyl-4-nitro-pyrazol-3-yl)oxepan-4-ol as a colourless solid (54 mg, 81%). 1H NMR (400 MHz, CDCl3) δ 8.01 (2s, 1H), 5.63-5.59 and 5.56-5.50 (2m, 1H), 4.26-4.01 (m, 5H), 3.88-3.73 (m, 1H), 2.21-1.72 (m, 4H), 1.28-1.23 (m, 3H), 0.99-0.81 (m, 2H).

Workup

  1. customAfter 1 hr the mixture was quenched with MeOH (1 mL)
  2. additionEtOAc (10 mL) and brine (10 mL) were added
  3. customthe layers separated
  4. extractionThe aqueous layer was extracted with EtOAc (3×10 mL)
  5. washthe combined organic layers were washed with brine (10 mL)
  6. customseparated
  7. dry with materialdried over Na2SO4
  8. concentrationconcentrated under reduced pressure
  9. customPurification via silica gel column chromatography (0-100% EtOAc/isohexane)

Sources & evidence

ORD record
ord-6f4895b491e2463d821fe84cfba99a3a
Source dataset
uspto-grants-2016_05
Patent number
US09328106B2

Reaction notes

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