Sodium cyanoborohydride → N-Methyl-N-((1-methyl-3-nitro-1H-pyrazol-5-yl)methyl)oxetan-3-amine

HRID 1412041Notes

Reaction equation

[CH3:1][NH:2][CH2:3][C:4]1[N:8]([CH3:9])[N:7]=[C:6]([N+:10]([O-:12])=[O:11])[CH:5]=1.[O:13]1[CH2:16][C:15](=O)[CH2:14]1.[BH3-]C#N.[Na+]>CO.[Cl-].[Cl-].[Zn+2]>[CH3:1][N:2]([CH2:3][C:4]1[N:8]([CH3:9])[N:7]=[C:6]([N+:10]([O-:12])=[O:11])[CH:5]=1)[CH:15]1[CH2:16][O:13][CH2:14]1

Participants

Conditions

Temperature: 50 °C

Procedure

To a mixture of 302a (170 mg, 1 mmol) in methanol (4 mL), ZnCl2 (1 mmol/L in diethyl ether) (2 mL, 2 mmol) and oxetan-3-one (150 mg, 2 mmol) were added at room temperature under nitrogen protection, followed by the addition of NaBH3CN (130 mg, 2 mmol). The reaction mixture was warmed to 50° C. and stirred for 3 h. The mixture was then cooled to room temperature and the solvent was removed. The residue was purified on flush column eluting with 50:1 methylene chloride/methanol to afford 302b as a yellow solid (180 mg, 80%, two steps). LCMS: (M+H)+ 227. 1H NMR (500 MHz, DMSO) δ 6.99 (s, 1H), 4.52 (t, J=6.5, 2H), 4.42 (t, J=6, 2H), 3.98 (s, 3H), 3.63 (m, 1H), 3.50 (s, 2H), 2.03 (s, 3H).

Workup

additionwere added at room temperature under nitrogen protection
temperatureThe mixture was then cooled to room temperature
customthe solvent was removed
customThe residue was purified
customon flush column
washeluting with 50:1 methylene chloride/methanol

Sources & evidence

ORD record: ord-60841fefd8874b1f8a615a0145495d41
Source dataset: uspto-grants-2014_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08921353B2

Reaction notes

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