Nitrogen → 1-[4-(2-Methyl-[1,3]dioxolan-2-yl)-butyl]-4-nitro-1H-pyrazole

HRID 2064931Notes

Reaction equation

N#N.[N+:3]([C:6]1[CH:7]=[N:8][NH:9][CH:10]=1)([O-:5])=[O:4].C([O-])([O-])=O.[Cs+].[Cs+].Br[CH2:18][CH2:19][CH2:20][CH2:21][C:22]1([CH3:27])[O:26][CH2:25][CH2:24][O:23]1>C(C#N)(C)=O.CC(=O)OCC.O>[CH3:27][C:22]1([CH2:21][CH2:20][CH2:19][CH2:18][N:8]2[CH:7]=[C:6]([N+:3]([O-:5])=[O:4])[CH:10]=[N:9]2)[O:26][CH2:25][CH2:24][O:23]1

Participants

Conditions

Temperature: 80 °C

Procedure

In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), a solution of 4-nitro-1H-pyrazole (2.10 g, 18.68 mmol) and Cs2CO3 (6.67 g, 20.46 mmol) in AcCN (18.9 mL) was treated with a solution of 2-(4-bromo-butyl)-2-methyl-[1,3]dioxolane (4.15 g, 18.60 mmol) in AcCN (18.9 mL). The reaction mixture was stirred at 80° C. for 2 h. Water (100 mL) was added followed by EA (100 mL). The aq. layer was extracted with EA (200 mL) and the combined org. extracts were dried over MgSO4, filtered, and the solvents were removed under reduced pressure. Purification of the residue by FC (50:50 hept-EA) gave the title compound. TLC: rf (50:50 hept-EA)=0.46. LC-MS-conditions 02: tR=0.89 min; [M+H]+=256.36. 1H NMR (400 MHz, CDCl3) δ 1.31 (s, 3H), 1.38-1.53 (m, 2H), 1.65-1.77 (m, 2H), 1.90-2.02 (m, 2H), 3.88-3.94 (m, 2H), 3.94-3.99 (m, 2H), 4.17 (t, J=7.0 Hz, 2H), 8.08 (s, 1H), 8.14 (s, 1H).

Workup

extractionThe aq. layer was extracted with EA (200 mL)
dry with materialextracts were dried over MgSO4
filtrationfiltered
customthe solvents were removed under reduced pressure
customPurification of the residue by FC (50:50 hept-EA)

Sources & evidence

ORD record: ord-267eeb96b66e4e3fa3f7270212cc7061
Source dataset: uspto-grants-2012_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08288419B2

Reaction notes

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