Isopropylethanediol → Dimethyl 1-(2-isopropoxyethyl)-4-nitro-1H-pyrazole-3,5-dicarboxylate

HRID 420482Notes

Reaction equation

[N+:1]([C:4]1[C:5]([C:13]([O:15][CH3:16])=[O:14])=[N:6][NH:7][C:8]=1[C:9]([O:11][CH3:12])=[O:10])([O-:3])=[O:2].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[CH:36]([O:39][CH2:40][CH2:41]O)([CH3:38])[CH3:37].N(C(OC(C)C)=O)=NC(OC(C)C)=O>O1CCCC1>[CH:36]([O:39][CH2:40][CH2:41][N:7]1[C:8]([C:9]([O:11][CH3:12])=[O:10])=[C:4]([N+:1]([O-:3])=[O:2])[C:5]([C:13]([O:15][CH3:16])=[O:14])=[N:6]1)([CH3:38])[CH3:37]

Participants

Conditions

Temperature: 0 °C

Procedure

Dimethyl 4-nitro-1H-pyrazole-3,5-dicarboxylate (11.4 g, 50 mmol) was dissolved in tetrahydrofuran (200 mL) and the solution treated with triphenylphosphine (14.4 g, 55 mmol) and 2-isopropoxyethanol (6.36 mL, 55 mmol). The mixture was cooled on an ice bath to 0° C. and diisopropyl azodicarboxylate (10.8 mL, 55 mmol) added dropwise over 10 minutes, keeping the temperature between 20° C. and 30° C. The reaction mixture was then stirred at room temperature for 30 minutes. The reaction mixture was concentrated in vacuo and the crude product azeotroped with dichloromethane to yield the title product. 1H NMR (CDCl3, 400 MHz) δ: 1.02 (d, 6H), 3.45 (m, 1H), 3.72 (t, 2H), 3.90 (s, 3H), 3.94 (s, 3H), 4.74 (t, 2H). MS ES+ m/z 216 [MH]+

Workup

customthe temperature between 20° C. and 30° C
concentrationThe reaction mixture was concentrated in vacuo
customthe crude product azeotroped with dichloromethane

Sources & evidence

ORD record: ord-1be403a3cf1a42468cf95cd10f3297c1
Source dataset: uspto-grants-2012_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08097621B2

Reaction notes

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