Acetic Acid → 3,8-Dimethyl-6-nitro-[1,2,4]triazolo[4,3-A]pyridine

HRID 873919Notes

Reaction equation

[CH3:1][C:2]1[C:3]([NH:11][NH:12][C:13](=O)[CH3:14])=[N:4][CH:5]=[C:6]([N+:8]([O-:10])=[O:9])[CH:7]=1.CC(O)=O>O1CCOCC1>[CH3:14][C:13]1[N:4]2[CH:5]=[C:6]([N+:8]([O-:10])=[O:9])[CH:7]=[C:2]([CH3:1])[C:3]2=[N:11][N:12]=1

Participants

Conditions

Temperature: 100 °C

Procedure

To a suspension of N′-(3-methyl-5-nitropyridin-2-yl)acetohydrazide (Step 67.2) (41.5 g, 198 mmol) in dioxane (180 mL) was added AcOH (35 mL) and the reaction mixture was stirred for 3 hr at 100° C. The reaction mixture was cooled RT and the crystallization was facilitated by the addition of Et2O (700 mL) over a period of 3 hr. After stirring the suspension for 3 hr at 0° C., the crystals were collected, washed with Et2O and dried to afford the title product (23.4 g, 119 mmol, 60% yield) as a light yellow solid. tR: 0.51 min (LC-MS 2); ESI-MS: 193 [M+H]+ (LC-MS 2); TLC (EtOAc/MeOH 9:1) Rf=0.35; 1H NMR (400 MHz, DMSO-d6) δ ppm 2.60 (s, 3H) 2.80 (s, 3H) 7.87 (d, J=1.9 Hz, 1H) 9.45 (d, J=1.8 Hz, 1H).

Workup

temperatureThe reaction mixture was cooled RT
customthe crystallization
additionwas facilitated by the addition of Et2O (700 mL) over a period of 3 hr
stirringAfter stirring the suspension for 3 hr at 0° C.
customthe crystals were collected
washwashed with Et2O
customdried

Sources & evidence

ORD record: ord-0dd9b03b07324f1cb8cd40272c31f1d7
Source dataset: uspto-grants-2015_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08975417B2

Reaction notes

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