Potassium Carbonate → 5-nitro-1-(pyridin-2-ylmethyl)-1H-indazole

HRID 1162208Notes

Reaction equation

[N+:1]([C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[NH:9][N:8]=[CH:7]2)([O-:3])=[O:2].Cl.[N:14]1[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=1[CH2:20]Cl.C(=O)([O-])[O-].[K+].[K+]>CN(C=O)C.O>[N+:1]([C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[N:9]([CH2:20][C:15]1[CH:16]=[CH:17][CH:18]=[CH:19][N:14]=1)[N:8]=[CH:7]2)([O-:3])=[O:2]

Participants

Conditions

Temperature: 75 °C

Procedure

A mixture of 5-nitroindazole (40.75 g, 250 mmol), picolyl chloride hydrochloride (45.1 g, 275 mmol) and potassium carbonate (72.4 g, 525 mmol) in DMF (400 ml) was heated at 75° C. for 3 hours. Additional picolyl chloride hydrochloride (4.1 g, 25 mmol) and potassium carbonate (3.45 g, 25 mmol) were added and the mixture was heated at 75° C. for 2 additional hours. After cooling, the mixture was diluted with water (800 ml). The precipitate was filtered, washed with water and dried. The resulting solid was purified by chromatography on silica gel (eluant: 50% ethyl acetate in petroleum ether) to give 5-nitro-1-(pyridin-2-ylmethyl)-1H-indazole as a solid (34.5 g, 55%); NMR Spectrum (CDCl3) 5.77 (s, 2H), 7.03 (d, 1H), 7.23 (m, 1H), 7.55 (d, 1H), 7.63 (m, 1H), 8.27-8.23 (m, 2H), 8.58 (m, 1H), 8.74 (d, 1H); Mass spectrum MH+ 255.

Workup

temperaturethe mixture was heated at 75° C. for 2 additional hours
temperatureAfter cooling
filtrationThe precipitate was filtered
washwashed with water
customdried
customThe resulting solid was purified by chromatography on silica gel (eluant: 50% ethyl acetate in petroleum ether)

Sources & evidence

ORD record: ord-95e5fe9f4ba24f9cb02c2a372a67d2d6
Source dataset: uspto-grants-2010_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07820683B2

Reaction notes

Loading…