p-Toluenesulfonic acid monohydrate → 4-(4-bromo-2-methylbenzylidene)-1-methyl-3-(pyridin-2-yl)-1H-pyrazol-5(4H)-imine

HRID 1748759Notes

Reaction equation

[CH3:1][N:2]1[C:6]([NH2:7])=[CH:5][C:4]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][N:9]=2)=[N:3]1.[Br:14][C:15]1[CH:22]=[CH:21][C:18]([CH:19]=O)=[C:17]([CH3:23])[CH:16]=1.O.CC1C=CC(S(O)(=O)=O)=CC=1>CC#N>[Br:14][C:15]1[CH:22]=[CH:21][C:18]([CH:19]=[C:5]2[C:6](=[NH:7])[N:2]([CH3:1])[N:3]=[C:4]2[C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][N:9]=2)=[C:17]([CH3:23])[CH:16]=1

Participants

Conditions

Temperature: 45 °C

Procedure

A suspension of 1-methyl-3-(pyridin-2-yl)-1H-pyrazol-5-amine (4.50 g, 25.8 mmol, Example #2 step B), 4-bromo-2-methylbenzaldehyde (5.14 g, 25.8 mmol, Astatech) and 4-methylbenzenesulfonic acid hydrate (0.491 g, 2.58 mmol) in MeCN (36 ml) was warmed up to about 45° C. for about 15 min to give a solution then the reaction was allowed to cool to rt. The precipitate was filtered and washed with MeCN to give 4-(4-bromo-2-methylbenzylidene)-1-methyl-3-(pyridin-2-yl)-1H-pyrazol-5(4H)-imine (5.88 g, 16.55 mmol, 64%) as a beige solid: LC-MS (Table 1, Method g) Rt=2.55 min, m/z 355/357 (M+H)+; 1H-NMR (DMSO-d6, Bruker 400 MHz) δ 9.07 (s, 1H), 8.60-8.57 (m, 1H), 8.02-7.95 (m, 2H), 7.91-7.86 (m, 1H), 7.61-7.50 (m, 2H), 7.40-7.31 (m, 1H), 7.19 (s, 1H), 3.96 (s, 3H), 2.62 (s, 3H).

Workup

customto give a solution
temperatureto cool to rt
filtrationThe precipitate was filtered
washwashed with MeCN

Sources & evidence

ORD record: ord-9b3380162fcd4ea38777c746548d837e
Source dataset: uspto-grants-2015_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09150592B2

Reaction notes

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