Formaldehyde → HCID 22706827, compound

HRID 353008Notes

Reaction equation

[CH:1]([C:3]1[CH:19]=[CH:18][C:6]([CH2:7][N:8]2[C:12]3[CH:13]=[CH:14][CH:15]=[CH:16][C:11]=3[N:10]=[C:9]2[CH3:17])=[CH:5][CH:4]=1)=[CH2:2].[CH2:20]=[O:21]>N1C=CC=CC=1>[CH:1]([C:3]1[CH:19]=[CH:18][C:6]([CH2:7][N:8]2[C:12]3[CH:13]=[CH:14][CH:15]=[CH:16][C:11]=3[N:10]=[C:9]2[CH2:17][CH2:20][OH:21])=[CH:5][CH:4]=1)=[CH2:2]

Participants

Conditions

Temperature: 95 °C

Procedure

Next, 1-(4-vinylbenzyl)-2-(2-hydroxyethyl)benzimidazole was prepared. A mixture of 1-(4-vinylbenzyl)-2-methylbenzimidazole (20.0 g, 81 mmol), formaldehyde (320 mmol as 26.1 g of the 37% aqueous solution), and 25 g of pyridine were stirred magnetically and heated to 95° C. The mixture became homogeneous within minutes. After 24 h, the mixture was cooled to ambient and concentrated at reduced pressure to deposit a tan oil. The product was purified by flash chromatography (silica gel, 75% dichloromethane/25% ether), followed by recrystallization from a mixture of 100 mL of methanol plus 40 mL of water. The product was obtained as 9.1 g (41%) of an off-white solid. 1H NMR (CDCl3) δ 2.97 (t, J=5.5, 2H), 4.12 (t, J=5.5, 2H),4.1 (br s, 1H), 5.24 (d, J=10.8, 1H), 5.30 (s, 2H), 5.71 (d, J=17.6, 1H), 6.7 (m, 1H), 7.00 (d, J=8.1, 2H), 7.2 (m,3H) 7.34 (d, J= 8.2, 2H), 7.73 (m, 1H). ES−MS m/e 279+ (M+1).

Workup

waitThe mixture became homogeneous within minutes
temperaturethe mixture was cooled to ambient and
concentrationconcentrated at reduced pressure
customThe product was purified by flash chromatography (silica gel, 75% dichloromethane/25% ether)
customfollowed by recrystallization from a mixture of 100 mL of methanol plus 40 mL of water

Sources & evidence

ORD record: ord-663caedb61864afbb3a08b99624d2ecc
Source dataset: uspto-grants-2004_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06749977B1

Reaction notes

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