Butanal → 7-[Butyl(4-methoxyphenyl)amino]-1-methyl-1,3-dihydro-2H-benzimidazol-2-one

HRID 2235548Notes

Reaction equation

[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([NH:9][C:10]2[C:15]3[N:16]([CH3:20])[C:17](=[O:19])[NH:18][C:14]=3[CH:13]=[CH:12][CH:11]=2)=[CH:5][CH:4]=1.[CH:21](=O)[CH2:22][CH2:23][CH3:24].C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+]>ClC(Cl)C.C(O)(=O)C.C(OCC)(=O)C>[CH2:21]([N:9]([C:6]1[CH:7]=[CH:8][C:3]([O:2][CH3:1])=[CH:4][CH:5]=1)[C:10]1[C:15]2[N:16]([CH3:20])[C:17](=[O:19])[NH:18][C:14]=2[CH:13]=[CH:12][CH:11]=1)[CH2:22][CH2:23][CH3:24]

Participants

Conditions

Temperature: 70 °C

Procedure

A mixture of 0.100 g (0.37 mmol) of 7-[(4-methoxyphenyl)amino]-1-methyl-1,3-dihydro-2H-benzimidazol-2-one and 0.13 mL (1.5 mmol) of butyraldehyde in 15 mL of dichloroethane was treated with four drops of glacial acetic acid and 0.31 g (1.5 mmol) of sodium triacetoxyborohydride. The mixture was heated to 70° C. for five days. The mixture was diluted with ethyl acetate and was washed successively with saturated sodium bicarbonate and brine before being dried over sodium sulfate. The solution was filtered, concentrated in vacuo and the resulting crude oil was purified by flash chromatography eluting with a 97% dichloromethane/methanol mixture to give 0.70 g (45%) of the title compound as a yellow sticky semi-solid that was used without further purification.

Workup

washwas washed successively with saturated sodium bicarbonate and brine
dry with materialbefore being dried over sodium sulfate
filtrationThe solution was filtered
concentrationconcentrated in vacuo
customthe resulting crude oil was purified by flash chromatography
washeluting with a 97% dichloromethane/methanol mixture

Sources & evidence

ORD record: ord-0a7d96813fc540c6b66a90fa5d101508
Source dataset: uspto-grants-2010_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07714009B2

Reaction notes

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