p-Toluenesulfonic acid → [3-(5,6-dimethoxy-1H-benzoimidazol-2-yl)-propyl]-methyl-carbamic acid benzyl ester

HRID 220240Notes

Reaction equation

[CH2:1]([O:8][C:9](=[O:29])[N:10]([CH2:12][CH2:13][CH2:14][C:15](=O)[NH:16][C:17]1[CH:22]=[C:21]([O:23][CH3:24])[C:20]([O:25][CH3:26])=[CH:19][C:18]=1[NH2:27])[CH3:11])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.CC1C=CC(S(O)(=O)=O)=CC=1.C([O-])(O)=O.[Na+]>C1(C)C=CC=CC=1.CN(C=O)C>[CH2:1]([O:8][C:9](=[O:29])[N:10]([CH2:12][CH2:13][CH2:14][C:15]1[NH:27][C:18]2[CH:19]=[C:20]([O:25][CH3:26])[C:21]([O:23][CH3:24])=[CH:22][C:17]=2[N:16]=1)[CH3:11])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

Conditions

Temperature: 150 °C

Procedure

To a mixture of crude [3-(2-amino-4,5-dimethoxy-phenylcarbamoyl)-propyl]-methyl-carbamic acid benzyl ester acid (obtained from 4-(methylamino)butyric acid and benzylchloroformate) in 6 mL toluene were added a few drops of DMF and 358 mg of TsOH and the reaction mixture was heated at 150° C. for 2 h in the microwave. Saturated aq. NaHCO3 solution was added, the phases were separated and the organic phase was washed with brine. The combined organic phases were dried over MgSO4, and concentrated in vacuo. Purification by CC EtOAc-MeOH (95:5) yielded 0.65 g of [3-(5,6-dimethoxy-1H-benzoimidazol-2-yl)-propyl]-methyl-carbamic acid benzyl ester as brown oil.

Workup

customthe phases were separated
washthe organic phase was washed with brine
dry with materialThe combined organic phases were dried over MgSO4
concentrationconcentrated in vacuo
customPurification by CC EtOAc-MeOH (95:5)

Sources & evidence

ORD record: ord-875ab622fc53447f9e63cb36d9e12636
Source dataset: uspto-grants-2012_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08202885B2

Reaction notes

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