Diisopropylethylamine → 3-Cyclohexyl-5-ethoxy-1,3-dihydro-1-[2-methoxy-4-[N-(2-dimethylamino-1,1-dimethylethyl)carbamoyl]benzyl]-2H-benzimidazol-2-one

Participants

Reaction Steps

A mixture of 1.5 g of the compound obtained in Example 15 Step B, 1 g of 2-dimethylamino-1,1-dimethylethylamine (synthesized according to J. Am. Chem. Soc., 1946, 68, 12-14), 1.6 g of BOP and 2 g of DIPEA in 20 ml of DCM is left stirring for 1 hour at RT. The reaction mixture is concentrated under vacuum, the residue is extracted with EtOAc, the organic phase is washed with 1N NaOH solution, with water and dried over Na2SO4, and the solvent is evaporated off under vacuum. The residue is chromatographed on silica, eluting with a DCM/MeOH mixture (98/2; v/v). 0.15 g of the expected product is obtained after crystallization from iso ether, mp=161° C.

Provenance & Evidence