5 g of 3-methoxy-2-methoxymethyl-2-methyl-propionic acid (prepared as in EP609058) were dissolved in 49 mL of DCM and 12 mL of THF. 11.4 mL of DIPEA, 5.84 g of HOBt, 7.07 g of EDCI and 5.45 g of 3,3-diethoxy-propylamine were added sequentially. The mixture was stirred for 23 h at rt, diluted with DCM and washed with sat. NaHCO3. The organic phase was dried over anh. Na2SO4 and concentrated in vacuo. The resulting crude material was purified by CC using heptane/EtOAc from 3/1 to 0/1 as eluant to yield 7.25 g of N-(3,3-diethoxy-propyl)-3-methoxy-2-methoxymethyl-2-methyl-propionamide as a yellowish oil.
