反应详情

Step 1. A solution of ({[3-methoxy-4-(3-o-tolylureido)phenyl]-acetyl}-amino)-acetic acid [50 g, Reference Example 3] and 3-(3,4-dimethoxy-benzylamino)-propionic acid ethyl ester [36 g, Reference Example 2(a)] in dimethylformamide (500 ml) was treated with [O-(7-azabenzotriazol-1-yl)-1,1,3,3,-tetramethyluronium hexafluorophosphate] (53.2 g) and diisopropylethylamine (59 ml). After stirring at ambient temperature for 3 hours the reaction mixture was evaporated to dryness and the residue was treated with water (3L). The mixture was extracted twice with ethyl acetate (1L) and then concentrated to dryness. The residue was subjected to flash chromatography on silica eluting initially with ethyl acetate and then with a mixture of ethyl acetate and methanol (9:1, v/v) to give 3-[N-(3,4-dimethoxybenzyl)-2-{2-[3-methoxy-4-(3-o-tolylureido)phenyl]acetylamino}acetamido]propionic acid ethyl ester as a yellow oil (49 g).

1. customwas evaporated to dryness
2. additionthe residue was treated with water (3L)
3. extractionThe mixture was extracted twice with ethyl acetate (1L)
4. concentrationconcentrated to dryness
5. additionwith a mixture of ethyl acetate and methanol (9:1