反应详情

A solution is prepared from 3.8 g of 2-amino-3-(5-benzyloxyindol-3-yl)-4-methoxybutyric acid isopropyl ester (10 mmol) in 80 ml of xylene and added dropwise to a suspension of 360 mg of paraformaldehyde in 60 ml of xylene heated for 45 minutes to 100° C. The mixture is then refluxed for 2 hours on a water trap. After concentration, the residue is chromatographed over silica gel with methylene chloride:acetone=1:1 as the eluent, yielding 2.5 g of 6-benzyloxy-4-methoxymethyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid isopropyl ester (65% yield as an oil); or

1. temperatureheated for 45 minutes to 100° C
2. temperatureThe mixture is then refluxed for 2 hours on a water trap
3. concentrationAfter concentration
4. customthe residue is chromatographed over silica gel with methylene chloride