| 摘要 |
<p>N-Acylated derivs. of pyrrdidine 2-carboxylic acid, of formula (I) in which R1 and R2 are H, lower alkyl or other, R3 is 3C alkyl or other, and R4 is OH or opt branched 3C alkoxy are made by (a) treating the acid, with its amino function protected with benzyl carbamate,with 1-(2-nitro benzene sulphonyloxy) 6-nitro benzo-triazole; (b) The carboxylic deriv. is treated with an amino-acid which has its carboxylic gp protected as the benzyl ester, both (a) and (b) being carried out in the presence of a base, e.g. triethylamine or pyridine, in a solvent, e.g. THF or dioxane, at 0-100 deg.C and (c) The prod. is hydrogenated in presence of Pd/C to hydrolyse the protective gps and obtain (I).</p> |
