合成路线1

The reaction of 3-(2,2-dimethoxyethyl)-2-phenyl-4-oxo-3,4-dihydropyrimidine-5-carboxylic acid (IX) with isobutyl chloroformate and hydroxylamine gives the corresponding hydroxamic acid (X), which is acylated with Ac2O in pyridine to yield the acetoxy compound (XI). The degradation of (XI) by reaction with DBU in refluxing THF affords the amine (XII), which is protected with benzyl chloroformate (XIII) and NaHCO3, providing the carbamate (XIV). The hydrolysis of the dimethylacetal group of (XIV) with HCl in hot acetic acid gives the acetaldehyde derivative (XV), which is oxidized with NaClO2 in tert-butanol/water yielding the corresponding acetic acid derivative (XVI). The condensation of (XVI) with the intermediate amine (VIII) by means of ethyl chloroformate and NMM in THF affords the amide (XVII), which is hydrogenolyzed with H2 over Pd/C in order to eliminate its carbamate protecting group and provide the target racemic 285811.