反应详情

The hapten p-(carboxymethyl)ritodrine (Hapten E) was prepared in four steps according to FIG. 7 of the accompanying drawings, from 2-(4-hydroxyphenyl)ethanol 17. The reaction of 17 with t-butyl bromoacetate in acetonitrile in the presence of potassium carbonate at 60° C. gives 2-[4-(t-butoxycarbonylmethoxy)phenyl]ethanol 18. The oxidation of the alcohol 18 with pyridinium chlorochromate (pcc) in dichloromethane gives the 2-[4-(t-butoxycarbonylmethoxy)phenyl]ethanal 19. The ester 20, obtained by condensation of the aldehyde 19 with α-(1-aminoethyl)-4-hydroxybenzyl alcohol hydrochloride 13 in methanol in the presence of sodium cyanoborohydride and triethylamine. Deprotection of the t-butyl protecting group of the ester 20 with 4 M HCl in dioxane at room temperature gave Hapten E in moderate yield.