10-(2-tert-butoxy-2-oxoethyl)-1-hydroxy-11-oxo-10,11-dihydrodibenzo[b,f][1,4]oxazepine-8-carboxylic acid methyl ester 、
溴乙酸叔丁酯 在
potassium carbonate 作用下,
以
DMF (N,N-dimethylformamide) 为溶剂,
以99%的产率得到1-(2-tert-butoxy-2-oxoethoxy)-10-(2-tert-butoxy-2-oxoethyl)-11-oxo-10,11-dihydrodibenzo[b,f][1,4]oxazepine-8-carboxylic acid methyl ester