3,4-二氢-2H-吡喃 、
(5-hydroxymethyl-2-nitro-4-trifluoromethyl-phenyl)-carbamic acid tert-butyl ester 、 [2-nitro-5-(tetrahydro-pyran-2-yloxymethyl)-4-trifluoromethyl-phenyl]-carbamic acid tert-butyl ester 在
p-TsOH 作用下,
以
4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran 为溶剂,
生成 [2-amino-5-(tetrahydro-pyran-2-yloxymethyl)-4-trifluoromethyl-phenyl]-carbamic acid tert-butyl ester