3,5-diethoxy-4-(morpholin-4-yl)benzaldehyde 、 tert-butyl 7-(4-(ethoxycarbonyl)-4-methylpiperidin-1-yl)-5-oxa-2,6-diazaspiro[3.4]oct-6-ene-2-carboxylate 以the title compound was obtained in the similar manner as in Step G of Example 1的产率得到ethyl 1-(2-(3,5-diethoxy-4-(morpholin-4-yl)benzyl)-5-oxa-2,6-diazaspiro[3.4]oct-6-en-7-yl)-4-methylpiperidine-4-carboxylate