3-(7-hydroxy-4-methyl-3,4-dihydro-2H-1,4-benzoxazin-6-yl)-1-[(2R)-tetrahydrofuran-2-ylmethyl]-1,3-dihydro-2H-indol-2-one trifluoroacetate 、
1-(diphenylmethyl)-3-(2-hydroxy-4-methoxy-5-methylphenyl)-1,3-dihydro-2H-indol-2-one 以1-methyl-1′-[(2R)-tetrahydrofuran-2-ylmethyl]-2,3-dihydro-1H-spiro[furo[3,2-g][1,4]benzoxazine-8,3′-indol]-2′(1′H)-one was obtained (72%) as a colorless solid的产率得到1-methyl-1'-[(2R)-tetrahydrofuran-2-ylmethyl]-2,3-dihydro-1H-spiro[furo[3,2-g][1,4]benzoxazine-8,3'-indol]-2'(1'H)-one