ethyl (4'-bromo-6,6-dimethyl-2'-oxo-5,6-dihydrospiro[benzo[1,2-b:5,4-b']difuran-3,3'-indol]-1'(2'H)-yl)acetate → (4'-bromo-6,6-dimethyl-2'-oxo-5,6-dihydrospiro[benzo[1,2-b:5,4-b']difuran-3,3'-indol]-1'(2'H)-yl)acetic acid

Participants

Reaction Steps

Following the procedure as described in EXAMPLE 2, and making non-critical variations using ethyl (4′-bromo-6,6-dimethyl-2′-oxo-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-1′(2′H)-yl)acetate to replace ethyl (2′-oxospiro[furo[2,3-f][1,3]benzodioxole-7,3′-indol]-1′(2′H)-yl)acetate, the title compound was obtained. The product was used directly in the next step.

Provenance & Evidence