methyl 2-[(2'-oxo-5,6-dihydrospiro[benzo[1,2-b:5,4-b']difuran-3,3'-indol]-1'(2'H)-yl)methyl]benzoate → (2'-oxo-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3'-indol]-1'(2'H)-yl)acetic acid

Participants

Reaction Steps

Following the procedure as described in EXAMPLE 11.30 and making non-critical variations using ethyl (2′-oxo-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-1′(2′H)-yl)acetate to replace methyl 2-[(2′-oxo-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-1′(2′H)-yl)methyl]benzoate, (2′-oxo-2,3-dihydrospiro[furo[2,3-g][1,4]benzodioxine-8,3′-indol]-1′(2′H)-yl)acetic acid was obtained (83%): mp 193-196° C. (water); 1H NMR (300 MHz, DMSO-d6) δ 7.26-7.21 (m, 1H), 7.09-7.07 (m, 1H), 6.99-6.91 (m, 2H), 6.45 (s, 1H), 6.27 (s, 1H), 4.66 (ABq, 2H), 4.29-4.05 (m, 6H); MS (ES+) m/z 353.7 (M+1).

Provenance & Evidence