1'-(diphenylmethyl)-6,7-dihydrospiro[benzo[1,2-b:4,5-b']difuran-3,3'-indol]-2'(1'H)-one → 5,6-dihydro-2H-spiro[benzofuro[6,5-b]furan-3,3'-indolin]-2'-one

Participants

Reaction Steps

Following the procedure as described in EXAMPLE 1.49, and making non-critical variations using 1′-(diphenylmethyl)-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-2′(1′H)-one to replace 1′-(diphenylmethyl)-6,7-dihydrospiro[benzo[1,2-b:4,5-b′]difuran-3,3′-indol]-2′(1′H)-one, the title compound was obtained (68%): mp 208-210° C.; 1H NMR (300 MHz, DMSO-d6) δ 10.53 (s, 1H), 7.39-6.76 (m, 4H), 6.45 (s, 1H), 6.35 (s, 1H), 4.68 (ABq, 2H), 4.45 (t, 2H), 2.92 (t, 2H); MS (ES+) m/z 280.2 (M+1).

Provenance & Evidence