1'-(diphenylmethyl)-6-methoxy-5-methylspiro[1-benzofuran-3,3'-indol]-2'(1'H)-one → 6'-fluoro-5,6-dihydrospiro[benzo[1,2-b:5,4-b']difuran-3,3'-indol]-2'(1'H)-one

Participants

Reaction Steps

Following the procedure as described in EXAMPLE 3 and making non-critical variations using 1′-(diphenylmethyl)-6′-fluoro-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-2′(1′H)-one to replace 1′-(diphenylmethyl)-6-methoxy-5-methylspiro[1-benzofuran-3,3′-indol]-2′(1′H)-one, 6′-fluoro-5,6-dihydrospiro[benzo[1,2-b:5,4-b′]difuran-3,3′-indol]-2′(1′H)-one was obtained (71%) as a colorless solid: mp 249-251° C. (diethyl ether); 1H NMR (300 MHz, DMSO-d6) δ10.74 (s, 1H), 7.18-7.13 (m, 1H), 6.79-6.42 (m, 2H), 6.55 (s, 1H), 6.42 (s, 1H), 4.74 (ABq, 2H), 4.52 (t, J=9.0 Hz, 2H), 2.99 (t, J=9.0 Hz, 2H); MS (ES+) m/z 298.0 (M+1).

Provenance & Evidence