1'-(diphenylmethyl)-6-methoxy-5-methylspiro[1-benzofuran-3,3'-indol]-2'(1'H)-one → 2,3-dihydrospiro[furo[2,3-f][1,4]benzodioxine-7,3'-indol]-2'(1'H)-one

Participants

Reaction Steps

Following the procedure as described in EXAMPLE 3 and making non-critical variations using 1′-(diphenylmethyl)-2,3-dihydrospiro[furo[2,3-f][1,4]benzodioxine-7,3′-indol]-2′(1′H)-one to replace 1′-(diphenylmethyl)-6-methoxy-5-methylspiro[1-benzofuran-3,3′-indol]-2′(1′H)-one, 2,3-dihydrospiro[furo[2,3-f][1,4]benzodioxine-7,3′-indol]-2′(1′H)-one was obtained (30%) as a colorless solid: mp>250° C.; 1H NMR (300 MHz, DMSO-d6) δ 10.56 (s, 1H), 7.23 (ddd, J=7.7, 7.7, 0.5 Hz, 1H), 7.13 (d, J=7.2 Hz, 1H), 6.99-6.90 (m, 2H), 6.21 (ABq, 2H), 4.76 (ABq, 2H), 4.26 (s, 4H); 13C NMR (75 MHz, DMSO-d6) δ 178.3, 148.7, 144.5, 141.8, 132.3, 129.2, 128.6, 123.8, 122.5, 122.2, 114.1, 109.7, 80.2, 64.1, 63.9, 57.7; MS (ES+) m/z 295.9 (M+1).

Provenance & Evidence