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NMR (CDCl3, 300 MHz, d ppm): 2.23–2.27 (m, 3H, CH2), 2.32–
2.43 (m, 1H, CH2), 2.60–2.71 (m, 2H, CH2), 2.83–3.022 (m, 2H,
CH2), 3.73 (m, 7H, CH2 and 2xOCH3), 5.79 (t, J ¼ 4.5 Hz, 1H,
]CH), 6.69 (t, 2H, J ¼ 2.1 Hz, ArH), 7.07 (dd, J ¼ 3.0 Hz and 8.4
Hz, 2H, ArH), 7.16 (d, J ¼ 8.1 Hz, 1H, ArH), 7.58 (d, J ¼ 2.4 Hz,
1H, ArH); 13C NMR (CDCl3, 75 MHz, d ppm): 23.95 (CH2), 27.54
(CH2), 27.73 (CH2), 29.37 (CH2), 50.84 (CH), 55.71 (OCH3), 55.91
(OCH3), 109.90 (Ar–H), 110.58 (Ar–H), 111.42 (]CH), 122.21
(Ar–H), 128.11 (Ar–H), 128.72 (Ar–H), 129.57, 130.40 (Ar–H),
134.23, 135.36, 135.64, 137.09, 158.64 (phenolic), 158.84
(phenolic), 199.38 (C]O); MS: 335.4 [MH+]; anal. calcd
(C22H22O3): C, 79.02; H, 6.63; found: C, 78.93; H, 6.58%.
6,60,7,70-Tetramethoxy-3,30,4,40-tetrahydro-1,20-binaphthyl-
10-(20H)-one (10f). Creamy white solid; yield: 72%; Rf: 0.13 (20%
ethyl acetate–hexane); mp: 182–183 ꢀC; IR (KBr, nmax/cmꢁ1): 1668
(C]O); 1H NMR (CDCl3, 300 MHz, d ppm): 1.55 (s, 1H, CH), 2.18–
2.38 (m, 4H, CH2), 2.66 (t, J ¼ 7.8 Hz, 2H, CH2), 2.78–3.011 (m, 2H,
CH2), 3.75 (s, 3H, OCH3), 3.80 (s, 3H, OCH3), 3.92 and 3.94 (s, 6H,
2xOCH3), 5.64 (t, J ¼ 4.2 Hz, 1H, ]CH), 6.68, 6.703 & 6.736 (s, 3H,
ArH), 7.59 (s, 1H, ArH); 13C NMR (CDCl3, 75 MHz, d ppm): 23.72
(CH2), 27.73 (CH2), 28.37 (CH2), 29.34 (CH2), 50.42 (CH), 56.37
(OCH3), 56.43 (OCH3), 56.46 (OCH3), 56.57 (OCH3), 108.52 (Ar–H),
109.25 (Ar–H), 110.62 (Ar–H), 112.08 (Ar–H), 125.22 (]CH),
126.73, 127.05, 130.39, 135.38, 139.38, 147.54 (phenolic), 148.16
(phenolic), 148.51 (phenolic), 154.05 (phenolic), 198.42 (C]O);
MS: 395 [MH+]; anal. calcd (C24H26O5): C, 73.08; H, 6.64; found: C,
72.98; H, 6.59%.
General procedure for the synthesis of partially reduced
bisindene (12)
Compound 11 (0.59 mmol) was treated with borontribromide
(BBr3, 0.30 mL, 1.76 mmol) under similar reaction conditions to
those discussed above for 10. The crude material obtained from
the reaction was puried by column chromatography using
silica gel (100–200 mesh size) and ethyl acetate–hexane (4 : 96)
as the eluent, which yielded pure compound 12.
2-[3-(4-Methoxyphenyl)-2,3-dihydro-1H-inden-1-ylidene]-3-
(4-methoxyphenyl)-2,3-dihydro-1H-inden-1-one (12a). White
solid; yield 80%; Rf: 0.15 (30% ethyl acetate–hexane); mp 62–63
ꢀC; IR (KBr, nmax/cmꢁ1): 1680 (C]O); 1H NMR (CDCl3, 300 MHz, d
ppm): 0.88 (t, 1H, J ¼ 6.6 Hz, CH of CH2), 1.25 (t, 1H, J ¼ 6.9 Hz,
CH of CH2), 3.74 (s, 3H, OMe), 3.78 (s, 3H, OMe), 4.46 (t, 1H, J ¼
4.2 Hz, CH), 5.36 (s, 1H, CH), 6.80–6.84 (m, 3H, ArH), 6.98–7.15
(m, 4H, ArH), 7.23–7.39 (m, 7H, ArH), 7.42–7.57 (m, 1H, ArH),
7.81 (d, 1H, J ¼ 7.8, ArH); 13C NMR (CDCl3, 75 MHz, d ppm): 43.64
(CH2), 48.89 (CH), 49.03 (CH), 55.58 (OCH3), 55.67 (OCH3), 114.41
(2xAr–H), 114.70 (Ar–H), 114.92 (Ar–H), 124.05 (Ar–H), 125.10,
125.91 (Ar–H), 126.30 (Ar–H), 127.38 (Ar–H), 127.62 (Ar–H), 127.88
(Ar–H), 128.66 (2xAr–H), 129.07 (2xAr–H), 129.96, 131.12 (Ar–H),
134.57 (Ar–H), 135.33, 136.64, 137.69, 138.00, 139.65, 156.22,
158.82, 196.11 (C]O); MS: 457 [M ꢁ H]+; anal. calcd (C32H26O3):
C, 83.82; H, 5.72; found: C, 83.70; H, 5.66%.
2-(5,6-Dimethoxy-2,3-dihydro-1H-inden-1-ylidene)-5,6-dime-
thoxy-2,3-dihydro-1H-inden-1-one (12b). Yellow solid; yield:
74%; Rf: 0.16 (30% ethyl acetate–hexane); mp: 212–213 C; IR
ꢀ
5-Methoxy-3-(5-methoxy-2,2-dimethyl-2H-chromen-4-yl)-2,2-
dimethylchroman-4-one (10g). White solid; yield: 70%; Rf: 0.21
(10% acetone–hexane); mp: 127–128 ꢀC; IR (KBr, nmax/cmꢁ1):
(KBr, nmax/cmꢁ1): 1666 (C]O); 1H NMR (CDCl3, 300 MHz, d
ppm): 3.09 (d, J ¼ 5.1 Hz, 2H, CH2), 3.58 (d, J ¼ 5.1 Hz, 2H, CH2),
3.96 & 4.01 (s, 14H, 4xOCH3 and CH2), 6.92 (s, 1H, ArH), 7.01 (s,
1H, ArH), 7.28 (s, 1H, ArH), 7.30 (s, 1H, ArH); 13C NMR (CDCl3,
75 MHz, d ppm): 31.33 (CH2), 32.47 (CH2), 32.72 (CH2), 56.38
(OCH3), 56.49 (OCH3), 56.58 (OCH3), 56.66 (OCH3), 104.98 (Ar–
H), 107.51 (Ar–H), 108.05 (Ar–H), 108.42 (Ar–H), 124.75, 133.43,
133.58, 143.23, 146.32, 148.98, 149.77 (phenolic), 152.24
(phenolic), 154.48 (phenolic), 154.74 (phenolic), 194.36 (C]O);
MS: 367 [M + H]+; HRMS (ESI): calcd 367.1545 [MH+]; found:
367.1531; anal. calcd (C22H22O5): C, 72.12; H, 6.05; found: C,
72.01; H, 6.01%.
1
1667 (C]O); H NMR (acetone-d6, 300 MHz, d ppm): 1.06 (s,
3H, CH3), 1.21 (s, 3H, CH3), 1.30 (s, 3H, CH3), 1.35 (s, 3H, CH3),
3.64 (s, 3H, OCH3), 3.68 (s, 1H, CH), 3.76 (s, 3H, OCH3), 5.27 (s,
1H, ]CH), 6.22 (d, 1H, J ¼ 1.5 Hz, ArH), 6.37 (s, 2H, ArH), 6.49
(d, 1H, J ¼ 1.2 Hz, ArH), 7.31 (d, 1H, J ¼ 8.4 Hz, ArH), 7.61 (d,
1H, J ¼ 8.7 Hz, ArH); 13C NMR (acetone-d6, 75 MHz, d ppm):
24.37 (CH3), 26.36 (CH3), 26.84 (CH3), 27.23 (CH3), 55.10
(OCH3), 55.65 (OCH3), 75.74, 81.86, 101.64 (Ar–H), 102.72 (Ar–
H), 106.75 (Ar–H), 109.80 (Ar–H), 114.20, 116.16, 125.16 (Ar–H),
127.92, 128.89 (]CH), 155.03, 161.29 (phenolic), 161.63
(phenolic), 166.74, 190.04 (C]O); MS: 395 [MH+]; anal. calcd
(C24H26O5): C, 73.08; H, 6.64; found: C, 72.98; H, 6.59%.
3,40-Bithiochroman-4-one (10h). Pink solid; yield: 73%; Rf:
5-Methoxy-2-(5-methoxy-2,3-dihydro-1H-inden-1-ylidene)-
2,3-dihydro-1H-inden-1-one (12c). Yellow solid; yield: 89%; Rf:
0.29 (30% ethyl acetate–hexane); mp: 175–176 ꢀC; IR (KBr, nmax
/
cmꢁ1): 1671 (C]O); 1H NMR (CDCl3, 300 MHz, d ppm): 3.09 (t, J
¼ 5.7 Hz, 2H, CH2), 3.53 (t, J ¼ 5.7 Hz, 2H, CH2), 3.86 and 3.90 (s,
8H, 2xOCH3 and CH2), 6.87–6.96 (m, 4H, ArH), 7.66 (d, J ¼ 8.4
Hz, 1H, ArH), 7.76 (d, J ¼ 8.4 Hz, 1H, ArH); 13C NMR (CDCl3, 75
MHz, d ppm): 31.47 (CH2), 32.15 (CH2), 33.40 (CH2), 55.83
(OCH3), 55.94 (OCH3), 109.89 (Ar–H), 110.20 (Ar–H), 114.48 (Ar–
H), 115.00 (Ar–H), 124.90, 125.50 (Ar–H), 127.33 (Ar–H), 133.75,
134.20, 151.51, 153.83, 154.43, 162.13 (phenolic), 164.63
(phenolic), 194.15 (C]O); MS: 307.3 [MH+]; anal. calcd
(C20H18O3): C, 78.41; H, 5.92; found: C, 78.31; H, 5.89%.
0.46 (10% acetone–hexane); mp: 119–120 ꢀC; IR (KBr, nmax
/
cmꢁ1): 1674 (C]O); 1H NMR (CDCl3, 300 MHz, d ppm):
3.150–3.29 (m, 2H, CH2), 3.36–3.54 (m, 2H, CH2), 4.09 (dd, J ¼
3.6 and 11.4 Hz, 1H, CH), 5.88 (t, J ¼ 5.4 Hz, 1H, ]CH),
7.096–7.30 (m, 3H, ArH), 7.33–7.36 (m, 1H, ArH), 7.38–7.43
(m, 3H, ArH), 8.18 (dd, J ¼ 1.5 and 8.1 Hz, 1H, Ar–H); 13C NMR
(CDCl3, 75 MHz, d ppm): 25.26 (CH2), 32.02 (CH2), 52.48 (CH),
122.55 (]CH), 125.54 (2xAr–H), 126.14 (Ar–H), 128.02 (Ar–H),
128.10 (Ar–H), 128.58 (Ar–H), 130.28 (Ar–H), 131.71, 133.03,
133.77 (Ar–H), 134.62, 136.59, 142.39, 194.87 (C]O); MS:
311.2 [MH+]; HRMS (ESI): calcd 311.0564 [MH+]; found:
311.0546; anal. calcd (C18H14OS2): C, 69.64; H, 4.55; found: C,
69.54; H, 4.51%.
6-Methoxy-2-(6-methoxy-2,3-dihydro-1H-inden-1-ylidene)-
2,3-dihydro-1H-inden-1-one (12d). Yellow sꢀolid, yield: 72%;
Rf: 0.30 (20% acetone–hexane); mp: 157–158 C; IR (KBr, nmax
/
cmꢁ1): 1679 (C]O); 1H NMR (CDCl3, 300 MHz, d ppm): 3.07 (t, J
This journal is © The Royal Society of Chemistry 2014
RSC Adv., 2014, 4, 24619–24634 | 24629