354
N. Micale et al. / Il Farmaco 58 (2003) 351ꢀ355
/
4.1.4. Synthesis of (Z)-6-[acetylhydrazono-(4-
aminophenyl)-methyl]-1,3-benzodioxole-5-acetic acid
methyl ester (7)
1H, H-4), 7.60 (d, 2H, Jꢃ
8.8, H-3?-5?). Anal. C17H16N2O6 (C, H, N).
/
8.8, H-2?-6?), 8.21 (d, 2H, Jꢃ
/
To a solution of 6-(4-nitrobenzoyl)-1,3-benzodioxole-
5-acetic acid methyl ester (16) (200 mg, 0.58 mmol) [8] in
MeOH (25 ml), AcNHNH2 (86 mg, 1.16 mmol) and a
catalytic amount of 6 N HCl were added. The reaction
mixture was heated to reflux for 48 h. After cooling, the
solvent was removed under reduced pressure and the
residue was subjected to chromatography eluting with
EtOAc/cyclohexane (1:1) to afford the acetylhydrazono
derivative which was successively reduced with a proce-
dure similar to that reported for compound 5, to give
compound 7.
4.1.7. Synthesis of 6-[(4-nitrophenyl)-hydroxymethyl]-
1,3-benzodioxole-5-acetic acid hydrazide (10)
With the same procedure described for the synthesis
of 9, 10 was prepared from 19 using hydrazine as
reagent.
m.p. 92ꢀ
97% (214 mg); H NMR: 1.63 (bs, 2H, NH2), 3.37 and
3.68 (dd, 2H, Jꢃ 15.1, CH2-5), 4.92 (bs, 1H, OH),
5.94 (s, 2H, OCH2O), 6.04 (s, 1H, CH), 6.49 (s, 1H, H-
7), 6.66 (s, 1H, H-4), 7.16 (bs, 1H, NH), 7.58 (d, 2H, Jꢃ
8.5, H-2?-6?), 8.22 (d, 2H, Jꢃ8.5, H-3?-5?). Anal.
C16H15N3O6 (C, H, N).
/
94 8C; Rfꢃ
/0.60 (EtOAc/acetone, 8:2); yield
1
/
ꢁ
/
/
/
m.p. 106ꢀ
/
109 8C; Rfꢃ0.58 (EtOAc); yield 55% (118
/
mg); 1H NMR: 2.40 (s, 3H, COCH3), 3.30 (m, 2H,
CH2), 3.53 (s, 3H, OCH3), 3.96 (bs, 2H, NH2), 6.05 (m,
4.1.8. Synthesis of 6-(4-nitrobenzoyl)-1,3-benzodioxole-
5-methylacetamide (11)
2H, OCH2O), 6.56 (s, 1H, H-3), 6.60 (d, 2H, Jꢃ
/8.0, H-
3?-5?), 6.91 (s, 1H, H-6), 7.34 (d, 2H, Jꢃ8.5, H-2?-6?),
8.19 (bs, 1H, NH). Anal. C19H19N3O5 (C, H, N).
/
To a suspension of 9 (200 mg, 0.58 mmol) in dry
benzene (25 ml) was added activated MnO2 (50 mg, 0.58
mmol) and the resulting mixture was stirred under reflux
for 2 h. After cooling, the mixture was filtered-off on a
Celite pad and the solvent was removed under reduced
pressure. The crude product was purified by column
chromatography with EtOAc/cyclohexane (80:20) to
give 11.
4.1.5. Synthesis of 6-(4-aminobenzyl)-1,3-benzodioxole-
5-dimethylacetamide (8)
Compound 18 (200 mg, 0.61 mmol) was subjected to
hydrolysis and converted into the corresponding acyl
chloride with a procedure previously reported [10], then
dissolved in dry benzene (25 ml) and treated with an
excess of dimethylamine at reflux (2 h). The solvent was
removed in vacuo and the residue was purified by
column chromatography with CCl4/EtOAc/i-PrOH
(70:20:10) as eluant. The reduction of the nitro group
was accomplished with ammonium formate and Raney-
Ni to give a crude which was purified by treatment with
acetone.
m.p. 171ꢀ
/
173 8C; Rfꢃ0.51 (EtOAc/cyclohexane,
/
1
8:2); yield 68% (135 mg); H NMR: 2.75 (d, 3H, Jꢃ
/
4.7, NHCH3), 3.58 (s, 2H, CH2-5), 6.05 (s, 2H, OCH2O),
6.76 (s, 1H, H-7), 6.92 (m, 1H, NHCH3), 7.03 (s, 1H, H-
4), 7.92 (d, 2H, Jꢃ
/
8.8, H-2?-6?), 8.31 (d, 2H, Jꢃ8.8, H-
/
3?-5?). Anal. C17H14N2O6 (C, H, N).
4.1.9. Synthesis of 6-(4-nitrobenzoyl)-1,3-benzodioxole-
5-acetic acid hydrazide (12)
Compound 12 was prepared from 10, with the same
procedure described for the synthesis of 11.
m.p. 120ꢀ
/
121 8C; Rfꢃ0.37 (EtOAc); yield 53% (106
/
mg); 1H NMR: 2.80 and 2.94 (2s, 6H, N(CH3)2), 3.52 (s,
2H, CH2-5), 3.58 (bs, 2H, NH2), 3.76 (s, 2H, CH2-6),
m.p. 118ꢀ
/
120 8C; Rfꢃ0.51 (EtOAc/cyclohexane,
/
5.91 (s, 2H, OCH2O), 6.60 (d, 2H, Jꢃ
(2s, 2H, H-4 and H-7), 6.68 (d, 2H, Jꢃ
Anal. C18H20N2O3 (C, H, N).
/
7.7, H-3?-5?), 6.62
8:2); yield 56% (111 mg); 1H NMR: 1.66 (bs, 2H,
NH2), 3.69 (s, 2H, CH2-5), 6.10 (s, 2H, OCH2O), 6.80 (s,
/
7.7, H-2?-6?).
1H, H-7), 7.26 (s, 1H, H-4), 8.01 (d, 2H, Jꢃ
/
8.8, H-2?-
6?), 8.39 (d, 2H, Jꢃ8.8, H-3?-5?), 10.37 (bs, 1H, NH).
/
4.1.6. Synthesis of 6-[(4-nitrophenyl)-hydroxymethyl]-
1,3-benzodioxole-5-methylacetamide (9)
Anal. C16H13N3O6 (C, H, N).
To a stirred solution of 19 (200 mg, 0.64 mmol) in
MeOH (25 ml), an excess of methyl amine was added
and the resulting mixture was refluxed for 1 h. Methanol
was removed under vacuum and the oil residue was
triturated by treatment with diethyl ether to afford a
white solid which was filtered-off to give 9 as pure
product.
4.2. Primary anticancer assay
Evaluation of cytotoxic activity of compounds 2ꢀ12
/
was performed at NCI. As primary anticancer assay, a
3-cell line panel consisting of MCF7 (breast), NCI-H460
(lung), and SF-268 (CNS) was used. Each cell line is
inoculated and preincubated on a microtiter plate. Test
agents are then added at a single 10ꢁ4 concentration
and the culture incubated for 48 h. End point determi-
nations are made with alamarBlue [11]. Results for each
test agent are reported as the percent of growth of the
treated cells when compared with the untreated control
m.p. 117ꢀ
yield 96% (211 mg); 1H NMR: 2.82 (d, 3H, Jꢃ
NHCH3), 3.37 and 3.71 (dd, 2H, Jꢃ 14.8, CH2-5),
/
119 8C; Rfꢃ
/
0.71 (EtOAc/acetone, 8:2);
/4.7,
/
ꢁ
/
5.25 (bs, 1H, OH), 5.78 (m, 1H, NHCH3), 5.93 (s, 2H,
OCH2O), 6.03 (s, 1H, CH), 6.50 (s, 1H, H-7), 6.65 (s,