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New Journal of Chemistry
Page 7 of 10
Journal Name
Acetylation of 1-aryl-isochromans. To a solution of isochroman (m/z, %): 386 (M+, 22), 344 (30), 302 (100).
DOI: 10.1039/C5NJ03133H
ARTICLE
(reaction scale: 100 mg) in dry pyridine (1.5 mL) was added acetic 1-Phenylisochroman-6,7-diyl diacetate (1e). Quantitative yield;
anhydride (1.5 mL). The mixture was kept under stirring at room colorless oil. Found C, 70.12; H, 5.22 %; M+, 326. C19H18O5 requires
temperature overnight. At the end, the mixture was poured into ice- C, 69.93; H, 5.56 %; M, 326. νmax/cm-1: 3031, 2933, 2855, 1770
water (5 mL), treated with 1 N HCl and extracted with ethyl acetate (acetate CO stretch), 1503, 1371, 1211, 1171, 1083. 1H-NMR (CDCl3,
(2 x 10mL). Finally, the combined organic phases were washed with 400 MHz) δ: 7.31-7.28 (m, 5H, Ph-H), 7.00 (s, 1H, Ph-H), 6.54 (s, 1H,
a saturated solution of NaCl and dried over anhydrous Na2SO4. After Ph-H), 5.65 (s, 1H, CH), 4.21-4.08 (m, 1H, CH), 3.95-3.84 (m, 1H, CH),
evaporation of the solvent under reduced pressure, pure sample of 3.14-3.01 (m, 1H, CH), 2.77-2.69 (m, 1H, CH), 2.24 (s, 3H, CH3), 2.15
isochroman derivative was obtained after purification by silica gel (s, 3H, CH3). 13C-NMR (CDCl3, 400 MHz)
δ
: 168.4, 168.3, 141,3,
chromatographic column using hexane/ethyl acetate = 3/1 as 140.7, 140.0, 136.0, 132.6, 128.9, 128.6, 128.4, 123.3, 121.6, 79.4,
eluent.
63.9, 28.3, 20.6, 20.5. GC/MS (m/z, %): 326 (M+, 22), 284 (15), 242
6-Methoxy-1-phenylisochroman-7-yl acetate (1a). Quantitative (100), 214 (30), 165 (90), 152 (20).
yield; colorless oil. Found: C, 73.05; H, 5.95 %; M+, 298. C18H18O4
requires C, 72.47; H, 6.08 %; M, 298. νmax/cm-1: 3002, 2944, 2853, Synthesis
of
1758 (acetate CO stretch), 1616, 1509, 1452, 1256, 1182, 1091. 1H- [1,3]dioxolo[4,5-g]isochromene (1f).20 Isochroman 7 was dissolved
NMR (CDCl3, 400 MHz) : 7.36-7.27 (m, 5H, Ph-H), 6.74 (s, 1H, Ph- in CHCl3 (6.5 mL), then 2,2-dimethoxypropane (544 l, 4.5 mmol)
2,2-dimethyl-5-phenyl-7,8-dihydro-5H-
δ
ꢀ
H), 6.40 (s, 1H, Ph-H), 5.64 (s, 1H, CH), 4.24-4.14 (m, 1H, CH), 3.94- and camphorsulphonic acid (19.36 mg, 0.09 mmol) were added. The
3.82 (m, 1H, CH), 3.80 (s, 3H, OCH3), 3.12-3.02 (m, 1H, CH), 2.78- mixture was kept under stirring at reflux temperature for 6 h. At the
2.68 (m, 1H, CH), 2.05 (s, 3H, CH3). 13C-NMR (CDCl3, 400 MHz)
δ:
end, the reaction was neutralized by shaking with NaHCO3
169.1, 149.7, 148.9, 141.8, 137.8, 132.4, 129.7, 128.8, 128.5, 128.2, (saturated solution) and the separated aqueous phases were
121.0, 112.2, 79.2, 63.9, 55.9, 28.7, 20.6. GC/MS (m/z, %): 298 (M+, extracted with diethyl ether (3 x 10 mL). The collected organic
20), 256 (70), 228 (32), 179 (100).
phases were dried over anhydrous Na2SO4 and evaporated in vacuo
crude mixture. After the purification on
1-(4’-Acetoxyphenyl)-6-methoxyisochroman-7-yl acetate (1b). obtaining
a
Quantitative yield; colorless oil. Found: C, 68.45; H, 5.99 %, M+, 356. chromatographic column, isochroman 1f was isolated. Yield: 83%;
C20H20O6 requires C, 67.41; H, 5.66%, M, 356. νmax/cm-1: 3010, 2964, colorless oil. Found: C, 77.62; H, 6.25 %, M+, 282. C18H18O3 requires
2850, 1760 (acetate CO stretch), 1610, 1509, 1454, 1256, 1180, C, 76.57; H, 6.43; %; M, 282. νmax/cm-1: 3083, 3026, 2958, 2859,
1091. 1H-NMR (CDCl3, 400 MHz) : 7.29 (d, 2H, J = 8.5 Hz, Ph-H), 1490, 1386, 1240, 1095, 981, 856. 1H-NMR (200 MHz, CDCl3)
δ δ:
7.05 (d, 2H, J = 8.5 Hz, Ph-H), 6.72 (s, 1H, Ph-H), 6.41 (s, 1H, Ph-H), 7.35-7.28 (m, 5H, Ph-H), 6.52 (s, 1H, s, Ph-H), 6.11 (s, 1H, Ph-H), 5.60
5.63 (s, 1H, CH), 4.24-4.14 (m, 1H, CH), 3.94-3.82 (m, 1H, CH), 3.80 (s, 1H, CH), 4.17- 4.09 (m, 1H, CH), 3.94-3.80 (m, 1H, CH), 3.12-3.00
(s, 3H, OCH3), 3.11-3.02 (m, 1H, CH), 2.76-2.68 (m, 1H, CH), 2.27 (s, (m, 1H, CH), 2.70-2.42 (m, 1H, CH), 1.62 (s, 6H, 2xCH3). 13C-NMR
3H, CH3), 2.20 (s, 3H, CH3). 13C-NMR (CDCl3, 400 MHz)
δ: 169.3, (200 MHz, CDCl3) δ: 146.3, 145.8, 142.3, 129.7, 128.8, 128.4, 128.0,
169.1, 150.5, 149.8, 139.3, 137.9, 132.5, 129.9 (2C), 129.3, 121.5 126.3, 117.6, 108.1, 106.6, 79.7, 63.9, 28.8, 25.8. GC/MS (m/z, %):
(2C), 121.1, 112.,3, 78.4, 63.8, 55.9, 28.7, 21.1, 20.6. GC/MS 282 (M+, 100), 267 (52), 252 (42).
(m/z, %): 356 (M+, 20), 314 (80), 244 (100), 178 (80).
6-Methoxy-1-(4’-methoxyphenyl)isochroman-7-yl acetate
(1c). Oxidation of 2,4,6-trichlorophenol (8) and 4-methoxybenzyl
Quantitative yield; colorless oil. Found: C, 69.82; H, 6.04 %; M+, 328. alcohol (9) with the T. villosa laccase and laccase/HBT system. The
C19H20O5 requires C, 69.50; H, 6.14 %; M, 328. νmax/cm-1: 3008, 2946, oxidation reactions were performed in air at room temperature in
2850, 1756 (acetate CO stretch), 1612, 1510, 1455, 1252, 1178, magnetically stirred sodium acetate buffer (0.1 M, pH 4.7) or
1090. 1H-NMR (CDCl3, 400 MHz)
6.85 (d, 2H, J = 8.7 Hz, Ph-H), 6.73 (s, 1H, Ph-H), 6.41 (s, 1H, Ph-H), acetate buffer (0.1 M, pH 4.7)/DMC 5/1 (v/v). Compounds 8 ( 90
5.59 (s, 1H, CH), 4.19-4.10 (m, 1H, CH), 3.94-3.81 (m, 1H, CH), 3.80 mol) and 9 (60 mol) were dissolved in 3.0 mL of the appropriate
(s, 3H, OCH3), 3.76 (s, 3H, OCH3), 3.14-3.01 (m, 1H, CH), 2.78-2.67 reaction medium followed by addition of laccase (10 U); HBT (22
(m, 1H, CH), 2.20 (s, 3H, CH3). 13C-NMR (CDCl3, 400 MHz)
: 169.0, mol) was added only in the presence of 9. After 24 h, the internal
159.6, 149.7, 137.9, 134.2, 132.5, 130.2, 121.1, 113.9, 112.3, 78.7, standard was introduced in the reaction mixtures, respectively 1-
63.7, 55.9, 55.2, 28.8, 20.5. GC/MS (m/z, %): 328 (M+, 64), 286 (74), bromonaphthalene (29
mol) for compound 8 and 4’-methoxy-
δ: 7.21 (d, 2H, J = 8.7 Hz, Ph-H), sodium acetate buffer (0.1 M, pH 4.7)/DMC 10/1 (v/v) or sodium
ꢀ
ꢀ
δ
ꢀ
ꢀ
258 (87), 225 (33), 178 (61), 135 (100).
acetophenone (53 μmol) for compound 9. The crudes were
1-(4’-Acetoxy-3’-methoxyphenyl)-6-methoxyisochroman-7-yl-
extracted with ethyl acetate; finally, the organic phases were
acetate (1d). Quantitative yield; colorless oil. Found: C, 66.32; H, washed with a saturated solution of NaCl and dried over Na2SO4.
5.52 %; M+, 386. C21H22O7 requires C, 65.28; H, 5.74 %; M, 386. The yield of the oxidation reactions were determined by GC analysis
νmax/cm-1: 3010, 2974, 2843, 1766 (acetate CO stretch), 1608, 1506, with the internal standard method; suitable response factors were
1
1455, 1259, 1197, 1093. H-NMR (CDCl3, 400 MHz)
δ
: 7.24-7.03 (m, determined from authentic products.
3H, Ph-H), 6.78 (s, 1H, Ph-H), 6.44 (s, 1H, Ph-H), 5.59 (s, 1H, CH),
4.24-4.09 (m, 1H, CH), 3.94-3.82 (m, 1H, CH), 3.81 (s, 3H, OCH3), Oxidation of 1-aryl-isochromans with the T. villosa laccase/HBT
3.74 (s, 3H, OCH3), 3.12-2.99 (m, 1H, CH), 2.79-2.67 (m, 1H, CH), system. The reaction was performed in air at room temperature
2.24 (s, 3H, CH3), 2.14 (s, 3H, CH3). 13C-NMR (CDCl3, 400 MHz)
δ
:
under stirring for 24 h. The suitable substrate (0.1 mmol) was
169.1, 168.9, 151.8, 149.9, 140.5, 139.7, 132.4, 129.1, 122.5, 121.3, dissolved in 2.0 mL of reaction medium [sodium acetate buffer (0.05
121.1, 112.7, 112.3, 78.8, 63.8, 55.9, 28.6, 20.6, 20.5. GC/MS M, pH 4.7)/1,4-dioxane 1:1 (v/v) or sodium acetate buffer/DMC 5:1
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