the series R1 = MeCO > PhCO > Tos is not in agreement with their reactivity in the acylation of nucleophilic
compounds (alcohols and amines), which may be used for mild selective acylation and arylsulfonation of
polyfunctional organic compounds.
EXPERIMENTAL
The mass spectra of compounds were obtained on a Varian MAT-212 mass spectrometer with direct
insertion of samples into the ion source. The energy of the ionizing electrons was 70 eV. Monitoring of the
progress of reactions and the purity of the compounds obtained was effected by TLC on Silufol UV 254 plates in
the systems: a) chloroform–acetone, 9:1, b) acetone–chloroform, 4:1, c) benzene–dioxane, 2:1, d) ethyl acetate–
carbon tetrachloride, 1:1. Spots were detected with iodine vapor.
2,3-Indoledione 3-Oxime O-Acetate (1a) was obtained by the procedure of [1]; mp 130°C
(chloroform). Mass spectrum, m/z (I, %): 204 (3) [M]+, 162 (20), 144 (100), 116 (20), 91 (3), 90 (4), 89 (11),
65 (4), 63 (5), 62 (65), 60 (12).
2,3-Indoledione 3-Oxime O-Benzoate (1b). A solution of NaOH (2.4 g, 60 mmol) in water (20 ml) was
added dropwise to a mixture of compound 2a (8.1 g, 0.05 mol), benzoic anhydride (12.43 g, 55 mmol), and
dilute (2:1) aqueous acetone (90 ml) with stirring and cooling to -5°C. The mixture was stirred for some time,
diluted with water (100 ml), the solid filtered off, and dried. After recrystallization from chloroform, compound
1b (11.3 g, 85%) was obtained; mp 135°C, Rf 0.17 (a). Found, %: N 10.36. C15H10N2O3. Calculated, %: N 10.52.
Mass spectrum, m/z (I, %): 266 (0.4) [M]+·, 145 (11), 144 (100), 122 (68), 116 (20), 105 (4), 89 (10), 77 (45), 51
(18), 50 (10).
1-Methyl-2,3-indoledione 3-Oxime O-Acetate (1c) was obtained by the procedure of [1]; mp 154°C
(chloroform), Rf 0.38 (a). Mass spectrum, m/z (I, %): 218 (19) [M]+, 176 (100) [M-CH2CO]+, 159 (25)
[M-CH3CO2]+, 144 (3), 131 (6), 117 (3), 104 (3), 102 (3), 90 (4), 76 (4), 43 (47) [CH3CO]+.
1-Methyl-2,3-indoledione 3-Oxime O-Benzoate (1d) was obtained analogously to compound 1b from
1-methyl-2,3-indoledione 3-oxime (2b) (1.76 g, 10 mmol), benzoic anhydride (2.44 g, 11 mmol), aqueous
acetone (1:2) (70 ml), and NaOH (0.48 g, 12 mmol) in water (5 ml). Yield 2.4 g (86%); mp 178°C (chloroform),
Rf 0.54 (a). Mass spectrum, m/z (I, %): 280 (8) [M]+, 160 (6), 132 (3), 131 (6), 105 (100), 104 (3), 78 (2), 77 (9),
76 (2), 51 (5), 50 (2).
5-Bromo-2,3-indoledione 3-Oxime O-Acetate (1e) was obtained analogously to the previous
experiment from 5-bromo-2,3-indoledione 3-oxime (2c) (2.41 g, 10 mmol), acetic anhydride (1.12 g, 11 mmol),
acetone (30 ml), and NaOH (0.48 g, 12 mmol) in water (5 ml). Yield 2.7 g (95%); mp 146-147°C (DMF–
chloroform, 1:3), Rf 0.28 (b). Found, %: Br 28.16; N 9.72. C10H7BrN2O3. Calculated, %: Br 28.27; N 9.89.
2,3-Indoledione 3-Oxime O-(2-Nitrobenzene)sulfonate (5a) was obtained analogously from
compound 2a (1.62 g, 10 mmol), 2-nitrobenzenesulfonyl chloride (2.44 g, 11 mmol), acetone (30 ml), and
NaOH (0.48 g, 12 mmol) in water (5 ml). Yield 2.3 g (66%); mp 197-198°C (DMF–chloroform, 1:2), Rf 0.65 (c).
Found, %: N 12.02; S 9.09. C14H9N3O6S. Calculated, %: N 12.10; S 9.22.
1-Methyl-2,3-indoledione 3-Oxime O-Tosylate (5b) was obtained by the procedure of [1];
mp 177-178°C (ethyl acetate). Mass spectrum, m/z (I, %): 330 (19) [M]+, 159 (45) [M-TosO]+, 155 (25) [Tos]+,
144 (11) [M-TosO-CH3]+, 133 (20) [M-TosO-CN]+, 131 (15) [M-TosO-CO]+, 103 (5), 102 (8), 91 (100), 76 (5),
65 (19).
5-Bromo-2,3-indoledione 3-Oxime O-(2-Nitrobenzene)sulfonate (5c) was obtained analogously from
5-bromo-2,3-indoledione 3-oxime (2c) (2.41 g, 10 mmol), 2-nitrobenzenesulfonyl chloride (2.44 g, 11 mmol),
acetone (20 ml), and NaOH (0.48 g, 12 mmol) in water (5 ml). Yield 3.44 g, 81%); mp >250°C (DMF–
chloroform, 1:1). Found, %: N 9.69; S 7.62. C14H8BrN3O6S. Calculated, %: N 9.85; S 7.51.
102