0.58 mmol) and DMF (2 cm3) gave 1a (38 mg, 44%) as an
off-white solid; mp 31–33 ЊC (lit.,17 33–35 ЊC). All other data in
agreement with literature values.17
4-Methyl-1,2,4-dithiazolidine-3,5-dione (1a)
Using the general procedure above with 1,2,4-dithiazolidine-
3,5-dione 2 (100 mg, 0.74 mmol), sodium bicarbonate (120 mg,
1.43 mmol), iodomethane (50 µL, 0.80 mmol) and acetonitrile
(1.5 cm3) gave 1a (86 mg, 78%) as an off-white solid. Data as
reported above.
4-Hexyl-1,2,4-dithiazolidine-3,5-dione (1b)
Using the general procedure above with 1-iodohexane (130 µL,
0.58 mmol), potassium 1,2,4-dithiazolidine-3,5-dione 3 (100
mg, 0.58 mmol) and DMF (2 cm3) gave 1b (83 mg, 65%) as a
brown oil (Found MHϩ (CI) 220.0475, C8H14NO2S2 requires
220.0466); νmax(thin film)/cmϪ1 2970–2780 (s) and 1654 (s);
δH (300 MHz; CDCl3) 0.88 (3H, t, J = 7, CH3), 1.21–1.72 (8H,
complex, (CH2)4) and 3.77 (2H, t, J = 7, CH2N); δC (75 MHz;
CDCl3) 14.0 (CH3), 22.45, 25.59, 27.31, 31.22 ((CH2)4), 46.5
(CH N) and 167.6 (C᎐O); m/z (CI) 220 (MHϩ, 100%), 160 (18),
4-Hexyl-1,2,4-dithiazolidine-3,5-dione (1b)
Using the general procedure above with 1,2,4-dithiazolidine-
3,5-dione 2 (100 mg, 0.74 mmol), potassium hydride (30 mg,
0.75 mmol), 1-iodohexane (130 µL, 0.88 mmol) and acetonitrile
(1.5 cm3) gave 1b (19 mg, 12%) as a brown oil. Data as reported
above.
᎐
2
136 (12), 128 (94) and 85 (32).
4-Isopropyl-1,2,4-dithiazolidine-3,5-dione (1c)
4-Isopropyl-1,2,4-dithiazolidine-3,5-dione (1c)
Using the general procedure above with 1,2,4-dithiazolidine-
3,5-dione 2 (100 mg, 0.74 mmol), potassium hydride (30 mg,
0.75 mmol), 2-iodopropane (85 µL, 0.87 mmol) and acetonitrile
(1.5 cm3) gave 1c (14 mg, 11%) as a colourless oil. Data as
reported above.
Using the general procedure above with 2-iodopropane (85 µL,
0.85 mmol), potassium 1,2,4-dithiazolidine-3,5-dione 3 (100
mg, 0.58 mmol) and acetonitrile (2 cm3) gave 1c (35 mg, 34%) as
a colourless oil (Found Mϩ (EI) 176.9918, C5H7NO2S2 requires
176.9918); νmax(thin film)/cmϪ1 3060–2960 (m), 1720 (s), 1660
(m) and 1020 (m); δH (300 MHz; CDCl3) 1.49 (6H, d, J = 7,
(CH3)2), 3.73 (1H, septet, CH) and 3.77; δC (75 MHz; CDCl3)
4-Allyl-1,2,4-dithiazolidine-3,5-dione (1f)
Using the general procedure above with 1,2,4-dithiazolidine-
3,5-dione 2 (100 mg, 0.74 mmol), sodium bicarbonate (120 mg,
1.43 mmol), allyl bromide (100 µL, 1.16 mmol) and acetonitrile
(1.5 cm3) gave 1f (117 mg, 90%) as an oil (Found Mϩ (EI)
174.9760, C5H5NO2S2 requires 174.9762); νmax(thin film)/cmϪ1
3118–2813 (w), 1721 (s), 1660 (s), 1432 (m), 1414 (m), 1354 (m),
1301 (s), 1189 (w), 1153 (w), 1096 (w), 989 (w), 943 (w), 697 (m)
and 650 (w); δH (300 MHz; CDCl3) 3.35 (2H, d, J = 6, CH2N),
22.7 ((CH ) ), 43.1 (CH) and 167.2 (C᎐O); m/z (EI) 177 (Mϩ,
᎐
3
2
12%), 135 (8), 84 (23), 70 (37), 64 (28), 49 (47) and 43 (100).
4-Benzyl-1,2,4-dithiazolidine-3,5-dione (1d)
Using the general procedure above with benzyl bromide
(100 µL, 0.84 mmol), potassium 1,2,4-dithiazolidine-3,5-dione
3 (100 mg, 0.58 mmol) and DMF (2 cm3) gave 1d (78 mg, 60%)
as an off-white solid; mp 91–93 ЊC (lit.,17 90–92 ЊC). All other
data in agreement with literature values.17 Note: an identical
reaction using acetonitrile (2 cm3) as solvent gave 1d in 57%
yield.
5.28 (1H, d, J 11, CH ᎐C), 5.33 (1H, dd, J 2.5 and 14, CH ᎐C)
᎐
᎐
2
2
and 5.82 (1H, m, CH); δC (75 MHz; CDCl3) 48.0 (CH2N), 120.2
(CH ), 129.2 (CH) and 167.1 (C᎐O); m/z (EI) 175 (Mϩ, 19%),
᎐
2
82 (73), 70 (82), 64 (100), 60 (80), 56 (69) and 54 (71). This
compound is reported in the patent literature as a solid; mp
80–81 ЊC.18 All of our analytical data, however, are consistent
with the structure as reported.
( )-2-(3,5-Dioxo-1,2,4-dithiazolidin-4-yl)propionic acid methyl
ester (1e)
Using the general procedure above with ( )-methyl 2-bromo-
propionate (96 µL, 0.86 mmol), potassium 1,2,4-dithiazolidine-
3,5-dione 3 (100 mg, 0.58 mmol) and DMF (2 cm3) gave 1e
(34 mg, 27%) as a yellow oil (Found Mϩ (EI) 220.9818,
C5H7NO4S2 requires 220.9817); νmax(thin film)/cmϪ1 3060–2960
(m), 1732 (s), 1716 (s), 1370 (m), 1340 (w), 1290 (m), 1140 (w),
1020 (w) and 980 (w); δH (300 MHz; CDCl3) 1.64 (3H, d, J = 7,
CH3), 3.77 (3H, s, CH3O) and 5.04 (1H, q, J = 7, CH); δC
(75 MHz; CDCl3) 14.0 (CH3), 53.1 (CH), 54.3 (CH3O), 166.8
(C᎐O) and 168.4 (C᎐O); m/z (EI) 221 (Mϩ, 39%), 193 (12), 162
4-Prenyl-1,2,4-dithiazolidine-3,5-dione (1g)
Using the general procedure above with 1,2,4-dithiazolidine-
3,5-dione 2 (100 mg, 0.74 mmol), sodium bicarbonate (120 mg,
1.43 mmol), prenyl bromide (100 µL, 0.87 mmol) and
acetonitrile (1.5 cm3) gave 1g (116 mg, 77%) as an oil (Found: C,
41.37; H, 4.53; N, 6.66. C7H9NO2S2 requires C, 41.38; H, 4.43;
N, 6.90%); (Found Mϩ (EI) 203.0070, C7H9NO2S2 requires
203.0075); νmax(thin film)/cmϪ1 3147–2832 (m), 1724 (m), 1662
(s), 1429 (w), 1292 (m), 1215 (s), 1130 (w) and 667 (s); δH (300
MHz; CDCl3) 1.73 (3H, s, CH3), 1.79 (3H, s, CH3), 4.35 (2H, d,
J = 7, CH2) and 5.22 (2H, br t, J = 7, CH); δC (75 MHz; CDCl3)
18.1 (CH3), 25.8 (CH3), 44.2 (CH2), 116.0 (CH), 140.0 (Me2C)
᎐
᎐
(45), 128 (37), 70 (100) and 64 (58).
Direct alkylation of 2—General procedure
and 167.5 (C᎐O); m/z (EI) 203 (Mϩ, 70%), 143 (100), 128 (65),
᎐
110 (39), 101 (49), 96 (70), 82 (54), 69 (70), 68 (82) and 64 (98).
The base (0.5–2.0 equiv.) was added to a stirred solution
of 1,2,4-dithiazolidine-3,5-dione 2 (100 mg, 0.74 mmol) in
acetonitrile (1.5 cm3) at room temperature. The alkyl halide
(1.0–1.6 equiv.) was added dropwise and after stirring at room
temperature for 16 h, the solvent was evaporated in vacuo with
adsorption of the residue onto silica gel for purification by
flash chromatography on silica gel (typically eluting with 90%
petroleum ether–10% ethyl acetate) to give the title compound.
4-Propargyl-1,2,4-dithiazolidine-3,5-dione (1h)
Using the general procedure above with 1,2,4-dithiazolidine-
3,5-dione 2 (100 mg, 0.74 mmol), sodium bicarbonate (120 mg,
1.43 mmol), propargyl bromide (100 µL, 1.12 mmol) and
acetonitrile (1.5 cm3) gave 1h (60 mg, 47%) as an oil (Found Mϩ
(EI) 172.9597, C5H3NO2S2 requires 172.9605); νmax(thin film)/
cmϪ1 3307 (w), 3160–2871 (m), 2121 (w), 1724 (m), 1668 (s),
1417 (w), 1348 (w), 1317 (w), 1306 (s), 1217 (s), 919 (w), 670 (s)
and 592 (m); δH (300 MHz; CDCl3) 3.35 (2H, d, J = 6, CH2N),
4-Benzyl-1,2,4-dithiazolidine-3,5-dione (1d)
Using the general procedure above with 1,2,4-dithiazolidine-
3,5-dione 2 (100 mg, 0.74 mmol), sodium bicarbonate (120 mg,
1.43 mmol), benzyl bromide (100 µL, 0.84 mmol) and
acetonitrile (1.5 cm3) gave 1d (160 mg, 96%) as an off-white
solid. Data as reported above.
5.28 (1H, d, J 11, CH ᎐C), 2.31 (1H, t, J 2.5, CH) and 4.50 (2H,
᎐
2
d, CH2); δC (75 MHz; CDCl3) 34.7 (CH2), 73.1 (CH), 75.2 (C)
and 166.5 (C᎐O); m/z (EI) 173 (Mϩ, 46%), 144 (42), 117 (46),
᎐
103 (100), 90 (29), 80 (56), 70 (63), 64 (61) and 52 (55).
O r g . B i o m o l . C h e m . , 2 0 0 3 , 1, 3 0 1 5 – 3 0 2 3
3020