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V.K. Tandon et al. / European Journal of Medicinal Chemistry 56 (2012) 375e386
4.3.2. Tetraethyl 2,20,200,2000-(3,6-dioxocyclohexa-1,4-diene-1,2,4,5-
tetrayl)tetrakis(sulfanediyl) tetraacetate (8)
obtained was crystallized from ethyl acetate:hexane to give crys-
talline products (16)
Dark red crystals; mp 62e63 ꢀC; yield, 82%; IR (KBr/cmꢁ1): 1727
(pC]O of ester), 1659, 1497 (pC]O of quinone). 1H NMR (300 MHz,
4.4.1. 2,5-Dimorpholinocyclohexa-2,5-diene-1,4-dione (16a)
Green solid; mp 230e231 ꢀC; yield, 64%; IR (KBr/cmꢁ1): 1632,
CDCl3):
d
1.27 (t, J ¼ 6.0 Hz, 12H, 4ꢂ CH3), 3.83 (s, 8H, 4ꢂ CH2), 4.18
(q, J ¼ 6.0 Hz, 8H, 4ꢂ CH2) ppm; 13C NMR (75 MHz, CDCl3): 14.08
(4C), 35.00 (4C), 61.90 (4C), 144.58 (4C), 168.80 (4C), 173.45 (2C)
ppm; HRMS (ESI): MHþ calcd for C22H29O10S4 581.0643, found
581.0653.
1562 (pC]O of quinone); 1H NMR (300 MHz, CDCl3):
d 3.56 (bs, 8H,
4ꢂ CH2), 3.82 (bs, 8H, 4ꢂ CH2), 5.5 (s, 2H, quinone-H), ppm. 13C
NMR (75 MHz, CDCl3): 49.23 (4C), 66.69 (4C), 107.19 (2C), 152.50
(2C), 182.93 (2C), ppm. HRMS (ESI): MHþ calcd for C14H19N2O4,
279.1344, found, 279.1329.
4.3.3. Isopropyl-2,20,200,2000-(3,6-dioxocyclohexa-1,4-diene-1,2,4,5-
tetrayl)tetrakis(sulfanediyl)tetraacetate (9)
4.4.2. 2,5-Bis(4-methylpiperazin-1-yl)cyclohexa-2,5-diene-1,4-
dione (16b)
Red colored solid; mp 59e60 ꢀC; yield, 76%; IR (KBr/cmꢁ1): 1720
(pC]O of Ester), 1665, 1482 (pC]O of quinone); 1H NMR
Green powder; mp 210e211 ꢀC; yield, 72%; IR (KBr/cmꢁ1): 1628,
(300 MHz, CDCl3):
d
1.22 (d, J ¼ 6.0 Hz, 24H, 8ꢂ CH3), 3.76 (s, 8H, 4ꢂ
1567 (pC]O of quinone); 1H NMR (300 MHz, CDCl3):
d 2.32 (s, 6H,
CH2), 4.99 (sep, J ¼ 6.0 Hz, 4H, 4ꢂ CH) ppm. 13C NMR (75 MHz,
CDCl3): 21.88 (8C), 35.46 (4C), 69.79 (4C), 144.67 (4C), 168.50 (4C),
173.59 (2C) ppm; HRMS (ESI): MHþ calcd for C26H37O10S4, 637.1269,
found, 637.1267.
2ꢂ CH2), 2.51 (t, J ¼ 4.8 Hz, 8H, 4ꢂ CH2), 3.57 (t, J ¼ 4.8 Hz, 8H, 4ꢂ
CH2), 5.54 (s, 2H, quinone-H) ppm. 13C NMR (75 MHz, CDCl3): 46.09,
(2C), 48.83 (4C), 54.81 (4C), 106.98 (2C), 152.69 (2C), 182.83
(2C) ppm; HRMS (ESI): calcd for C16H25N4O2, 305.1977, found,
305.1977.
4.3.4. Tetramethyl-3,30,300,3000-(3,6-dioxocyclohexa-1,4-diene-
1,2,4,5-tetrayl)tetrakis(sulfanediyl)tetrapropanoate (10)
4.4.3. 2,5-Di(piperidin-1-yl)cyclohexa-2,5-diene-1,4-dione (16c)
Green powder; mp: >250 ꢀC; yield; 69%; IR (KBr/cmꢁ1): 1630,
Red solid; mp 235e238 ꢀC; yield, 83%; IR (KBr/cmꢁ1): 1738
(pC]O of ester),1665,1473 (pC]O of quinone); 1H NMR (300 MHz,
1571 (pC]O of quinone); 1H NMR (300 MHz, CDCl3):
d 1.67 (bs,
CDCl3):
d
2.70 (t, J ¼ 6.9 Hz, 8H, 4ꢂ CH2), 3.33 (t, J ¼ 6.9 Hz, 8H, 4ꢂ
12H, 6ꢂ CH2), 3.53 (bs, 8H, 4ꢂ CH2), 5.53 (s, 2H, quinone-H), ppm.
13C NMR (75 MHz, CDCl3): 24.53 (2C), 26.05 (4C), 50.54 (4C), 105.68
(2C), 153.40 (2C), 182.69 (2C), ppm. HRMS (ESI): MHþ calcd for
C16H23N2O2, 275.1759, found, 275.1748.
CH2), 3.69 (s, 12H, 4ꢂ CH3) ppm. 13C NMR (75 MHz, CDCl3): 29.36
(4C), 35.40 (4C), 52.10 (4C), 146.10 (4C), 171.97 (4C), 174.27 (2C)
ppm. HRMS (ESI): MHþ calcd for C22H29O10S4, 581.0643, found,
581.0641.
4.4.4. 2,5-Di(pyrrolidin-1-yl)cyclohexa-2,5-diene-1,4-dione (16d)
Green powder; mp > 300 ꢀC; yield, 76%; IR (KBr/cmꢁ1): 1620,
4.3.5. Tetraethyl 3,30,300,3000-(3,6-dioxocyclohexa-1,4-diene-1,2,4,5-
tetrayl)tetrakis(sulfanediyl)tetrapropanoate (11)
1557 (pC]O of quinone); 1H NMR (300 MHz, CDCl3):
d 1.90 (bs, 8H,
Brown oil; yield, 75%; IR (KBr/cmꢁ1): 1729 (pC]O of Ester),
4ꢂ CH2), 3.27 (bs, 4H, 2ꢂ CH2), 3.96 (bs, 4H, 2ꢂ CH2), 3.53 (bs, 8H,
4ꢂ CH2), 5.27 (s, 2H, quinone-H), ppm. 13C NMR (75 MHz, CDCl3):
23.83 (2C), 26.83 (2C), 50.74 (2C), 51.76 (2C), 99.96 (2C),149.98 (2C),
180.61 (2C), ppm. HRMS (ESI): MHþ calcd for C14H19N2O2. 247.1446,
found 247.1445.
1653, 1489 (pC]O of quinone); 1H NMR (300 MHz, CDCl3):
d 1.24 (t,
J ¼ 6.0 Hz, 12H, 4ꢂ CH3), 2.68 (t, J ¼ 5.4 Hz, 8H, 4ꢂ CH2), 3.32 (t,
J ¼ 6.0 Hz, 8H, 4ꢂ CH2), 4.14 (q, J ¼ 6.0 Hz, 8H, 4ꢂ CH2) ppm. 13
C
NMR (75 MHz, CDCl3): 14.10 (4C), 29.17 (4C), 35.38 (4C), 60.78 (4C),
145.88 (4C), 171.28 (4C), 174.11 (2C) ppm; HRMS (ESI): MHþ calcd
for C26H36O10S4, 636.1191, found, 636.1190.
4.4.5. 2,5-Dichloro-3,6-dimorpholinocyclohexa-2,5-diene-1,4-
dione (16e)
4.3.6. Isopropyl 3,30,300,3000-(3,6-dioxocyclohexa-1,4-diene-1,2,4,5-
tetrayl)tetrakis(sulfanediyl)tetrapropanoate (12)
Green powder; mp 205e207 ꢀC; yield, 78%; IR (KBr/cmꢁ1): 1653,
1581 (pC]O of quinone); 1H NMR (300 MHz, CDCl3):
d 3.60 (t,
Red colored solid; mp > 250 ꢀC; yield, 76%; IR (KBr/cmꢁ1): 1722
J ¼ 6.0 Hz, 8H, 4ꢂ CH2), 3.83 (t, J ¼ 6.0 Hz, 8H, 4ꢂ CH2) ppm. 13
C
(pC]O of Ester), 1668, 1485 (pC]O of quinone); 1H NMR
NMR (75 MHz, CDCl3): 52.08 (4C), 67.49 (4C), 116.33 (2C), 147.99
(2C), 175.97 (2C). HRMS (ESI): MHþ calcd for C14H17Cl2N2O4,
346.0565, found 347.0573.
(300 MHz, DMSO-d6):
d
1.67 (d, J ¼ 6.0 Hz, 24H, 8ꢂ CH3), 2.64 (t,
J ¼ 6.9 Hz, 8H 4ꢂ CH)2, 3.21 (t, J ¼ 6.9 Hz, 8H, 4ꢂ CH2), 4.88 (m, 4H,
4ꢂ CH) ppm. 13C NMR (75 MHz, DMSO-d6): 21.50 (8C), 29.04 (4C),
35.11 (4C), 67.60 (4C), 145.49 (4C), 170.71 (4C), 173.52 (2C) ppm;
HRMS (ESI): MHþ calcd for C30H45O10S4, 693.1895, found, 693.1894.
4.4.6. 2,5-Dichloro-3,6-bis(4-methylpiperazin-1-yl)cyclohexa-2,5-
diene-1,4-dione (16f)
Green powder; mp 199e201 ꢀC; yield, 86%; IR (KBr/cmꢁ1): 1652,
4.3.7. Octaethyl-2,20,200,2000-(3,6-dioxocyclohexa-1,4-diene-1,2,4,5-
tetrayl)tetrakis(sulfanediyl)tetrasuccinate (13)
1579 (pC]O of quinone); 1H NMR (300 MHz, CDCl3):
d 2.32 (s, 6H,
2ꢂ CH3), 2.55 (bs, 8H, 4ꢂ CH2), 3.60 (bs, 8H, 4ꢂ CH2) ppm. 13C NMR
(75 MHz, CDCl3): 46.25 (2C), 51.78 (4C), 55.78 (4C), 116.18 (2C),
148.53 (2C), 176.16 (2C) ppm. HRMS (ESI): MHþ calcd for
C16H23Cl2N4O2, 373.1198, found 373.1175.
Brown oil; yield, 79%; IR (KBr/cmꢁ1): 1734 (pC]O of ester) 1664,
1467 (pC]O of quinone); 1H NMR (300 MHz, CDCl3):
d 1.21e1.41
(m, 24H), 2.79e3.1 (m, 8H), 4.16e4.33 (m, 20H) ppm. HRMS (ESI):
calcd for C38H53O18S4, 924.2036, found 924.2048.
4.4.7. 2,5-Bis(4-benzylpiperazin-1-yl)-3,6-dichlorocyclohexa-2,5-
diene-1,4-dione (16g)
4.4. General procedure for synthesis and spectral data of
diaminocyclohexa-2,5-diene-1,4-diones (16)
Green powder; mp 280e281 ꢀC; yield, 82%; IR (KBr/cmꢁ1): 1653,
1580 (pC]O of quinone); 1H NMR (300 MHz, CDCl3):
d 2.45 (bs, 8H,
4ꢂ CH2), 3.56 (s, 4H, 2ꢂ CH2), 3.60 (bs, 8H, 4ꢂ CH2), 7.26e7.33 (m,
10H, AreH) ppm. 13C NMR (75 MHz, CDCl3): 51.79 (4C), 53.82 (4C),
63.07 (2C), 116.03 (2C), 127.56 (2C), 128.54 (4C), 129.43 (4C), 137.43
(2C), 148.55 (2C), 176.14 (2C) ppm. HRMS (ESI): MHþ calcd for
C28H31Cl2N4O2, 525.1824, found, 525.1858.
Amines (15) (4 eq) were added to an aqueous suspension of
surfactant (0.5 mol % LD). After stirring for 2 min chloranil (1b)
(1 eq) or benzoquinone (1a) (1 eq) and K2CO3 were added and the
reaction mixtures were stirred at r.t. for 6e7 h and the solid thus