before being filtered and the residue washed with acetonitrile to
yield the title compound 16 (15 g, 54%) as a white solid.
(C5), 144.0 (C3), 167.5 (C1). ESI-MS m/z 266.1 [M − H]−. HRMS
Calc. for [C12H12NO4S]− m/z 266.0487. Found 266.0481.
1H NMR (300 MHz, CDCl3)15 d = 1.21 (t, J = 7.1 Hz, 3H, ethyl
CH3), 4.10 (q, J = 7.1 Hz, 2H, ethyl CH2), 5.27 (ddm, J = 16.4,
7.5 Hz, 2H, H1), 6.48 (dd, J = 15.4, 4.8 Hz, 1H, H3), 6.69 (m, 1H,
H2), 7.64–7.71 (m, 6H, phenyl), 7.76–7.91 (m, 9H, phenyl).
(2E)(4E)-5-(3-Methanesulfonylaminophenyl) pentadienohydrox-
amic acid tetrahydro-2H-pyran-2-yl ester 19. To carboxylic
acid 18 (660 mg, 2.5 mmol), HOBt (500 mg, 3.7 mmol) and
EDC·HCl (570 mg, 3.0 mmol) was added 38 mL DMF under
an atmosphere of nitrogen. The resulting solution was stirred
at room temperature for 45 minutes before O-(tetrahydro-2H-
pyran-2-yl)hydroxylamine (230 mg, 2.0 mmol) was added. The
solution was then heated at 50 ◦C for 24 hours before being
cooled to room temperature and diluted with 180 mL water.
The solution was extracted with dichloromethane (3 × 100 mL)
and the organic extracts combined, washed with water, saturated
aqueous NaHCO3 and then water, dried (Na2SO4), filtered, and
the filtrate concentrated in vacuo to yield a yellow oil. Flash
chromatography (80% ethyl acetate–hexanes) yielded the title
compound 19 (520 mg, 57%) as a white solid.
(2E)(4E)-5-(3-Methanesulfonylaminophenyl)pentadienoic acid
ethyl ester 17b. To
a
chilled suspension of (trans-3-
ethoxycarbonylallyl)phosphonium bromide 16 (7.2 g, 16 mmol) in
100 mL THF was added potassium tert-butoxide (1.7 g, 15 mmol)
under an atmosphere of nitrogen. The resulting orange suspension
was stirred at room temperature for an hour before being re-
cooled to 0 ◦C. Aldehyde 15 (1.3 g, 6.0 mmol) in 30 mL THF was
then added and the suspension was stirred at 0 ◦C for 10 minutes
before being allowed to warm to room temperature. After stirring
at room temperature for 5 hours the mixture was diluted with
100 mL 1 M aqueous HCl and extracted with ethyl acetate (2 ×
80 mL, 1 × 50 mL). The organic extracts were combined, washed
with brine, dried (MgSO4), filtered, and the filtrate concentrated
in vacuo to yield an orange oil. Flash chromatography (40%
ethyl acetate–hexanes) followed by recrystallisation (ethyl acetate–
hexanes) yielded the title compound 17b (630 mg, 36%) as a white
solid together with the partially purified (2E)(4Z) isomer 17a as
an oil.
IR (nujol mull) m = 3176m, 1652m cm−1. 1H NMR (300 MHz,
DMSO) d = 1.57–1.73 (m, 6H, pyran H3, pyran H4 and pyran
H5), 3.04 (s, 3H, SO2CH3), 3.56 (m, 1H, pyran H6), 4.05 (m, 1H,
pyran H6), 4.92 (s, 1H, pyran H2), 6.11 (d, J = 14.7 Hz, 1H,
H2), 7.06 (m, 2H, H4 and H5), 7.20 (m, 1H, phenyl), 7.33 (m,
4H, H3 and phenyl). 13C NMR (75 MHz, DMSO) d = 18.3 and
24.6 and 27.8 (pyran C3, pyran C4 and pyran C5), 39.3 (SO2CH3),
61.4 (pyran C6), 101.1 (pyran C2), 118.4 and 120.1 (phenyl CH),
122.3 (C2 and phenyl CH), 127.4 (C4), 129.7 (phenyl), 137.2 (4◦
C), 138.1 (C5), 138.8 (4◦ C), 139.7 (C3), 162.7 (C1). ESI-MS m/z
389.1 [M + Na]+, 421.2 [M + MeOH + Na]+. Microanalysis Calc.
for C17H22N2O5S·H2O: C 53.11, H 6.29, N 7.29. Found C 53.12,
H 6.30, N 6.98%.
Mp 152–154 ◦C. IR (nujol mull) m = 3275m, 2854m, 1712s cm−1.
1H NMR (2E)(4E) isomer: (300 MHz, CDCl3) d = 1.32 (t, J =
7.1 Hz, 3H, ethyl CH3), 3.03 (s, 3H, SO2CH3), 4.24 (q, J = 7.1 Hz,
2H, ethyl CH2), 6.02 (d, J = 15.2 Hz, 1H, H2), 6.87 (m, 2H, H4
and H5), 7.17 (m, 1H, phenyl), 7.28 (m, 1H, phenyl), 7.35 (m,
2H, phenyl), 7.42 (ddd, J = 15.2, 7.5, 2.8 Hz, 1H, H3). 1H NMR
partially purified (2E)(4Z) isomer: (300 MHz, CDCl3) d = 1.28
(t, J = 7.1 Hz, 3H, ethyl CH3), 3.06 (s, 3H, SO2CH3), 4.20 (q,
J = 7.1 Hz, 2H, ethyl CH2), 6.06 (dm, J = 15.3 Hz, 1H, H2),
6.39 (t, J = 11.6 Hz, 1H, H4), 6.77 (d, J = 11.6 Hz, 1H, H5),
(2E)(4E)-5-(3-Methanesulfonylaminophenyl) pentadienohydrox-
amic acid 4. To a solution of protected hydroxamate 19 (400 mg,
1.1 mmol) in 18 mL of a 1 : 1 mixture of acetonitrile and methanol
was added HCl (1.0 M aqueous solution, 2.4 mL, 2.4 mmol) at
room temperature. After stirring for 6 hours the solution was
concentrated in vacuo to yield the title compound 4 (290 mg, 93%)
as a brown foam.
7.09–7.38 (m, phenyl), 7.72 (dd, J = 15.3, 11.6 Hz, 1H, H3). 13
C
NMR (75 MHz, DMSO) d = 14.1 (ethyl CH3), 39.4 (SO2CH3),
59.8 (ethyl CH2), 118.5 and 120.5 (phenyl CH), 121.4 (C2), 122.5
(phenyl CH) 126.9 (C4), 129.7 (phenyl CH) 136.9 and 139.0 (4◦ C)
140.0 (C5), 144.4 (C3), 166.1 (C1). ESI-MS m/z 294.2 [M − H]−.
HRMS Calc. for [C14H16NO4S]− m/z 294.0800. Found 294.0798.
Microanalysis Calc. for C14H17NO4S·0.2H2O: C 56.25, H 5.87, N
4.69. Found C 56.21, H 5.80, N 4.65%.
1
IR (powder) m = 1642m cm−1. H NMR (400 MHz, DMSO)
d = 3.04 (s, 3H, SO2CH3), 6.07 (d, J = 15.0 Hz, 1H, H2), 7.03 (m,
2H, H4 and H5), 7.19 (m, 1H, phenyl), 7.26 (dd, J = 15.0, 9.6 Hz,
1H, H3), 7.38 (m, 3H, phenyl), 9.78 (s, 1H, SO2NH), 10.75 (brs,
1H, CONH). 13C NMR (75 MHz, DMSO) d = 39.4 (SO2CH3),
118.3 and 120.0 and 122.3 (phenyl CH), 122.8 (C2), 127.6 (C4),
129.7 (phenyl CH), 137.3 (4◦ C), 137.4 (C5), 138.5 (C3), 138.8 (4◦
C), 162.8 (C1). ESI-MS m/z 283.3 [M + H]+, 305.2 [M + Na]+.
HRMS Calc. for [C12H15N2O4S]+ m/z 283.0753. Found 283.0748.
(2E)(4E)-5-(3-Methanesulfonylaminophenyl)pentadienoic acid
18. To a suspension of ester 17b (1.0 g, 3.4 mmol) in 11 mL
methanol was added sodium hydroxide (13 mL, 1 M aqueous
solution, 13 mmol). The resulting yellow solution was stirred at
room temperature for 1 hour before being acidified with 1 M
aqueous HCl. The resulting suspension was then extracted with
ethyl acetate (3 × 50 mL) and the extracts combined, dried
(MgSO4), filtered, and the filtrate concentrated in vacuo to yield
the crude title c◦ompound 18 (890 mg, 89%) as a pale yellow solid.
Mp 192–196 C. IR (nujol mull) m = 3265m, 2854m, 1672s cm−1.
1H NMR (300 MHz, DMSO) d = 3.05 (s, 3H, SO2CH3), 6.08 (d,
J = 15.2 Hz, 1H, H2), 7.07 (m, 2H, H4 and H5), 7.21 (m, 1H,
phenyl), 7.38 (m, 4H, H3 and phenyl), 9.80 (brs, 1H, NH), 12.29
(brs, 1H, OH). 13C NMR (75 MHz, DMSO) d = 39.4 (SO2CH3),
118.5 and 120.4 (phenyl CH), 122.4 and 122.7 (C2 and phenyl
CH), 127.2 (C4), 129.8 (phenyl CH), 137.1 and 138.9 (4◦ C), 139.3
Biology. Western blot analysis
Histones were isolated by acid extraction. Cells (5 × 106) treated
with or without agents (Oxamflatin 1, Metacept-1 2, 3a, 3b, 4)
were harvested and washed with PBS. Cells were lysed in ice-cold
lysis buffer [10 mM HEPES (pH 7.9), 1.5 mM MgCl2, 10 mM
KCl, 0.5 mM DTT, and 1.5 mM phenylmethylsulfonyl fluoride],
and 5 M H2SO4 was added. After incubation on ice for 1 h, the
suspension was centrifuged, and the supernatant was harvested,
◦
mixed with acetone at a ratio of 9 : 1, and incubated at −20 C
overnight. After centrifugation, the pellet was washed with 70%
This journal is
The Royal Society of Chemistry 2006
Org. Biomol. Chem., 2006, 4, 3778–3784 | 3783
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