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D. DE VITA ET AL.
N-(3-(1H-imidazol-1-yl)propyl)acetamide 5
from CH3CN. M.p.: 152–154 ꢂC (Tottoli-Buchi); 41% yield; IR m: 1658
(C ¼ O) cmꢁ1
;
1H-NMR: dH (400 MHz, DMSO-d6) 8.33 (d, J ¼ 8.9 Hz,
To a solution of 3-(1H-imidazol-1-yl)propan-1-amine (1.0 mmol)
and TEA (1.5 mmol) in 5 ml of CH2Cl2, acetyl chloride (1.5 mmol) in
5 ml of CH2Cl2 was added dropwise. After 12 h at RT, the reaction
mixture was evaporated under vacuum, the obtained residue was
treated with a saturated solution of Na2CO3, and the aqueous
solution was extracted in continuous with CHCl3 for 24 h. After
solvent evaporation, the crude residue was purified by column
chromatography on silica gel using CH2Cl2:MeOH (9:1) to give a
colourless oil. IR m: 1640 (C ¼ O) cmꢁ1; 65% yield; 1H-NMR: dH
(400 MHz, CD3OD) 7.69 (s, 1H), 7.17 (s, 1H), 6.98 (s, 1H), 4.08 (t,
J ¼ 7.0 Hz, 2H), 3.18 (t, J ¼ 7.0 Hz, 2H), 2.03–1.95 (m, 5H); 13C-NMR:
dC (100 MHz, CDCl3) 170.8, 137.1, 128.9, 119.0, 44.8, 36.6, 31.0, 23.1;
MS-ESIþ: m/z 167.87 [M þ H]þ.
2H), 8.02 (d, J ¼ 8.9 Hz, 2H), 7.73 (s, 1H), 7.21 (s, 1H), 6.99 (s,1H),
4.16 (t, J ¼ 6.9 Hz, 2H), 3.34 (t, J ¼ 6.9 Hz, 2H), 2015 (m ¼ 5,
J ¼ 6.9 Hz, 2H,); 13C-NMR: dC (100 MHz, CD3OD) 166.9, 149.6, 139.9,
137.2, 128.3, 127.8, 123.2, 119.2, 44.3, 37.0, 30.4; MS-ESIþ: m/z
274.97 [M þ H]þ.
N-(3-(1H-imidazol-1-yl)propyl)-[1,10-biphenyl]-4-carboxamide 9
To a solution of 3-(1H-imidazol-1-yl)propan-1-amine (1.0 mmol)
and TEA (1.5 mmol) in 5 ml of dry CH2Cl2, biphenyl-4-carbonyl
chloride (1.5 mmol) was added. The reaction mixture was kept
under stirring at room temperature for 48 h, and then was washed
with a saturated aqueous of Na2CO3 (3 ꢃ 5 ml). The organic layer,
dried over Na2SO4, filtered and evaporated under reduced pres-
sure. The crude residue was purified by column chromatography
on silica gel using CH2Cl2:MeOH (9:1) to give a solid that was twice
crystallised from AcOEt. M.p.: 135–136 ꢂC; 26% yield. IR m: 1639
N-(3-(1H-imidazol-1-yl)propyl)-4-fluorobenzamide 6
To a solution of 3-(1H-imidazol-1-yl)propan-1-amine (1.0 mmol)
and TEA (1.5 mmol) in 5 ml of CH2Cl2, 4-fluorobenzoyl chloride
(1.5 mmol) was added. The reaction mixture was stirred for 12 h at
RT and then washed with a saturated aqueous Na2CO3 (3 ꢃ 5 ml).
The organic layer, dried over Na2SO4, was evaporated, and the
obtained residue was purified by column chromatography on silica
gel using CH2Cl2:MeOH (8:2) to give an oil which was solidified by
treatment with petroleum ether M.p.: 70–72 ꢂC (Tottoli-buchi); 60%
(C ¼ O) cmꢁ1
;
1H-NMR: dH (400 MHz, DMSO-d6) 8.57 (bs, 1H), 7.94
(d, J ¼ 8.4 Hz, 2H), 7.78–7.72 (m, 4H), 7.67 (s, 1H), 7.51 (t, J ¼ 7.2 Hz,
2H) 7.41 (t, J ¼ 7.6 Hz, 1H), 7.22 (s, 1H), 6.90 (s, 1H), 4.03 (t,
J ¼ 6.8 Hz, 2H), 3.26 (q, J ¼ 6.0 Hz, 2H), 1.98 (m ¼5, J ¼ 6.8 Hz, 2H);
13C-NMR: dC (100 MHz, CD3OD) 168.7, 144.3, 139.8, 137.1, 132.8,
128.6, 127.8, 127.7, 127.5, 126.7, 126.6, 119.3, 44.4, 36.8, 30.7; MS-
ESIþ: m/z 306.07 [M þ H]þ.
yield. IR m: 1650 (C ¼ O) cmꢁ1
;
1H-NMR: dH (400 MHz, CD3OD)
Synthesis of 4-Nitro-N-(3-phenylpropyl)benzamide 10:
7.90–7.86 (m, 2H), 7.72 (s, 1H), 7.23–7.18 (m, 3H), 6.99 (s, 1H), 4.14
(t, J ¼ 7.0 Hz, 2H), 3.41 (t, J ¼ 7.0 Hz, 2H), 2.12 (m ¼ 5, J ¼ 7.0 Hz,
2H); 13C-NMR: dC (100 MHz, CDCl3) 167.0, 164.7 (J ¼ 250.0 Hz),
130.1, 130.4, 129.6 (J ¼ 9.1 Hz), 128.6, 119.2, 115.4 (J ¼ 21.0 Hz),
44.9, 37.1, 30.9; MS-ESIþ: m/z 247.60 [M þ H]þ.
N-(3-(1H-imidazol-1-yl)propyl)-4-(trifluoromethyl)benzamide 7
To a solution of 3-(1H-imidazol-1-yl)propan-1-amine (0.8 mmol)
and TEA (1.2 mmol) in 3 ml of CH2Cl2, 4-(trifluoromethyl)benzoyl
chloride (1.2 mmol) was added, and the mixture was kept over-
night under stirring at room temperature. The reaction mixture
was diluted with 5 ml of CH2Cl2 and washed with a saturated
aqueous NaHCO3 (5 ml). The aqueous phase was extracted with
CH2Cl2 (2 ꢃ 5 ml), the combined organic layers were dried over
Na2SO4, filtered and evaporated to give a residue that was purified
by column chromatography on silica gel using CH2Cl2:MeOH (8:2).
Compound 7 was obtained as a white solid. M.p.: 106–107 ꢂC
To a solution of 3-phenylpropan-1-amine (1.0 mmol) and TEA
(1.5 mmol) in 5 ml of dry CH2Cl2, 4-nitrobenzoyl chloride (1.5 mmol)
was added, and the mixture was kept overnight under stirring at
room temperature. The reaction mixture was washed with a satu-
rated aqueous of Na2CO3 (3 ꢃ 5 ml). The organic layer, was dried
over Na2SO4, filtered and evaporated to give a white solid that
was washed with petroleum ether and crystallised from toluene.
(Tottoli-Buchi); 80% yield; IR m: 1657 (C ¼ O) cmꢁ1
;
1H-NMR: dH
(400 MHz, DMSO-d6) 8.75 (bs, 1H), 8.04 (d, J ¼ 7.9 Hz, 2H), 7.86 (d,
J ¼ 7.9 Hz, 2H), 7.66 (s, 1H), 7.21 (s, 1H), 6.90 (s, 1H), 4.05–4.02 (m,
2H), 3.29–3.23 (m, 2H), 2.01–1.95 (m, 2H); 13C-NMR: dC (100 MHz,
CD3OD) 167.6, 137.9, 137.1, 132.7 (q, J ¼ 60.1 Hz), 127.8, 127.7,
125.1 (q, J ¼ 10.2 Hz), 122.6, 119.2, 44.3, 36.9, 30.5; MS-ESIþ: m/z
297.80 [M þ H]þ.
M.p.: 95–97 ꢂC (Tottoli-Buchi); 87% yield. IR m: 1636 (C ¼ O) cmꢁ1
;
1H-NMR dH (400 MHz, CD3OD) 8.33 (d, J ¼ 7.9 Hz, 2H), 8.01 (d,
J ¼ 7.9 Hz, 2H), 7.30–7.15 (m, 5H), 3.45 (t, J ¼ 6.9 Hz, 2H), 2.73 (t,
J ¼ 6.9 Hz, 2H), 1.98 (m ¼ 5, J ¼ 6.8 Hz, 2H); 13C-NMR: dC (100 MHz,
CD3OD) 165.29, 149.51, 141.35, 140.16, 128.73, 128.41, 128.00,
126.26, 123.73, 40.31, 33.71, 30.80; MS-ESIþ: m/z 283.07 [M þ H]þ.
N-(3-(1H-imidazol-1-yl)propyl)-4-nitrobenzamide 8
To a solution of 3-(1H-imidazol-1-yl)propan-1-amine (0.8 mmol)
and TEA (1.2 mmol) in 3 ml of dry CH2Cl2, 4-nitrobenzoyl chloride
Carbonic anhydrase assay
(1.2 mmol) was added, and the mixture was kept overnight under A stopped-flow method9 was used for assaying the CA catalysed
stirring at room temperature. The reaction mixture was then CO2 hydration activity with phenol red as indicator, working at the
diluted with 5 ml of CH2Cl2 and washed with a saturated aqueous absorbance maximum of 557 nm, following the initial rates of the
Na2CO3 (5 ml). The aqueous phase was extracted with CH2Cl2 CA-catalyzed CO2 hydration reaction for 10–100 s. For each inhibi-
(2 ꢃ 5 ml), and then the combined organic layers were dried over tor, at least six traces of the initial 5–10% of the reaction have
Na2SO4, filtered and evaporated under reduced pressure. The been used for determining the initial velocity. The uncatalyzed
crude residue was purified by chromatography on silica gel using rates were determined in the same manner and subtracted from
CH2Cl2:MeOH (9:1). The obtained yellowish solid was crystallised the total observed rates. Stock solutions of inhibitor (0.01 mM)