Drug Evolution: Hybridization Method
Journal of Medicinal Chemistry, 2004, Vol. 47, No. 27 6981
resulting residue was purified using preparative HPLC and
David Bryant, Jonah Prevost Kirkwood, Melissa McKin-
ney, and Benedicte Patureau from Concordia Univer-
sity, Montreal, Quebec, for their technical assistance
and useful discussions. We also thank Dr. Anatoli
Koutychenko from Biomolecular NMR and Protein
Research Group, BRI for the NMR measurements. We
are grateful to the Natural Sciences and Engineering
Research Council of Canada for financial support of this
work.
transformed into acetate. tR ) 30.97 min (system 2) MS
1
[M + 1]: 230.0. H NMR (500 MHz, (CD3)2CO): δ (ppm) 1.28
(t, J ) 6.8 Hz, 3H), 3.77 (s, 3H), 4.19 (q, J ) 6.8 Hz, 2H), 5.55
(bs, 2H), 6.55 (s, 1H), 7.69 (s, 1H).
Compound 14, 4-Amino-5-chloro-N-ethyl-2-methoxy-
benzamide Acetate. To a solution of ethylamine hydrochlo-
ride (4.0 g, 50 mmol) in water (10 mL), DCM (10 mL) was
added. The aqueous phase was brought to pH 12 by adding
concentrated NaOH solution. The free amine was extracted
with DCM (3 × 10 mL), and the combined organic layers were
washed with brine and dried over sodium sulfate. 4-Amino-
5-chloro-2-methoxybenzoic acid (400 mg, 2 mmol), TBTU (650
mg), and DIEA (350 µL) were added to the DCM solution of
ethylamine, and the mixture was left overnight at room
temperature. After evaporation of the solvent, the residue was
dissolved in ethyl acetate, washed with 10% sodium carbonate,
water, and brine, and dried over sodium sulfate. After evapo-
ration, the residue was purified by preparative HPLC and
transformed into acetate. tR ) 22.73 min (system 2). MS
References
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1
[M + 1]: 229.0. H NMR (500 MHz, (CD3)2CO): δ (ppm) 1.12
(t, J ) 6.8 Hz, 3H), 3.32 (m, 2H), 3.9 (s, 3H), 5.39 (d, J ) 9.3
Hz, 2H), 6.59 (s, 1H), 7.84 (d, J ) 2.4 Hz, 1H), 7.95 (s, 1H).
Compound 15, 2-Diethylaminoethyl 4-Amino-5-chloro-
2-methoxybenzoate Acetate. 4-Amino-5-chloro-2-methoxy-
benzoic acid (400 mg, 2.0 mmol) was dissolved in toluene (20
mL) containing N,N-diethylaminoethanol (400 µL, 30 mmol)
and sulfuric acid (3 mL). The mixture was gently heated with
stirring on a water bath for 1 h and then left overnight at room
temperature. After the mixture was poured onto 10% sodium
carbonate, the organic layer was separated, and the aqeous
layer was further extracted with ethyl acetate. The combined
organic phases were washed with 10% sodium carbonate,
water, and brine and dried over sodium sulfate. After evapora-
tion, the product was purified by preparative HPLC and
transformed into acetate. tR ) 18.9 min (system 2). MS
1
[M + 1]: 301.3. H NMR (500 MHz, (CD3)2CO): δ (ppm) 1.35
(t, J ) 6.8 Hz, 6H), 3.31 (m, 6H), 3.8 (s, 3H), 4.62 (t, J ) 4.5
Hz, 2H), 5.85 (bs, 2H), 6.57 (s, 1H), 7.75 (s, 1H).
Compound 23, 2-Acetoxy-3-methylbenzamide. 2-Ac-
etoxy-3-methylbenzoic Acid. Acetic anhydride (10 mL) was
added to 3-methylsalicylic acid (4.0 g, 26 mmol), the mixture
was stirred at room temperature for 30 min, and then sulfuric
acid (0.5 mL) was added dropwise. The mixture was stirred
at room temperature until the solid dissolved completely and
was then heated on a boiling water bath for 10 min. Water
(50 mL) was added, the mixture was stirred until the disap-
pearance of the oily layer, and then it was heated for another
10 min and left to cool at room temperature. The homogeneous
mixture was treated with saturated sodium bicarbonate solu-
tion (30-50 mL) and then acidified with 3 N HCl. After the
mixture was cooled in an ice bath, a white, fluffy precipitate
formed and was filtered off to give the desired product (4.0 g),
which was used in the next step without further purification.
tR ) 5.98 min (system 1). MS [M + 1]: 195.0.
2-Acetoxy-3-methylbenzamide. To a solution of 2-ac-
etoxy-3-methylbenzoic acid (1.0 g, 5.2 mmol) in DMF (20 mL),
diisopropylcarbodiimide (0.65 g, 5.2 mmol) was added and the
mixture was stirred at room temperature for 30 min and then
treated with 3 mL 2 M NH3/ethanol (0.087 g, 5.2 mmol). The
reaction mixture was further stirred at room temperature for
3 h, treated afterward with saturated sodium carbonate
solution (30-50 mL), and extracted with ethyl acetate. The
organic phase was washed with water and brine and dried over
sodium sulfate to afford, after evaporation, the desired product,
which was purified by preparative HPLC. tR ) 9.155 min
(system 1). MS [M + 1]: 194.0. 1H NMR (500 MHz, (CD3)2-
CO): δ (ppm) 2.36 (s, 3H), 5.16 (q, J ) 6.65 Hz, 3H), 7.27 (t,
J ) 7.46, 1H), 7.61 (d, J ) 7.47 Hz, 1H), 7.83 (d, J ) 7.6 Hz,
1H), 8.00 (bs, -NH2).
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Acknowledgment. We acknowledge Drs. Piotr Ste-
fanowicz, Pierre de Macedo, and Gheorghe Roman for
their useful discussion. We thank the co-op students: