A. Poso et al.
MED
3-(2-Methyl-2H-tetrazol-5-yl)phenyl cyclohexylcarbamate (9a):
This compound was prepared and worked up as described for 7b.
The isomers were separated by flash chromatography (CH3OH/
CH2Cl2, 0.5!1%) and major product was crystallized (EtOAc/
hexane) giving 9a (270 mg, 35%) as a white solid: mp 158–1608C;
1H NMR (CDCl3, 400 MHz): d=7.97(d, J=7.8 Hz, 1H), 7.93–7.90 (m,
1H), 7.47 (t, J=7.9 Hz, 1H), 7.28–7.23 (m, 1H), 7.97 (br d, J=7.8 Hz,
1H), 4.39 (s, 3H), 3.65–3.52 (m, 1H), 2.07–1.98 (m, 2H), 1.80–1.70
(m, 2H), 1.68–1.59 (m, 1H), 1.45–1.33 (m, 2H), 1.30–1.17 ppm (m,
3H); 13C NMR (CDCl3, 100 MHz): d=164.7, 153.3, 151.5, 129.8,
128.5, 123.6, 123.5, 120.1, 50.2, 39.5, 33.2, 25.4, 24.7 ppm; Anal.
calcd for C15H19N5O2: C 59.79, H 6.36, N 23.24, found: C 59.49, H
6.20, N 23.13.
and the residue was crystallized (EtOAc/CH2Cl2) to give 9h
(290 mg, 83%) as a white crystalline solid: mp 139–1418C; H NMR
1
(CDCl3, 400 MHz): d=7.60 (dt, J=7.7, 1.3 Hz, 1H), 7.53 (s, 1H) 7.37
(t, J=7.9 Hz, 1H), 7.20 (dd, J=8.2, 1.5 Hz, 1H), 5.07 (br d, J=
7.5 Hz, 1H), 3.77 (br s, 4H), 3.60–3.48 (m, 1H), 2.05–1.96 (m, 2H),
1.79–1.69 (m, 2H), 1.67–1.58 (m, 1H), 1.43–1.31 (m, 2H), 1.28–
1.13 ppm (m, 3H); 13C NMR (CD3OD, 100 MHz): d=166.7, 156.0,
152.8, 132.5, 130.4, 125.4, 125.0, 121.8, 51.7, 50.4, 34.0, 26.6,
26.1 ppm; Anal. calcd for C16H21N3O2: C 66.88, H 7.37, N 14.62,
found: C 66.54, H 7.33, N 14.27.
3-(2-Methoxyethoxymethoxy)-benzonitrile (32):[87,93] An ice-cold
solution of 3-cyanophenol (29, 1.79 g, 15 mmol, 1 equiv) and Et3N
(2.7 mL, 19.5 mmol, 1.3 equiv) in dry THF (60 mL) was treated drop-
wise with methoxyethoxymethyl chloride (2.7 mL, 24.0 mmol,
1.6 equiv) under Ar. The mixture was allowed to warm to RT and
then heated at reflux overnight. The mixture was poured into
EtOAc, washed with H2O and brine, and dried (Na2SO4). Evapora-
tion of solvent gave 32 (2.74 g, 88%) as a white solid: 1H NMR
(CDCl3, 500 MHz): d=7.39–7.34 (m, 2H), 7.30–7.27 (m, 2H), 5.28 (s,
2H), 3.83–3.81 (m, 2H), 3.56–3.54 (m, 2H), 3.37 ppm (s, 3H);
13C NMR (CDCl3, 125.1 MHz): d=157.4, 130.3, 126.6, 121.2, 119.7,
118.6, 113.3, 93.5, 71.5, 68.0, 59.0 ppm.
3-(1-Methyl-1H-tetrazol-5-yl)phenyl cyclohexylcarbamate (9b):
The minor product from preparation of 9a was crystallized (EtOAc/
hexane) giving 9b (26 mg, 3%) as a white crystalline solid: mp
1
157–1618C; H NMR (CDCl3, 400 MHz): d=7.61–7.51 (m, 3H), 7.40–
7.32 (m, 1H), 5.08–4.97 (br d, 1H), 4.19 (s, 3H), 3.64–3.51 (m, 1H),
2.10–1.97 (m, 2H), 1.82–1.70 (m, 2H), 1.69–1.57 (m, 1H), 1.46–1.33
(m, 2H), 1.32–1.14 ppm (m, 3H); 13C NMR (CDCl3, 100 MHz): d=
153.8, 153.0, 151.5, 130.3, 125.2, 124.6, 124.4, 122.1, 50.3, 35.1, 33.2,
25.4, 24.7 ppm; Anal. calcd for C15H19N5O2: C 59.79, H 6.36, N 23.24,
found: C 59.80, H 6.30, N 23.07.
3-(5-Butyl-1,2,4-oxadiazol-3-yl)phenyl
cyclohexylcarbamate
(11d): Purification by flash chromatography (EtOAc/PE) and crystal-
lization (EtOAc/hexane) gave 11 d (167 mg, 49%) as a white crystal-
line solid: mp 96.8–97.78C; H NMR (CDCl3, 500.1 MHz): d=7.75 (d,
3-(Cyclohexylcarbamoyloxy)benzoic acid (9d): Crystallization
(EtOAc/hexane) gave 9d (280 mg, 73%) as a white solid: mp 205–
2068C; 1H NMR ([D6]DMSO, 400 MHz): d=13.13 (s, 1H), 7.8387.75
(m, 2H), 7.61–7.58 (m, 1H), 7.50 (t, J=7.9 Hz, 1H), 7.38–7.34 (m,
1H), 3.40–3.27 (m, 1H), 1.89–1.79 (m, 2H), 1.76–1.66 (m, 2H), 1.61–
1.52 (m, 1H), 1.34–1.05 ppm (m, 5H); 13C NMR ([D6]DMSO,
100 MHz): d=166.6, 153.2, 151.1, 132.0, 129.6, 126.2, 125.7, 122.3,
49.8, 32.5, 25.1, 24.5 ppm; Anal. calcd for C14H17NO4: C 63.87, H
6.51, N 5.32, found: C 63.95, H 6.60, N 5.61.
1
J=7.7 Hz, 1H), 7.85–7.84 (m, 1H), 7.45 (t, J=7.9 Hz, 1H), 7.28 (d,
J=8.2 Hz, 1H), 4.93 (d, J=6.9 Hz, 1H), 3.60–3.55 (m, 1H), 2.94 (t,
J=7.6 Hz, 1H), 2.02 (br d, J=9.7 Hz, 2H), 1.88–1.82 (m, 2H), 1.76–
1.74 (m, 2H), 1.65–1.62 (m, 1H), 1.49–1.34 (m, 5H), 1.27–1.16 (m,
3H), 0.97 ppm (t, J=7.4 Hz, 3H); 13C NMR (CDCl3, 125.1 MHz): d=
180.1, 167.7, 153.3, 151.4, 129.7, 128.2, 124.4, 124.0, 120.8, 50.2,
33.2, 28.6, 26.3, 25.4, 24.7, 22.1, 13.5 ppm; Anal. calcd for
C19H25N3O3: C 66.45, H 7.34, N 12.24, found: C 66.39, H 7.41, N
12.39.
3-Hydroxybenzamide (40):[92] A solution of 3-cyanophenol (29)
(295 mg, 2.48 mmol, 1 equiv) and NaBO3·4H2O (1.15 g, 7.45 mmol,
3 equiv) in H2O (8 mL) was heated to 508C and CH3OH (14 mL) was
added until the mixture became clear. Stirring was continued at
508C for 70 h. Excess CH3OH was evaporated and the remaining
mixture was adjusted to pH 5 with concd HCl (aq). The mixture
was extracted with CH2Cl2 and EtOAc (5ꢆ15 mL). The combined or-
ganic phases were washed with brine and dried (Na2SO4). Evapora-
tion of solvent gave 40 (183 mg, 54%) as a white solid: mp 165–
1688C; 1H NMR ([D6]DMSO, 400 MHz): d=9.58 (s, 1H), 7.84 (br s,
1H), 7.29–7.20 (m, 4H), 6.89 ppm (ddd, J=7.9, 2.5, 1.0 Hz, 1H).
Dimethyl 4-hydroxyphtalate (42):[94] 3-Hydroxyphtalic acid (41,
360 mg, 2.0 mmol, 1 equiv) was dissolved in CH3OH (20 mL), and
concd H2SO4 (11 mL, 0.2 mmol, 0.1 equiv) was added to the mixture.
The mixture was refluxed for 24 h, cooled to RT, poured into satu-
rated NaHCO3 (30 mL), and most of the CH3OH was evaporated.
The mixture was extracted with EtOAc and the combined organic
phases were dried (Na2SO4), filtered and evaporated giving 42
(400 mg, 95%) as a white solid: mp 110–1118C; 1H NMR (CDCl3,
500.1 MHz): d=7.74 (d, 1H, J=8.6 Hz), 7.24 (br s, 1H), 7.01 (d, 1H,
J=2.6 Hz), 6.92 (dd, 1H, J=8.4, 2.6 Hz) 3.90 (s, 3H) 3.86 ppm (s,
3H); 13C NMR (CDCl3, 125.1 MHz): d=169.6, 167.2, 159.4, 135.6,
131.9, 121.5, 117.3, 115.3, 53.0, 52.5 ppm.
3-Formylphenyl cyclohexylcarbamate (9g): Recrystallization from
EtOAc/hexane gave 9g (2.9 g, 69%) as a white crystalline solid; mp
120–1228C; 1H NMR (CDCl3, 400 MHz); 9.92 (s, 1H), 7.71 (d, J=
7.6 Hz, 1H), 7.67–7.65 (m, 1H), 7.52 (t, J=7.8 Hz, 1H), 7.43–7.39 (m,
1H), 5.01 (br d, J=6.8 Hz, 1H), 3.63–3.51 (m, 1H), 2.09–1.98 (m,
2H), 1.81–1.71 (m, 2H), 1.68–1.59 (m, 1H), 1.45–1.32 (m, 2H), 1.30–
1.14 ppm (m, 3H); 13C NMR (CDCl3, 100 MHz): d=191.4, 153.1,
151.7, 137.6, 129.9, 127.8, 126.4, 122.4, 50.3, 33.2, 25.4, 24.7 ppm;
Anal. calcd for C14H17NO3: C 68.00, H 6.93, N 5.66, found: C 67.83, H
6.86, N 5.65.
In vitro assays
Animals and preparation of rat brain homogenate for FAAH assay:
Eight-week old male Wistar rats were used in these studies. All
animal experiments were approved by the local ethics committee.
The animals were housed with a standard 12 h lights on/off cycle
(lights on at 07:00) with water and food available ad libitum.
3-(4,5-Dihydro-1H-imidazol-2-yl)phenyl
cyclohexylcarbamate
(9h): A solution of 9g (300 mg, 1.2 mmol, 1 equiv) in CH2Cl2
(10 mL) was treated with ethane-1,2-diamine (85 mL, 1.3 mmol,
1.05 equiv) at ꢀ28C (Tbath). The mixture was stirred for 30 min and
N-bromosuccinimide (230 mg, 1.3 mmol, 1.05 equiv) was added.
The mixture was allowed to warm to RT over 1 h and evaporated
to dryness. The resulting solid was dissolved in 10% Et3N in EtOAc
and filtered through a pad of silica. The solution was concentrated
The rats were decapitated, whole brains minus cerebellum were
dissected and homogenized in one volume (v/w) of ice-cold 0.1m
potassium phosphate buffer (pH 7.4) with a Potter–Elvehjem ho-
mogenizer (Heidolph, Schwabach, Germany). The homogenate was
centrifuged at 10000 g for 20 min at 48C and the resulting super-
natant was used as a source of FAAH. The protein concentration of
226
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ChemMedChem 2010, 5, 213 – 231