Metal-free one-pot oxidative conversion of benzylic alcohols and benzylic halides into aromatic amides with molecular iodine in aq ammonia, and hydrogen peroxide

Article abstract of DOI:10.1016/j.tetlet.2010.06.051

Various primary alcohols, particularly benzylic alcohols, could be converted into the corresponding aromatic amides in good yields in a one-pot manner by treatment with molecular iodine in aq. NH₃, followed by reaction with ～30% aq H₂O₂. Similarly, various benzylic halides could be also converted into the corresponding aromatic amides in good yields in a one-pot manner by treatment with molecular iodine in aq NH₃, followed by reaction with ～30% aq H₂O ₂. The present reactions involve the metal-free one-pot oxidative conversion of benzylic alcohols and benzylic halides into the corresponding aromatic amides, respectively.

Full text of DOI:10.1016/j.tetlet.2010.06.051

Tetrahedron Letters 51 (2010) 4378–4381
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Tetrahedron Letters
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Metal-free one-pot oxidative conversion of benzylic alcohols and benzylic
halides into aromatic amides with molecular iodine in aq ammonia, and
hydrogen peroxide
*
Ryosuke Ohmura, Misato Takahata, Hideo Togo
Graduate School of Science, Chiba University, Yayoi-cho 1-33, Inage-ku, Chiba 263 8522, Japan
a r t i c l e i n f o
a b s t r a c t
Article history:
Various primary alcohols, particularly benzylic alcohols, could be converted into the corresponding aro-
matic amides in good yields in a one-pot manner by treatment with molecular iodine in aq. NH3, followed
by reaction with ꢀ30% aq H2O2. Similarly, various benzylic halides could be also converted into the cor-
responding aromatic amides in good yields in a one-pot manner by treatment with molecular iodine in aq
NH3, followed by reaction with ꢀ30% aq H2O2. The present reactions involve the metal-free one-pot oxi-
dative conversion of benzylic alcohols and benzylic halides into the corresponding aromatic amides,
respectively.
Received 21 May 2010
Revised 8 June 2010
Accepted 11 June 2010
Available online 16 June 2010
Ó 2010 Elsevier Ltd. All rights reserved.
Aromatic amides are one of the most important functional
groups in organic chemistry and pharmaceuticals, some examples
of which are Arotinolol hydrochloride (anti-hypertensive), Labeta-
lol hydrochloride (anti-hypertensive), Frovatriptan (migraine
headache depressant), Exalamide (antifungal), and polymers.1
Generally, aromatic amides are prepared from aroyl halides with
aq NH3 or amines (the Schotten–Baumann reaction), and aromatic
carboxylic acids with amines using dehydration reagents such as
TsCl/Py, Ph3P/CX4 (X = Cl, Br), and Ph3P/(PyS)2, N-methyl-2-chloro-
pyridinium salt.2 As alternative practical methods, the Schmidt
reaction of ketones with azides3 and the Beckmann rearrangement
of oximes derived from ketones4 are known. On the other hand,
studies of the oxidative conversion of aldehydes into amides and
the oxidative conversion of primary alcohols into amides are lim-
ited in spite of the efficiency of these approaches. The former reac-
tion includes the treatment of aldehydes with molecular iodine in
aq NH3, followed by the reaction with 33% aq H2O2,5a the treatment
of aromatic aldehydes with KI-tBuOOH,5b the treatment of alde-
hydes with PhI = NTs in the presence of a catalytic amount of Ru-
porphyrin,5c the treatment of aldehydes with secondary amines
in the presence of Rh catalyst,5d the treatment of aldehydes with
primary amines in the presence of CuI–AgIO3 catalyst,5e the treat-
ment of aromatic aldehydes with secondary amines in the pres-
benzylic alcohols into the corresponding aromatic amides,6a–c
and the initial oxidation of benzylic alcohols to aldehydes with
iridium catalyst, [Ir(Cp)Cl2]2 and CsCO3, followed by the treatment
with hydroxylamine, to provide aromatic amides.6d Moreover, the
oxidative amidation of alcohols with amine proceeds efficiently in
the presence of catalytic amounts of Ru(COD)Cl2 with 1,3-diisopro-
pylimidazolium chloride, tricyclohexylphosphine and BuOK,6e and
in a Ru-PNN-catalyzed system,6f in a [Ru(p-cymene)Cl2]2-catalyzed
system with bis(2-diphenylphosphinophenyl)ether,6g and by treat-
ment of aminoalcohols with Ru catalyst, to provide lactams.6h
However, a majority of those approaches require metal-based
oxidizing agents. Thus, a metal-free, environmentally benign, eco-
nomical, and simple oxidation approach is desired.
Here, as part of our study of molecular iodine for organic syn-
thesis,7 we would like to report a metal-free one-pot oxidative con-
version of benzylic alcohols and benzylic halides into the
corresponding aromatic amides, respectively, with molecular io-
dine in aq NH3, followed by the treatment with ꢀ30% aq H2O2.
At first, the one-pot oxidative conversion of benzylic alcohols
into the corresponding amides was studied as follows.8 A mixture
of 4-methylbenzyl alcohol and molecular iodine in aq NH3
(28–30%) was warmed for 2 h at 60 °C. Then, the reaction mixture
was cooled to 0 °C and aq NH3 was added again to the mixture.
Finally, ꢀ30% aq H2O2 was added dropwise to the reaction mixture
via a dropping funnel. After being stirred for 2 h at rt, the mixture
was poured into aq saturated Na2SO3 and then extracted with
CHCl3 to provide 4-methylbenzamide in 91% yield, as shown in
Table 1 (entry 1). Based on these conditions, other benzylic alcohols,
such as p-chlorobenzyl alcohol, p-methoxybenzyl alcohol, benzyl
alcohol, p-nitrobenzyl alcohol, and m-nitrobenzyl alcohol, were
treated under the same conditions to provide the corresponding
t
ence of BuOOH5f and the treatment of aromatic aldehydes with
primary amines in the presence of (diacetoxy)iodobenzene5g to
provide the corresponding amides. The latter reaction utilizes a
manganese(IV) dioxide-sodium cyanide system in a THF solution
containing ammonia or primary amines for the conversion of
* Corresponding author. Tel.: +81 43 290 2792; fax: +81 43 290 2874.
E-mail address: togo@faculty.chiba-u.jp (H. Togo).
0040-4039/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tetlet.2010.06.051

R. Ohmura et al. / Tetrahedron Letters 51 (2010) 4378–4381
4379
Table 1
Then, the reaction mixture was cooled to 0 °C, aq NH3 was added
again, and ꢀ30% aq H2O2 was slowly added dropwise via a drop-
ping funnel. After being stirred for 2 h at rt, the reaction mixture
was poured into aq saturated Na2SO3 and the whole was extracted
with CHCl3 to give 4-methylbenzamide in 81% yield, as shown in
Table 2 (entry 1). The same treatment of 4-methylbenzyl bromide
and 4-methylbenzyl iodide gave 4-methylbenzamide in good
yields, respectively (entries 2 and 3). Other benzylic chlorides, bro-
mides, and iodides could be also converted into the corresponding
amides in good yields (entries 4–20). However, the same treatment
of alkyl halides provided the corresponding amides in low yields,
together with the starting alkyl halides and amines.
A plausible reaction mechanism for the formation of aromatic
amide from benzylic alcohols and benzylic halides is shown in
Scheme 1. Here, the addition of molecular iodine to a solution of
p-tolualdehyde in aq NH3 induced the rapid formation of p-tolunit-
rile at rt, and the subsequent treatment of the reaction mixture
with ꢀ30% aq H2O2 provided p-toluamide in high yield at rt, as
shown in Scheme 2. The addition of ꢀ30% aq H2O2 with a dropping
funnel to a mixture of p-tolunitrile in aq NH3 in the presence of KI
smoothly gave p-toluamide in high yield at rt. Once the imine was
formed from the reaction of aldehyde with ammonia or the oxida-
Metal-free one-pot oxidative conversion of benzylic alcohols into amides with I2 in
aq NH3, followed by treatment with H2O2
1) aq. NH3, I2 (3.0 equiv)
60°C, Time.
R
CONH2
R
CH2OH
2) aq. NH3, aq. H2O2
0°C ∼ r.t., 2 h
Entry
R–
Time (h)
Yield (%)
91
1
2
3
4
5
2
2
2
2
3
CH3
Cl
93
94
CH3O
82
70
O2N
6
7
3
3
85
87
O2N
N
Table 2
Metal-free one-pot oxidative conversion of benzylic halides into aromatic amides
with I2 in aq NH3, followed by treatment with H2O2
CH3O
CH3O
CH3O
8
2
53 (39)a
1) aq. NH3, I2 (3.0 equiv)
60°C 4 h
S
Ar CH2X
Ar CONH2
9
3
62 (12)a
63
2) aq. NH3, aq. H2O2
0°C ∼ r.t.,Time
10
2b
Entry
Ar–
Time (h)
Yield (%)
11
12
3b
88
81
1
2
3
2
2
2
2
2
81
72
69
CH3
X = Cl
X = Br
X = I
4
N
Ts
13
14
15
24
6
43 (37)a
78
4
5
6
93
98
99
X = Cl
X = Br
X = I
CH3(CH2)4–
8
92
16
6
61 (30)a
7
8
9
67
69
66
X = Cl
X = Br
X = I
F
a
Yield of nitrile.
Two times of aq NH3 and I2 were used.
b
10
11
12
75
84
73
X = Cl
X = Br
X = I
Cl
Br
amides in good yields (entries 2–6). The yields with electron-rich
alcohols, such as 3,4,5-trimethoxybenzyl alcohol and 2-(hydroxy-
methyl)thiophene, were moderate, due to the less reactivity of the
formed aromatic nitriles against peroxide nucleophile (entries 8
and 9). The same treatment of 1,3- and 1,4-bis(hydroxymethyl)ben-
zenes gave the corresponding benzenediamides in good yields
(entries 10, 11). Heteroaromatics, such as 2-(hydroxymethyl)thio-
phene and 3-hydroxymethyl-1-tosylindole, provided the corre-
sponding amides in good yields under the same conditions
(entries 9 and 12). Moreover, the same treatment of primary alco-
hols, such as 1-hexanol, cyclohexylmethanol, and 1-adamantyl-
methanol, also provided the corresponding amides in good yields,
respectively (entries 14–16).
13
14
15
81
73
89
X = Cl
X = Br
X = I
16
17
2
2
85
92
X = Cl
X = Br
CH3O
O2N
18
19
20
86
93
82
X = Cl
X = Br
X = I
Then, the oxidative one-pot conversion of benzylic halides into
amides was studied as follows.9 A mixture of 4-methylbenzyl chlo-
ride and molecular iodine in aq NH3 was warmed for 4 h at 60 °C.

4380
R. Ohmura et al. / Tetrahedron Letters 51 (2010) 4378–4381
aq. NH3
aq. H2O2
Acknowledgments
I2, aq. NH3
R
R
R
CH2OH
R
R
CONH2
Financial support in the form of a Grant-in-Aid for Scientific Re-
search (No. 20550033) from the Ministry of Education, Culture,
Sports, Science, and Technology in Japan and Iodine Research Pro-
ject in Chiba University is gratefully acknowledged.
60°C
0°C ∼ r.t., 2h
I2
(-HI)
(-HOI)
+
I
C
O
NH2
OH
I-
O
CH
H
References and notes
H2O2
(-HI)
1. (a) Humphrey, J. M.; Chamberlin, A. R. Chem. Rev. 1997, 97, 2243; (b) Kleeman,
A.; Engel, J. Pharmaceutical Substances; Syntheses, Patents, Applications, 4th ed.;
Thieme: Stuttgart, 2001; (c) Bode, J. W. Curr. Opin. Drug Discov. Dev. 2006, 9,
765; (d) Cupid, T.; Tulla-Puche, J.; Spengler, J.; Albericio, F. Curr. Opin. Drug
Discov. Dev. 2007, 10, 768.
2. (a) Larock, R. C. Comprehensive Organic Transformations; Wiley-VCH: Weinheim,
1999; Recent reviews: (b) Han, S.-Y.; Kim, Y.-A. Tetrahedron 2004, 60, 2447; (c)
Montalbetti, C. A. G. N.; Falque, V. Tetrahedron 2005, 61, 10827.
I-
R
N
C
CH=O
NH3
(-HI)
(-H2O)
CH=NH
I
I2
(-HI)
R
C
H
R
R
N
3. (a) Schmidt, R. F. Ber. 1924, 57, 704; (b) Lang, S.; Murphy, J. A. Chem. Soc. Rev.
2006, 35, 146.
4. (a) Bechmann, E. Ber. 1886, 19, 988; (b) Beckmann, E. Ber. 1887, 20, 1507; (c)
Owston, N. A.; Parker, A. J.; Williams, J. M. J. Org. Lett. 2007, 9, 3599.
5. (a) Shie, J.; Fang, J. J. Org. Chem. 2003, 68, 1158; (b) Reddy, K. R.; Maheswari, C.
U.; Venkateshwar, M.; Prashanthi, S.; Kantam, M. L. Tetrahedron 2009, 50, 2050;
(c) Chang, J. W. W.; Chan, P. W. H. Angew. Chem., Int. Ed. 2008, 47, 1138; (d)
Tillack, A.; Rudloff, I.; Beller, M. Eur. J. Org. Chem. 2001, 523; (e) Yoo, W.; Li, C. J.
Am. Chem. Soc. 2006, 128, 13064; (f) Ekoue-Kovi, K.; Wolf, C. Org. Lett. 2007, 9,
3429; (g) Fang, C.; Qian, W.; Bao, W. Synlett 2008, 2529.
I
NH
CH
H
I2
(-HI)
6. (a) Gilman, N. W. J. Chem. Soc., Chem. Commun. 1971, 733; (b) Foot, J. S.; Kanno,
H.; Giblin, G. M. P.; Taylor, R. J. K. Synlett 2002, 1293; (c) Foot, J. S.; Kanno, H.;
Giblin, G. M. P.; Taylor, R. J. K. Synthesis 2003, 1055; (d) Owston, N. A.; Parker, A.
J.; Williams, J. M. J. Org. Lett. 2007, 9, 73; (e) Nordstrom, L. U.; Vogt, H.; Madsen,
R. J. Am. Chem. Soc. 2008, 130, 17672; (f) Gunanathan, C.; Ben-David, Y.;
Milstein, D. Science 2007, 317, 790; (g) Watson, A. J. A.; Maxwell, A. C.;
Williams, J. M. J. Org. Lett. 2009, 11, 2667; (h) Naota, T.; Murahashi, S. Synlett
1991, 693.
R
R
CH2NH2
NH3
(-NH4X)
CH2X
7. Reviews: (a) Togo, H.; Iida, S. Synlett 2006, 2159; (b) Togo, H. J. Synth. Org. Chem.
2008, 66, 652; Papers: (c) Mori, N.; Togo, H. Synlett 2004, 880; (d) Mori, N.;
Togo, H. Tetrahedron 2005, 61, 5915; (e) Ishihara, M.; Togo, H. Synlett 2006, 227;
(f) Ishihara, M.; Togo, H. Tetrahedron 2007, 63, 1474; (g) Iida, S.; Togo, H.
Tetrahedron 2007, 63, 8274; (h) Iida, S.; Ohmura, R.; Togo, H. Tetrahedron 2009,
65, 6257; (i) Ushijima, S.; Togo, H. Synlett 2010, 1067.
Scheme 1. Plausible reaction pathway.
1) I2 (1.5 equiv.)
8. Typical procedure for the preparation of aromatic amides from benzylic alcohols:
To a mixture of 4-methylbenzyl alcohol (122.2 mg, 1.0 mmol) and aq NH3
(3 mL, ca. 28%) was added I2 (761.4 mg, 3 mmol) at rt under empty balloon. The
mixture was stirred for 2 h at 60 °C. Then, the reaction mixture was cooled to
0 °C, aq NH3 (10 mL) was added again to the mixture, and aq H2O2 (10 mL, ca.
30%) was slowly added to the reaction mixture via a dropping funnel. After the
reaction mixture was stirred for 2 h at rt, it was poured into aq satd. Na2SO3
(3 mL), and was extracted with CHCl3 (20 mL Â 3). The organic layer was
washed with brine and dried over Na2SO4. After removal of the solvent, 4-
methylbenzamide was obtained in 91% yield in an almost pure state. If
necessary, the amide was purified by flash column chromatography on silica
gel (eluent: AcOEt) as a colorless solid.
aq. NH3, r.t., 0.5 h
CHO
CH3
2) aq. H2O2, aq. NH3,
0°C ∼ r.t., 2h
CH3
CONH2
97%
KI (3.0 equiv.)
aq. H2O2, aq. NH3,
CH3
CN
4-Methylbenzamide: Mp 160–161 °C (commercial, mp 161–163 °C); IR (Nujol):
0°C ∼ r.t., 2h
1618, 1661, 3177, 3345 cmÀ1 1H NMR (CDCl3, TMS) d = 2.40 (s, 3H), 5.97 (br s,
;
2H, –NH), 7.25 (d, J = 8.1 Hz, 2H), 7.69 (d, J = 8.1 Hz, 2H).
CH3
CONH2
9. Typical procedure for the preparation of aromatic amides from benzylic halides: To
a mixture of benzyl bromide (171.1 mg, 1.0 mmol) and aq NH3 (3 mL, ca. 28%)
was added I2 (761.4 mg, 3 mmol) at rt under an empty balloon. The mixture
was stirred for 4 h at 60 °C. Then, the reaction mixture was cooled to 0 °C, aq
NH3 (10 mL) was added again to the mixture, and aq H2O2 (10 mL, ca. 30%) was
slowly added to the mixture via a dropping funnel. After the reaction mixture
was stirred for 2 h at rt, it was poured into aq satd. Na2SO3 (3 mL), and was
extracted with CHCl3 (15 mL Â 3). The organic layer was washed with brine
and dried over Na2SO4. After removal of the solvent, benzamide was obtained
in 98% yield in an almost pure state. If necessary, the amide was purified by
flash column chromatography on silica gel (eluent: AcOEt) as a colorless solid.
Benzamide: Mp 123.3–125.5 °C (commercial, mp 128 °C); IR (Nüjol): 1624,
93%
Scheme 2.
tion of primary amine with molecular iodine, nitrile is smoothly
formed via the HI-elimination of N-iodoimine. The reaction of ni-
trile with ꢀ30% aq H2O2 in the presence of iodide in aq NH3, which
works as a reducing agent of peroxide, generated the amide.
In conclusion, benzylic alcohols could be converted into the cor-
responding aromatic amides in good yields in a one-pot manner by
the treatment with molecular iodine in aq NH3, followed by the
reaction with ꢀ30% aq H2O2. Similarly, benzylic halides could be
also converted into the corresponding aromatic amides in good
yields in a one-pot manner with the same procedure. The present
reactions involve the metal-free one-pot oxidative conversion of
benzylic alcohols and benzylic halides into the corresponding aro-
matic amides, respectively, although excess amounts of aq NH3
and ꢀ30% aq H2O2 are required. Further study in the present reac-
tion system is underway in this laboratory.
1655, 3169, 3364 cmÀ1 1H NMR (500 MHz, CDCl3) d = 7.42 (t, J = 7.8 Hz, 2H),
;
7.55 (t, J = 7.8 Hz, 1H), 7.82 (d, J = 7.8 Hz, 2H).
4-Chlorobenzamide: Mp 178.1–180.2 °C (commercial, mp 179 °C); IR (Nüjol):
1620, 1654, 3178, 3365 cmÀ1 1H NMR (400 MHz, DMSO-d6) d = 7.46 (s, 1H,
;
–NH), 7.53 (d, J = 8.6 Hz, 2H), 7.90 (d, J = 8.6 Hz, 2H), 8.05 (s, 1H, –NH).
4-Methoxybenzamide: Mp 165.8–166.4 °C (commercial, mp 166 °C); IR (Nujol):
1618, 1645, 3168, 3389 cmÀ1 1H NMR (400 MHz, DMSO-d6) d = 3.81 (s, 3H),
;
6.98 (d, J = 8.6 Hz, 2H), 7.19 (br s, 1H, –NH), 7.83 (br s, 1H, –NH), 7.85 (d,
J = 8.6 Hz, 2H).
4-Nitrobenzamide: Mp 199.3–202.0 °C (commercial, mp 203 °C); IR (Nujol):
1595, 1677, 3162, 3476 cmÀ1 1H NMR (500 MHz, DMSO-d6) d = 7.73 (br s, 1H,
;
–NH), 8.11 (d, J = 8.4 Hz, 2H), 8.30 (br s, 1H, –NH), 8.31 (d, J = 8.4 Hz, 2H).
2,5-Dimethylbenzamide: Mp 182.2–183.0 °C (lit.10 mp 185–186 °C); IR (Nujol):
1605, 1650, 3177, 3359 cmÀ1 1H NMR (500 MHz, CDCl3) d = 2.33 (s, 3H), 2.45
;
(s, 3H), 7.12–7.16 (m, 2H), 7.28 (s, 1H).

R. Ohmura et al. / Tetrahedron Letters 51 (2010) 4378–4381
4381
3,4,5-Trimethoxybenzamide: Mp 176.6–178.1 °C (commercial, mp 180 °C); IR
3H), 1.38–1.44 (m, 2H), 1.70 (m, 1H), 1.79–1.82 (m, 2H), 1.89–1.92 (m, 2H),
2.11–2.18 (m, 1H).
(Nujol): 1618, 1661, 3185, 3359 cmÀ1
9H), 7.05 (s, 2H).
;
1H NMR (400 MHz, CDCl3) d = 3.92 (s,
1-Adamantanecarboxamide: Mp 185.5–191.7 °C (commercial, mp 188 °C); IR
2-Thiophenecarboxamide: Mp 179.1–180.2 °C (commercial, mp 182 °C); IR
(Nujol): 1635, 3422, 3512 cmÀ1 1H NMR (400 MHz, CDCl3) d = 1.70–1.76 (m,
;
(Nujol): 1607, 1650, 3170, 3361 cmÀ1 1H NMR (400 MHz, DMSO-d6) d = 7.31
;
6H), 1.84–1.95 (m, 9H), 5.66 (br s, 2H, –NH).
(t, J = 4.3 Hz, 1H), 7.38 (br s, 1H, –NH), 7.73 (d, J = 4.1 Hz, 1H), 7.74 (d, J = 4.1 Hz,
1H), 7.97 (br s, 1H, –NH).
3-Nitrobenzamide: Mp 147.0–150.5 °C (commercial, mp 143 °C); IR (Nujol):
1624, 1690, 3176, 3325 cmÀ1 1H NMR (500 MHz, DMSO-d6, 25 °C): d = 7.76 (s,
;
Terephthalamide: Mp >250 °C (lit.11 mp 320–323 °C); IR (Nujol): 1621, 1661,
1H, –NH), 7.84 (t, J = 7.9 Hz, 1H), 8.37 (d, J = 7.9 Hz, 1H), 8.40 (s, 1H, –NH), 8.44
(d, J = 7.9 Hz, 1H), 8.75 (s, 1H).
3166, 3360 cmÀ1 1H NMR (400 MHz, DMSO-d6) d = 8.42 (br s, 2H, –NH), 8.84
;
(s, 4H), 9.01 (br s, 2H, –NH).
Isophthalamide: Mp >250 °C (lit.12 mp 286 °C); IR (Nujol): 1626, 1658, 3153,
3-Phenylpropionamide: Mp 96.1–97.6 °C (commercial, mp 101 °C); IR (Nujol):
3362 cmÀ1 1H NMR (400 MHz, DMSO-d6, 25 °C): d = 7.48 (s, 2H, –NH), 7.54 (t,
;
1626, 1649, 3182, 3389 cmÀ1
;
1H NMR (400 MHz, CDCl3) d = 2.54 (t, J = 15.5 Hz,
J = 7.8 Hz, 1H), 8.02 (d, J = 7.8 Hz, 2H), 8.21 (s, 2H, –NH), 8.52 (s, 1H).
10. Chakraborty, D. P.; Mandal, A. K.; Roy, Swapan K. Synthesis 1981, 977.
11. Theodorou, V.; Karkatsoulis, A.; Kinigopoulou, M.; Ragoussis, V.; Skobridis, K.
Arkivoc 2009, 11, 277.
2H), 2.98 (t, J = 15.5 Hz, 2H), 5.27 (br s, 2H, –NH), 7.19–7.32 (m, 5H).
Hexanamide: Mp 95.3–97.0 °C (commercial, mp 100 °C); IR (Nujol): 1632, 3191,
3358 cmÀ1 1H NMR (400 MHz, DMSO-d6) d = 0.86 (t, J = 7.0 Hz, 3H), 1.28–1.32
;
(m, 4H), 1.47 (quintet, J = 7.5 Hz, 2H), 2.02 (t, J = 7.5 Hz, 2H), 6.68 (br s, 1H,
–NH), 7.22 (br s, 1H, –NH).
12. Katritzky, A. R.; Pilarski, B.; Urogdi, L. Synthesis 1989, 949.
Cyclohexanecarboxamide: Mp 180.5–182.8 °C (commercial, mp 186–188 °C); IR
(Nujol): 1635, 3168, 3338 cmÀ1 1H NMR (400 MHz, CDCl3) d = 1.20–1.33 (m,
;