One-pot Reductive Monoalkylation of Nitro
Aryls Using Aromatic Aldehydes with H2
over Pd/SiO2
Hui Li·Zhengping Dong·Pan Wang·Fengwei Zhang·Jiantai Ma
State Key Laboratory of Applied Organic Chemistry, Lanzhou, 730000, People’s
Republic of China
College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou,
730000, People’s Republic of China
*Corresponding author. Tel/fax: +86-931-8912577.
E-mail address: majiantai@lzu.edu.cn (Jiantai Ma).
Supporting Information
Title and table of contents ………………………………………………………………..1
Experimental procedure…………………………………………………………………..2-3
Compound data……………………………………………………………………………3-5
Copies of MS spectra……………………………………………………………………...5-22
1. Experimental procedure
Reaction of nitrobenzene and benzaldehyde: optimization of the reaction conditions
Table 1 N-alkylation of nitrobenzene with benzaldehyde catalyzed by Pd/SiO2 under H2
atmosphere and various temperature a.
entry
temp. (℃)
conv. (%)
yield (%)b
1
r.t. (20)
72.
70
2
40
99
99
3
80
79
75
4
100
86
78
a
The reaction was carried out with nitrobenzene (0.5 mmol), benzaldehyde (0.75 mmol), and
Pd/SiO2 (20 mg, 15 wt %) in aqueous ethanol (5 ml) for 10 h.
b Determined by GC.
Table 2 N-alkylation of nitrobenzene with benzaldehyde catalyzed by Pd/SiO2 under H2
atmosphere and various reaction time a.
entry
time (h)
conv. (%)
yield (%)b
1
2
3
4
5
1
2
4
8
20
28
75
100
100
100
25
70
89
89
80
a
The reaction was carried out with nitrobenzene (0.5 mmol), benzaldehyde (0.75 mmol), and
Pd/SiO2 (20 mg, 15 wt %) in aqueous ethanol (5 ml) at 40 oC.
b Determined by GC-MS.
Table 3 N-alkylation of nitrobenzene with benzaldehyde catalyzed by Pd/SiO2 under H2
atmosphere and in various solventsa
entry
solvent
conv. (%)
yield (%)b
1
2
3
4
5
6
MeOH
i-PrOH
n-BuOH
i-BuOH
s-BuOH
EtOH
100
100
100
100
100
100
4
85
85
86
85
99
a
The reaction was carried out with nitrobenzene (0.5 mmol), benzaldehyde (0.75 mmol), and
Pd/SiO2 (20 mg, 15 wt %) in aqueous alcoholic solvents (5 ml) at 40 oC for 10 h.
b Determined by GC-MS
2. Compounds data
3a N-benzylaniline (Table 1, entry 1, Table 2, entry 8 and Table 3, entry 10, commercially
available)
3b N-(3, 5-dimethoxybenzyl)aniline (Table 2, entry 1). MS (EI) 243 (M+)
3c 2-methoxy-4-((phenylamino)methyl)phenol (Table 2, entry 2). MS (EI) 229 (M+)
3d N-(3,4-dimethoxybenzyl)aniline (Table 2, entry 3). MS (EI) 243 (M+)
3e N-(4-methoxybenzyl)aniline (Table 2, entry 4). MS (EI) 213 (M+)
3f 4-((phenylamino)methyl)benzene-1,3-diol (Table 1, entry 5). MS (EI) 215 (M+)
3g 3-((phenylamino)methyl)phenol (Table 1, entry 6). MS (EI) 199 (M+)
3h N-(4-chlorobenzyl)aniline (Table 1, entry 7). MS (EI) 217 (M+)
3i N-benzyl-2-methylaniline (Table 3, entry 1). MS (EI) 197 (M+)
3o N-benzyl-4-chloroaniline (Table 3, entry 7). MS (EI) 217 (M+)
3r N-ethyl-4-methylaniline (Scheme 1) MS (EI) 135 (M+)
6 N-benzylidene-4-methoxyaniline (Scheme 2) MS (EI) 211 (M+)
8a N-benzylidenenaphthalen-2-amine (Table 4, entry 1). MS (EI) 231 (M+)
9a N-benzylnaphthalen-2-amine (Table 3, entry 1). MS (EI) 233 (M+)
8b N-(4-methoxybenzylidene)naphthalene-2-amine (Table 3, entry 2). MS (EI) 261 (M+)
9b N-(4-methoxybenzyl)naphthalene-2-amine (Table 3, entry 2b). MS (EI) 263 (M+)
8c 4-((naphthalene-2-ylamino)methyl)phenol (Table 3, entry 3a). MS (EI) 247 (M+)
3. Copies of MS spectra