Catalysis Communications
journal homepage: www.elsevier.com/locate/catcom
Short Communication
Mechanism study on Raney nickel-catalyzed amination of resorcinol
Xin Ge, Jiong-bin Pan, Chao Qian ⁎, Lie Feng, Yun-bin Chen, Xin-zhi Chen
Key Laboratory of Biomass Chemical Engineering of Ministry of Education, Zhejiang University, Hangzhou 310027, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 31 July 2013
Received in revised form 2 December 2013
Accepted 18 December 2013
Available online 24 December 2013
Amination of resorcinol catalyzed by Raney nickel has been examined with good yield. Using the first principle
density functional theory, some detailed mechanism of the amination of resorcinol on the Ni(111) surface is ex-
plored. The resorcinol is adsorbed on the Ni surface at the hollow site to form ketone by isomerization. The isom-
erization has a barrier of 122.1 kJ/mol. Ketone can couple with secondary amine mediated by resorcinol to afford
hemiaminal. For the formation of hemiaminal, the steric effect of the alkyl group of secondary amine is obvious.
Hemiaminal undergoes dehydration to get final product, which occurs by the preferred adsorption in the bridge
site, cleavage of C\O bond initially, followed by subsequent cleavage of C\H bond.
Keywords:
Amination
Raney Ni
Resorcinol
Catalysis
© 2013 Elsevier B.V. All rights reserved.
1
. Introduction
-(N,N-dialkylamino)phenol is the key intermediate that has a wide
2. Experimental section
3
General procedure for the amination of resorcinol with secondary
amine catalyzed by Raney Ni. Resorcinol (2.2 g, 20 mmol), secondary
amine (30 mmol) and Raney Ni (110 mg) were added to water
(50 ml) in a 100 ml autoclave. The autoclave was purged with hydro-
gen gas three times, then maintained 0.05 Mpa pressure. The mixture
was heated to 200 °C rapidly. Then stirring was maintained for 3 h.
The reaction mixture was cooled to room temperature, and then ex-
application in pharmaceuticals and dyes. 3-(N,N-dimethylamino)phe-
nol is used to synthesize neostigmine bromide, which has a reversible
cholinesterase inhibition and is a useful drug in the treatment of myas-
thenia gravis [1]. Astrazon Blue BG (Basic Blue 3) that synthesized by 3-
(N,N-diethylamino)phenol, is one of the dyes most commonly used in
nylon and acrylic textiles [2].
The alkylation of alkyl halides with 3-aminophenol is a classical
procedure [3]. However, it needs a large number of acid-binding
agents and the atom economy of this route is poor. With the rise of
green chemistry, the atom efficiency has become important. In the
synthesis of 3-(N,N-dimethylamino)phenol, there are only two
method with the high atom economy. One of them is the reduction
amination of 3-aminophenol with aldehyde [4], which proceeds
addition of 3-aminophenol with aldehyde, dehydration and reduction
by metal-catalyzed hydrogenation [5] or reducing agent [6]. The other
attractive protocol is the amination of resorcinol with secondary
amines. It is reported that phosphorous acid [7] and metaphosphoric
acid [8] can catalyze this reaction and the byproduct is only water.
The amination of resorcinol is also a relatively green method, but the
catalysts such as phosphorous acid and metaphosphoric acid could pol-
lute environment and its yield has room for improvement.
4
tracted with N-butyl acetate. The organic layer was dried (MgSO ), fil-
tered and concentrated to give the crude product. The pure product
was got through flash column chromatography on silica gel (petroleum
ether/acetylacetic ester (3/1, v/v)).
3. Computational details
DFT calculations were performed with the program package CASTEP
in Materials Studio of Accelrys Inc. [9–11]. Plane wave basis functions
with spin polarization and the Perdew, Burke, Erzenhof gradient
corrected functional (GGA-PBE) were used [12–15]. The transition state
search was performed with the linear and quadratic synchronoustransit
(LST/QST) complete search [16]. Ultrasoftpseudopotential (USP) was
used to perform simulation of core electron. Energy cut-off of 400.0 eV
was used to improve computational performance [17].
In this paper, we explored Raney Ni-catalyzed amination of resorcin-
ol with secondary amines and described a detailed investigation on
mechanism studies on the Ni surface.
Ni(111) surface was modeled using three-layer periodicslab model
with a (6 × 6) super cell including 10 Å vacuum slab, within which
the adsorption and reaction occurs. The reciprocal space of the (6 × 6)
super cell was sampled with the k-points set of (3 × 3 × 2). Larger k-
points sets are needed if more accurate energy value wanted. Study in
this work focused on the relative results of different systems, so the k-
points set of (3 × 3 × 2) should be enough. Geometry optimization
was performed for all the relevant adsorbates with Ni atoms
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