Supporting Information Bis(methoxypropyl) ether-promoted oxidation of aromatic alcohols into ...

68 Pages·2017·4.59 MB·English

Electronic Supplementary Material (ESI) for Green Chemistry.
This journal is © The Royal Society of Chemistry 2018
Supporting Information
Bis(methoxypropyl) ether-promoted oxidation of aromatic
alcohols into aromatic carboxylic acids and aromatic ketones
with O under metal- and base-free conditions
2
Kai-Jian Liua, Si Jianga, Ling-Hui Lua, Ling-Li Tanga, Shan-Shan Tanga, Hai-Shan Tanga,
Zilong Tangc, Wei-Min He*a,b and Xinhua Xub
aHunan Provincial Engineering Research Center for Ginkgo biloba，Hunan University of
Science and Engineering, Yongzhou 425100, China
bState Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University,
Changsha, 410082, China
cKey Laboratory of Theoretical Organic Chemistry and Functional Molecule of Ministry of
Education, Hunan University of Science and Technology, Xiangtan 411201, China
Total number of pages: 68
Total number of figures: 55 (pages S14 – S68)
Table of Contents
1. General information S2
2. Experimental procedure S3
3. Control experiments S4
4. Characterization data of products S7
5. References S13
6. 1H and 13C NMR spectra of products S14
1. General information
S1
Unless otherwise specified, all reagents and solvents were obtained from commercial
suppliers and used without further purification. All reagents were weighed and handled in
air at room temperature. 1H NMR spectra were recorded at 400 MHz and 13C NMR spectra
were recorded at 100 MHz by using a Bruker Avance 400 spectrometer. Chemical shifts were
calibrated using residual undeuterated solvent as an internal reference (1H NMR: CDCl 7.26
3
ppm, 13C NMR: CDCl 77.0 ppm, 1H NMR: DMSO 2.50 ppm, 13C NMR: 40.0 ppm). The
3
following abbreviations were used to describe peak splitting patterns when appropriate: s =
singlet, d = doublet, t = triplet, q = quartet, m = multiplet, brs = broad singlet.
Chromatographic purifications were carried out on a Biotage Isolera Four instrument. Mass
spectra were performed on a spectrometer operating on ESI-TOF. GC-MS were obtained by
EI on a Shimadzu GC-MS 2010.
(x10,000,000)
1.2TIC
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 16.0 17.0
Figure 1. GC spectrum of bis(methoxypropyl) ether
2. Experimental procedure
S2
(a) General procedure for the synthesis of acid 2 and 4
A mixture of alcohol 1 (0.6 mmol) and bis(methoxypropyl) ether (1.8 mmol) was
added to a 5 mL round flask with an O balloon at room temperature. The reaction
2
typically took 12 hours. The progress of the reaction was monitored by TLC or GC-MS.
Upon completion, the reaction was cooled down to room temperature. The reaction
mixture was purified by silica gel column chromatography to afford the desired 2 and
4.
(b). Oxidation of 1a on 54 g with O
2
A mixture of benzyl alcohol 1a (54 g, 0.5 mol) and bis(methoxypropyl) ether (1.5 mol)
was added to a 1000 mL round-bottomed flask with an O bag at room temperature, then
2
the contents were stirred at 120℃ for 35 hours. Upon completion, the reaction was cooled
down to room temperature and concentrated in vacuum to give the crude products. The
crude product was recrystallized in water to give benzoic acid (2a, 51.8 g, 85% yield).

(c). One-pot synthesis of benzyl benzoate
standardconditions
PhCH OH PhCO Bn
2 thenPhCH OH, DCC,DMAP,N 2
2 2
1a 5a
A mixture of benzyl alcohol 1a (0.6 mmol) and bis(methoxypropyl) ether (1.8 mmol)
was added to a 5 mL round flask with an O balloon at room temperature, then the contents
2
were stirred at 120℃ for 12 hours. The contents were cooled to room temperature, benzyl
alcohol (0.6 mmol) was added under N atmosphere, DCC (0.9 mmol), DMAP (0.3 mmol) was
2
slowly added and stirred for 8 hours at room temperature. The reaction was quenched by
adding water and extracted with EtOAc. The organic layer was washed with water and brine,
dried over MgSO , filtered and evaporated under reduced pressure to afford the crude
4
product which was further purified by silica gel column chromatography with petroleum
ether/ethyl acetate as eluent. The overall yield was 86 %.
S3
(d). One-pot synthesis of benzohydrazide
O
standardconditions
PhCH OH
2
thenCDI,N H H O,r.t.16h
2 4 2 Ph NHNH
2
1a 5b
A mixture of benzyl alcohol 1a (0.6 mmol) and bis(methoxypropyl) ether (1.8 mmol)
was added to a 5 mL round flask with an O balloon at room temperature, then the contents
2
were stirred at 120℃ for 12 hours. The contents were cooled to room temperature, CDI
(127 mg, 0.78 mmol) was added. The mixture was stirred at room temperature with the
dropwise addition of N H ·H O 80 % (113 mg, 1.8 mmol) in bis(methoxypropyl) ether (2 ml)
2 4 2
solution over a period of about 5 min. The mixture was magnetically stirred at room
temperature for 16 hours. The reaction was quenched by adding water and extracted with
EtOAc. The organic layer was washed with water and brine, dried over MgSO , filtered and
4
evaporated under reduced pressure to afford the crude product which was further purified
by silica gel column chromatography with petroleum ether/ethyl acetate as eluent. The
overall yield was 84 %.
(e). One-pot synthesis of 2-phenyl-1H-benzo[d]imidazole
H
N
standardconditions
PhCH OH Ph
2 thenPh P,TCCA,o-Phenylenediamine
3 N
1a 5c
A mixture of benzyl alcohol 1a (0.6 mmol) and bis(methoxypropyl) ether (1.8 mmol)
was added to a 5 mL round flask with an O balloon at room temperature, then the contents
2
were stirred at 120℃ for 12 hours. The contents were cooled to room temperature, then
Ph P (157 mg, 0.6 mmol), and TCCA (41.8 mg, 0.18 mmol) was added, and stirring was
3
continued for 30 min. o-Phenylenediamine (65 mg, 0.6 mmol) was added. The mixture was
magnetically stirred at 120 ◦C for 2 hours. The progress of the reaction was monitored by TLC.
Upon completion of the reaction, the crude product was filtered, washed with CH Cl (5 mL),
2 2
and re-crystallised from ethanol. The overall yield was 76 %.
S4
3. Control experiments
O balloon,TEMPO(0.1equiv.)
(a)PhCH OH 2 PhCO H
2 bis(methoxypropyl)ether,120oC 2
1a 2a,N.D.
O balloon,BHT(0.1equiv.)
(b)PhCH2OH bis(m2ethoxypropyl)ether,120oC PhCO2H
1a 2a,trace
(c) PhCH2OH standardreactions PhCO2H
1a
standardreactions
PhCH2OD PhCO2H(D)
1a-d1 time=6h;k /k =1.03
1a 1a-d1
standardreactions
(d)PhCH2OH +PhCD2OH k /k =4.8 PhCO2H(D)
1a 1a-d2
1a 1a-d
2
16OH 18O balloon 16O 18O
(e) 2 +
bis(methoxypropyl)ether
Ph Me Ph Me Ph Me
120oC
3a 16O-4a 18O-4a
MS:M+=120 MS:M+=122
(1) Radical trapped experiment (a or b)
A mixture of benzyl alcohol 1a (69 µL, 0.6 mmol), bis(methoxypropyl) ether (1.8 mmol)
and 2,2,6,6-tetramethyl-1-piperidyloxy (TEMPO, 16 mg, 0.1 mmol) or butyleret
hydroxytoluen (BHT, 22 mg, 0.1 mmol) was added to a 10 mL round-bottomed flask with an
O balloon at room temperature, then the contents were stirred at 120 ℃ for 12 hours. The
2
reaction was cooled down to room temperature and analyzed by GC-MS showed no product
was formation.
(2) Isotopic labeling experiment (c)
A mixture of benzyl alcohol (35 µL, 0.3 mmol) or PhCH OD (35 µL, 0.3 mmol) and
2
bis(methoxypropyl) ether (0.32 mL, 1.8 mmol) was added to a 10 mL round-bottomed flask
with an O balloon at room temperature, then the contents were stirred at 120 ℃ for 6
2
hours. The reaction was cooled down to room temperature and analyzed by 1H NMR spectra.
(3) Isotopic labeling experiment (d)
A mixture of benzyl alcohol (35 µL, 0.3 mmol), bis(methoxypropyl) ether (0.32 mL, 1.8
mmol) and PhCD OH (35 µL, 0.3 mmol) was added to a 10 mL round-bottomed flask with an
2
O balloon at room temperature, then the contents were stirred at 120 ℃ for 6 hours. The
2
reaction was cooled down to room temperature and analyzed by 1H NMR spectra.
(4) 18O -labeling experiment (e)
2
S5
A mixture of 1-phenylethanol (73 µL, 0.6 mmol) and bis(methoxypropyl) ether (0.32 mL,
1.8 mmol) was added to a 10 mL round-bottom flask with an 18O balloon at room
2
temperature, then the contents were stirred at 120 ℃ for 12 hours. The reaction was cooled
down to room temperature and the 16O-4a and 18O-4a was detected by GC-MS.
%
100.0 77
75.0 107
50.0
51
25.0 122
0.0 20 28 32 4345 6163 73 85 91 103 115 120 128
20.0 25.0 30.0 35.0 40.0 45.0 50.0 55.0 60.0 65.0 70.0 75.0 80.0 85.0 90.0 95.0 100.0 105.0 110.0 115.0 120.0 125.0 130.0
Figure 3. MS spectra of 16O-4a and 18O-4a
(5) EPR experiment
The EPR experiment was monitored under following conditions: DMPO (5,5-dimethyl-
1-pyrroline N-oxide ) (11.2uL) was dissolved in dimethoxy dipropyleneglycol (1mL) to form a
100 mM solution. The mixture was stirred under oxygen atmosphere at different for 2 min at
70℃, after that 40 uL of the mixture was transferred to a flat cell and was measured, a
strong signal with a g = 2.002, A = 1.46 mT, A = 1.37 mT, which was coincident with a
N H
peroxyl radical [1,2] was observed (Figure 4a). DMPO (5,5-dimethyl- 1-pyrroline N-oxide )
(11.2 uL), benzyl alcohol (10.3 uL) were dissolved in dimethoxy dipropyleneglycol (1mL) to
form a 100 mM solution. The mixture was stirred under oxygen atmosphere at different for
2 min at 70℃, after that 40 uL of the mixture was transferred to a flat cell and was
measured, despite the peroxyl radcial mentioned above, a sextet signal with a g = 2.002, A
N
= 1.54 mT, AH= 2.206 mT was observed, which was mentioned to be a carbon centered
radical (Figure 4b).
Figure 4. EPR spectrum of the radical trapping experiment.
Measurement conditions: Power 1 mW, Frequency 9.439 GHz, Center field 336.638 mT,
Sweep width 10mT, Modulation width 0.1 mT, Sweep time 1.0 min, Time constant 0.1s,
Amplitude 400.
S6
4. Characterization data of products
benzoic acid (2a)1: 12 h, White solid (68.0 mg, 93 %); eluent (petroleum ether/ethyl acetate = 2 : 1);
1H NMR (400 MHz, DMSO) δ 12.96 (s, 1 H), 7.95 - 7.93 (m, 2 H), 7.64 - 7.60 (m, 2 H), 7.50 (t, J = 8.0 Hz,
2 H); 13C NMR (100 MHz, DMSO) δ 167.8, 133.4, 131.2, 129.8, 129.1.
4-methylbenzoic acid (2b)1: 12 h, White solid (77.5 mg, 95 %); eluent (petroleum ether/ethyl acetate
= 2 : 1); 1H NMR (400 MHz, DMSO) δ 12.80 (s, 1 H), 7.83 (d, J = 8.0 Hz, 2 H), 7.30 (d, J = 8.0 Hz, 2 H),
2.36 (s, 3 H); 13C NMR (100 MHz, DMSO) δ 167.8, 143.6, 129.9, 129.7, 128.5, 21.7.
4-(tert-butyl)benzoic acid (2c)1: 10 h, White solid (87.3 mg, 89 %); eluent (petroleum ether/ethyl
acetate = 1 : 1); 1H NMR (400 MHz, DMSO) δ 12.79 (s, 1 H), 7.87 (d, J = 8.4 Hz, 2 H), 7.51 (d, J = 8.8 Hz,
2 H), 1.29 (s, 9 H); 13C NMR (100 MHz, DMSO) δ 167.8, 156.3, 129.7, 128.5, 125.9, 35.3, 31.4.
4-hydroxybenzoic acid (2d)2: 16 h, White solid (67.1 mg, 81 %); eluent (petroleum ether/ethyl acetate
= 1 : 1); 1H NMR (400 MHz, DMSO) δ 12.43 (s, 1 H), 10.23 (s, 1 H), 7.79 (d, J = 8.8 Hz, 2 H), 6.82 (d, J =
8.8 Hz, 2 H); 13C NMR (100 MHz, DMSO) δ 167.7, 162.1, 132.1, 121.9, 115.6.
4-methoxybenzoic acid (2e)1: 12 h, White solid (74.8 mg, 82 %); eluent (petroleum ether/ethyl
acetate = 1 : 1); 1H NMR (400 MHz, DMSO) δ 12.64 (s, 1 H), 7.89 (d, J = 8.8 Hz, 2 H), 7.02 (d, J = 8.8 Hz,
2 H), 3.82 (s, 3 H); 13C NMR (100 MHz, DMSO) δ 167.5, 163.3, 131.8, 123.5, 114.3, 55.9.
4-(trifluoromethoxy)benzoic acid (2f)1: 9 h, Slight yellow solid (118.5 mg, 96 %, eluent: petroleum
ether/ethyl acetate = 1 : 1; 102.4 mg, 83%, recrystallization from DMF and petroleum ether); 1H NMR
(400 MHz, DMSO) δ 13.23 (s, 1 H), 8.06 (d, J = 8.8 Hz, 2 H), 7.47 (d, J = 8.4 Hz, 2 H); 13C NMR (100 MHz,
DMSO) δ 166.7, 152.0, 132.2, 130.4, 121.2, 120.5 (q, J = 255.9 Hz); 19F NMR (376 MHz, DMSO) δ -56.7.
4-((tert-butyldimethylsilyl)oxy)benzoic acid (2g)3: 10 h, White solid (137.5 mg, 91%, eluent:
petroleum ether/ethyl acetate = 1 : 1; 126.1 mg, 83%, recrystallization from DMF and petroleum
ether); 1H NMR (400 MHz, DMSO) δ 12.65 (s, 1 H), 7.85 (d, J = 8.4 Hz, 2 H), 6.93 (d, J = 8.8 Hz, 2 H),
0.95 (s, 9 H), 0.22 (s, 6 H); 13C NMR (100 MHz, DMSO) δ 167.4, 159.7, 131.9, 124.4, 120.2, 26.0, 18.5, -
4.1.
4-mercaptobenzoic acid (2h)4: 16 h, Gray white solid (77.5 mg, 84 %); eluent (petroleum ether/ethyl
acetate = 1 : 1); 1H NMR (400 MHz, DMSO) δ 13.08 (s, 1 H), 7.93 (d, J = 8.4 Hz, 2 H), 7.64 (d, J = 8.4 Hz,
2 H); 13C NMR (100 MHz, DMSO) δ 167.1, 141.3, 130.8, 130.2, 126.6.
S7
4-(methylthio)benzoic acid (2i)5: 11 h, Gray white solid (87.6 mg, 87 %); eluent (petroleum
ether/ethyl acetate = 1 : 1); 1H NMR (400 MHz, DMSO) δ 12.83 (s, 1 H), 7.85 (d, J = 8.4 Hz, 2 H), 7.33
(d, J = 8.4 Hz, 2 H), 2.52 (s, 3 H); 13C NMR (100 MHz, DMSO) δ 167.6, 145.3, 130.2, 127.3, 125.4, 14.5.
4-(trifluoromethyl)benzoic acid (2j)6: 13 h; White solid (103.7 mg, 91 %, eluent: petroleum
ether/ethyl acetate = 1 : 1; 95.7 mg, 84%, recrystallization from DMF and petroleum ether); 1H NMR
(400 MHz, DMSO) δ 13.52 (s, 1 H), 8.13 (d, J = 8.4 Hz, 2 H), 7.88 (d, J = 8.4 Hz, 2 H); 13C NMR (100 MHz,
DMSO) δ 166.7, 135.1, 132.0 (q, J = 31.7 Hz), 130.7, 126.1, 124.4 (q, J = 271.0 Hz); 19F NMR (376 MHz,
DMSO) δ -61.6.
4-fluorobenzoic acid (2k)7: 10 h, Gray white solid (79.6 mg, 95 %); eluent (petroleum ether/ethyl
acetate = 1 : 1); 1H NMR (400 MHz, DMSO) δ 13.07 (s, 1 H), 8.03 - 7.98 (m, 2 H), 7.35 - 7.29 (m, 2 H);
13C NMR (100 MHz, DMSO) δ 166.9, 165.4 (d, J = 249.1 Hz), 132.7 (d, J = 9.4 Hz), 127.9, 116.1 (d, J =
21.9 Hz); 19F NMR (376 MHz, DMSO) δ -106.9.
4-chlorobenzoic acid (2l)1: 10 h, White solid (88.6 mg, 95 %); eluent (petroleum ether/ethyl acetate =
1 : 1); 1H NMR (400 MHz, DMSO) δ 13.20 (s, 1 H), 7.94 (d, J = 8.8 Hz, 2 H), 7.57 (d, J = 8.4 Hz, 2 H); 13C
NMR (100 MHz, DMSO) δ 167.0, 138.3, 131.7, 130.1, 129.3.
4-bromobenzoic acid (2m)1: 10 h, White solid (111.6 mg, 93 %, eluent: petroleum ether/ethyl acetate
= 2 : 1; 96.1 mg, 80%, recrystallization from DMF and petroleum ether); 1H NMR (400 MHz, DMSO) δ
13.21 (s, 1 H), 7.86 (d, J = 8.4 Hz, 2 H), 7.71 (d, J = 8.4 Hz, 2 H); 13C NMR (100 MHz, DMSO) δ 167.1,
132.2, 131.8, 130.5, 127.4.
4-iodobenzoic acid (2n)1: 10 h, White solid (136.6 mg, 92 %, eluent: petroleum ether/ethyl acetate = 2
: 1; 126.3 mg, 85%, recrystallization from DMF and petroleum ether); 1H NMR (400 MHz, DMSO) δ
13.12 (s, 1 H), 7.89 (d, J = 8.4 Hz, 2 H), 7.69 (d, J = 8.4 Hz, 2 H); 13C NMR (100 MHz, DMSO) δ 167.4,
138.1, 131.6, 130.8, 101.7.
4-nitrobenzoic acid (2o)8: 16 h, Slight yellow solid (67.9 mg, 68 %); eluent (petroleum ether/ethyl
acetate = 2 : 1); 1H NMR (400 MHz, DMSO) δ 13.71 (s, 1 H), 8.32 (d, J = 8.8 Hz, 2 H), 8.17 (d, J = 8.8 Hz,
2 H); 13C NMR (100 MHz, DMSO) δ 166.3, 150.6, 136.9, 131.2, 124.3.
4-cyanobenzoic acid (2p)1: 16 h, Gray white solid (71.6 mg, 81 %); eluent (petroleum ether/ethyl
acetate = 1 : 1); 1H NMR (400 MHz, DMSO) δ 13.60 (s, 1 H), 8.06 (s, 2 H), 8.01 (s, 2 H); 13C NMR (100
MHz, DMSO) δ 133.6, 118.7, 115.5.
4-(methoxycarbonyl)benzoic acid (2q)9: 16 h, White solid (91.9 mg, 85 %); eluent (petroleum
ether/ethyl acetate = 1 : 1); 1H NMR (400 MHz, DMSO) δ 13.37 (s, 1 H), 8.06 (s, 4 H), 3.88 (s, 3 H); 13C
NMR (100 MHz, DMSO) δ 167.1, 166.1, 135.3, 133.7, 130.1, 129.9, 53.0.
S8
4-vinylbenzoic acid (2r): 14 h, White solid (73.5 mg, 83 %); eluent (petroleum ether/ethyl acetate = 1 :
1); 1H NMR (400 MHz, DMSO) δ 12.90 (s, 1 H), 7.91 (d, J = 8.0 Hz, 2 H), 7.59 (d, J = 8.0 Hz, 2 H), 6.81
(dd, J = 17.6, 11.2 Hz, 1 H), 5.98 (d, J = 17.6 Hz, 1 H), 5.41 (d, J = 11.2 Hz, 1 H); 13C NMR (100 MHz,
DMSO) δ 167.6, 141.8, 136.4, 130.4, 130.2, 126.7, 117.5.
3-methylbenzoic acid (2r2s)2: 16 h, Slight yellow solid (66.2 mg, 81 %); eluent (petroleum ether/ethyl
acetate = 1 : 1); 1H NMR (400 MHz, DMSO) δ 12.88 (s, 1 H), 7.76 (s, 1 H), 7.74 (d, J = 7.6 Hz, 1 H), 7.44 -
7.36 (m, 2 H), 2.36 (s, 3 H); 13C NMR (100 MHz, DMSO) δ 167.9, 138.4, 134.0, 131.2, 130.2, 129.0,
127.0, 21.3.
2-methylbenzoic acid (2s2t)3: 16 h, White solid (63.4 mg, 78 %); eluent (petroleum ether/ethyl
acetate = 1 : 1); 1H NMR (400 MHz, DMSO) δ 12.82 (s, 1 H), 7.81 (d, J = 7.6 Hz, 1 H), 7.46 - 7.41 (m, 1
H), 7.28 (t, J = 8.4 Hz, 2 H), 2.51 (s, 3 H); 13C NMR (100 MHz, DMSO) δ 169.2, 139.5, 132.2, 132.0,
130.9, 130.7, 126.4, 21.8.
3,4-dichlorobenzoic acid (2t2u)3: 16 h, White solid (94.7 mg, 83 %); eluent (petroleum ether/ethyl
acetate = 1 : 1); 1H NMR (400 MHz, DMSO) δ 13.51 (s, 1 H), 8.06 (d, J = 2.0 Hz, 1 H), 7.88 (dd, J = 8.4,
1.8 Hz, 1 H), 7.77 (d, J = 8.4 Hz, 1 H); 13C NMR (100 MHz, DMSO) δ 165.9, 136.3, 132.0, 131.9, 131.6,
131.5, 129.8.
terephthalic acid (2u2v)3: 12 h, White solid (90.7 mg, 91 %, eluent: petroleum ether/ethyl acetate = 2
: 1, 81.7 mg, 82%, recrystallization from DMF and petroleum ether); 1H NMR (400 MHz, DMSO) δ
13.31 (s, 2 H), 8.04 (s, 4 H); 13C NMR (100 MHz, DMSO) δ 167.2, 135.0, 130.0.
2-naphthoic acid (2v2w)10: 16 h, White solid (78.4 mg, 76 %); eluent (petroleum ether/ethyl acetate =
2 : 1); 1H NMR (400 MHz, DMSO) δ 13.08 (s, 1 H), 8.61 (s, 1 H), 8.12 (d, J = 5.6 Hz, 1 H), 8.03 - 7.96 (m,
3 H), 7.68 - 7.59 (m, 2 H); 13C NMR (100 MHz, DMSO) δ 168.0, 135.4, 132.7, 131.0, 129.8, 128.9, 128.7,
128.6, 128.2, 127.3, 125.7.
isonicotinic acid (2w2x)10: 12 h, White solid (67.7 mg, 92 %); eluent (petroleum ether/ethyl acetate =
1 : 1); 1H NMR (400 MHz, DMSO) δ 13.71 (s, 1 H), 8.78 (d, J = 6.0 Hz, 2 H), 7.81 (d, J = 6.0 Hz, 2 H); 13C
NMR (100 MHz, DMSO) δ 166.7, 151.1, 138.6, 123.3.
quinoline-6-carboxylic acid (2x2y)11: 16 h, Gray white solid (88.1 mg, 85 %); eluent (petroleum
ether/ethyl acetate = 1 : 1); 1H NMR (400 MHz, DMSO) δ 13.31 (s, 1 H), 9.01 (q, J = 1.6 Hz, 1 H), 8.68 (d,
J = 2.0 Hz, 1 H), 8.57 (d, J = 8.4 Hz, 1 H), 8.22 (dd, J = 8.8, 2.0 Hz, 1 H), 8.09 (d, J = 8.8 Hz, 1 H), 7.63 (q, J
= 4.4 Hz, 1 H); 13C NMR (100 MHz, DMSO) δ 167.6, 153.3, 149.9, 138.1, 131.5, 129.9, 129.3, 129.1,
127.7, 122.8.
furan-2-carboxylic acid (2y2z)1: 12 h, Gray white solid (59.2 mg, 88 %); eluent (petroleum ether/ethyl
S9
acetate = 2 : 1); 1H NMR (400 MHz, DMSO) δ 13.07 (s, 1 H), 7.91 (s, 1 H), 7.21 (d, J = 3.2 Hz, 1 H), 6.65 -
6.64 (m, 1 H); 13C NMR (100 MHz, DMSO) δ 159.8, 147.6, 145.4, 118.2, 112.6.
2,3-dihydrobenzo[b][1,4]dioxine-6-carboxylic acid (2z2aa)12: 16 h, Gray white solid (88.7 mg, 82 %);
eluent (petroleum ether/ethyl acetate = 2 : 1); 1H NMR (400 MHz, DMSO) δ 13.37 (s, 1 H), 6.94 - 6.91
(m, 1 H), 6.88 - 6.79 (m, 3 H), 5.03 (t, J = 3.2 Hz, 1 H), 4.41 (dd, J = 11.6, 3.6 Hz, 1 H), 4.26 (dd, J = 11.6,
2.8 Hz, 1 H); 13C NMR (100 MHz, DMSO) δ 170.1, 143.5, 143.0, 122.3, 121.7, 117.5, 71.8, 65.2.
thiophene-2-carboxylic acid (2aa2ab)1: 16 h, Gray white solid (65.4 mg, 85 %); eluent (petroleum
ether/ethyl acetate = 2 : 1); 1H NMR (400 MHz, DMSO) δ 13.06 (s, 1 H), 7.88 (dd, J = 5.2, 1.2 Hz, 1 H),
7.73 (dd, J = 3.6, 1.2 Hz, 1 H), 7.18 (dd, J = 5.0, 4.0 Hz, 1 H); 13C NMR (100 MHz, DMSO) δ 163.4, 135.2,
133.8, 133.7, 128.8.
Ferroncene Monocarboxylic Acid (2ab2ac)1: 16 h, Yellow solid (107.4 mg, 78 %); eluent (petroleum
ether/ethyl acetate = 2 : 1); 1H NMR (400 MHz, DMSO) δ 12.15 (s, 1 H), 4.70 (t, J = 2.0 Hz, 2 H), 4.44 (t,
J = 2.0 Hz, 2 H), 4.21 (s, 5 H); 13C NMR (100 MHz, DMSO) δ 172.7, 72.4, 71.6, 70.4, 70.0.
isobenzofuran-1(3H)-one (2ac2ad)1: 12 h, White solid (65.8 mg, 82 %); eluent (petroleum ether/ethyl
acetate = 2 : 1); 1H NMR (400 MHz, DMSO) δ 7.85 (d, J = 7.6 Hz, 1 H), 7.80 - 7.76 (m, 1 H), 7.69 - 7.67
(m, 1 H), 7.61 - 7.57 (m, 1 H), 5.42 (s, 2 H); 13C NMR (100 MHz, DMSO) δ 171.2, 147.9, 134.7, 129.5,
125.4, 123.5, 70.4.
4-hydroxy-3,5-dimethoxybenzoic acid (2ad2ae)13: 12 h, Gray white solid (110.4 mg, 93 %, eluent:
petroleum ether/ethyl acetate = 2 : 1, 97.4 mg, 82%, recrystallization from DMF and petroleum
ether); 1H NMR (400 MHz, DMSO) δ 12.61 (s, 1 H), 9.23 (s, 1 H), 7.20 (s, 2 H), 3.80 (s, 6 H); 13C NMR
(100 MHz, DMSO) δ 167.8, 147.9, 140.7, 120.8, 107.3, 56.4.
4,5-dihydroxy-9,10-dioxo-9,10-dihydroanthracene-2-carboxylic acid (2ae2af): 14 h, Yellow brown
solid (158.4 mg, 93 %, eluent: acetone/Benzene = 1 : 6, 146.4 mg, 86%, recrystallization from DMF
and petroleum ether); 1H NMR (400 MHz, DMSO) δ 13.81 (s, 1 H), 11.91 (s, 2 H), 8.12 (s, 1 H), 7.83 (t, J
= 8.0 Hz, 1 H), 7.76 - 7.72 (m, 2 H), 7.41 (d, J = 8.0 Hz, 1 H); 13C NMR (100 MHz, DMSO) δ 191.9, 181.6,
166.0, 161.9, 161.6, 161.6, 138.1, 134.2, 133.8, 125.1, 124.6, 119.9, 119.4, 119.0, 116.7.
acetophenone (4a)14: 8 h, Colorless liquid (67.5 mg, 94 %); eluent (petroleum ether/ethyl acetate = 8 :
1); 1H NMR (400 MHz, CDCl ) δ 7.98 - 7.95 (m, 2 H), 7.59 - 7.54 (m, 1 H), 7.48 - 7.45 (m, 2 H), 2.61 (s, 3
3
H); 13C NMR (100 MHz, CDCl ) δ 198.0, 136.8, 132.9, 128.4, 128.1, 26.4.
3
1-(p-tolyl)ethanone (4b)15: 8 h, Colorless liquid (75.9 mg, 93 %); eluent (petroleum ether/ethyl
acetate = 6 : 1); 1H NMR (400 MHz, CDCl ) δ 7.86 (d, J = 8.0 Hz, 2 H), 7.25 (d, J = 8.0 Hz, 2 H), 2.58 (s, 3
3
H), 2.41 (s, 3 H); 13C NMR (100 MHz, CDCl ) δ 197.7, 143.7, 134.5, 129.1, 128.3, 26.4, 21.5.
3
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