1,1′‑Butylenebis(3‑sulfo‑3H‑imidazol‑1‑ium) hydrogensulfate: a versatile task‑speciꢀc…
using silica gel SIL G/UV 254 plates. The FT-IR spectra
were recorded on a Perkin Elmer 781 Spectrophotometer
160.3, 158.7 (C–NH ), 145.7, 134.6 (C–Cl), 127.4, 122.5,
2
117.3 (C≡N), 104.0, 98.4, 56.3, 39.5 (CH), 19.6 ppm; MS:
−
1
1
+
in the range oꢀ 4000–400 cm . In all the cases, the H
m/z=349.01 ([M+H] ).
1
3
and C NMR spectra were recorded with Bruker Avance
00 MHz instruments. All chemical shiꢀts are quoted in parts
4
2‑Amino‑4‑(2‑methoxyphenyl)‑7‑methyl‑5‑oxo‑4H,5H‑py‑
rano[4,3‑b]pyran‑3‑carbonitrile (2i, C H N O ) Mp.: 242–
per million (ppm) relative to TMS using deuterated solvent.
Microanalyses were perꢀormed on a Perkin-Elmer 240-B
microanalyzer. Melting points were recorded on a Büchi
B-545 apparatus in open capillary tubes. The mass spectra
oꢀ the products were recorded using an Agilent 6560 iFunnel
Q-TOF LC–MS instrument. Ball milling was perꢀormed in
1
7 14 2 4
244 °C; FT-IR (KBr): v̄ = 3385, 3295, 2195, 1710, 1676,
−
1 1
1640, 1605, 1380, 1260 cm ; H NMR (400 MHz, DMSO-
d ): δ= 7.20–7.18 (m, 1H), 7.05–6.98 (m, 2H), 6.92–6.87
6
1
3
(m, 3H), 4.70 (s, 1H), 3.68 (s, 3H), 2.30 (s, 3H) ppm;
C
NMR (100 MHz, DMSO-d ): δ = 164.7, 162.0 (C=O),
6
3
a Retsch PM100 planetary ball mill using a 25 cm stainless
158.8, 158.5 (C–NH ), 155.7, 132.6, 130.6, 128.4, 120.5,
2
steel chamber and two or ꢀour stainless steel balls (diameter:
118.3 (C≡N), 112.0, 102.9, 98.4, 56.3 (O–CH ), 55.7, 35.5
3
+
5
or 7 mm) with 300–600 revolution per minute (rpm).
(CH), 19.7 ppm; MS: m/z=311.10 ([M+H] ).
Typical procedure for the synthesis
of pyran‑annulated derivatives in the presence
of BBSI‑HSO4
2 ‑ A m i n o ‑ 4 ‑ [ 4 ‑ ( t r i f l u o r o m e t h y l ) p h e n y l ] ‑ 7 ‑ m e ‑
thyl‑5‑oxo‑4H,5H‑pyrano[4,3‑b]pyran‑3‑carbonitrile (2l,
C H F N O ) Mp.: 217–219 °C; FT-IR (KBr): v̄ = 3395,
17
11 3 2 3
−
1 1
3
325, 2190, 1685, 1655, 1370, 1325, 1120 cm ; H NMR
The aldehyde (1.0 mmol), malononitrile (1.0 mmol),
(400 MHz, DMSO-d ): δ = 7.70 (d, J = 8.4 Hz, 2H), 7.51
6
hydroxy-6-methyl-2-pyrone (A, 1.0 mmol), and BBSI-HSO
(s, 2H), 7.46 (d, J=8.4 Hz, 2H), 6.27 (s, 1H), 4.58 (s, 1H),
4
1
3
(
5 mol%) were ground at 600 rpm using the planetary ball
2.91 (s, 3H) ppm; C NMR (100 MHz, DMSO-d ): δ =
6
mill at room temperature ꢀor 30 min. The progress oꢀ the
reaction was monitored by TLC. Aꢀter completion oꢀ the
reaction, the product was extracted by hot ethyl acetate,
which aꢀter evaporation oꢀ solvent provided a solid crude
product. The pure product was obtained by recrystalliza-
tion ꢀrom ethanol without tedious column chromatographic
puriꢂcation. The structure oꢀ each puriꢂed pyran annulated
derivatives was conꢂrmed by melting point and spectral
163.8, 162.4 (C=O), 159.0, 157.9 (C–NH ), 143.8, 134.6
2
2
1
(q, J = 28 Hz), 129.9, 125.6 (q, J = 273 Hz), 125.1
C-F
C-F
3
(q, J =4 Hz), 118.3 (C≡N), 105.2, 98.4, 55.8, 39.5 (CH),
C-F
+
19.8 ppm; MS: m/z=349.08 ([M+H] ).
2‑Amino‑4‑(4‑fluorophenyl)‑7‑methyl‑5‑oxo‑4H,5H‑py‑
rano[4,3‑b]‑pyran‑3‑carbonitrile (2m, C H FN O ) M.p.:
1
6
11
2 3
220–222 °C; FT-IR (KBr): v̄ = 3398, 3322, 1688, 1648,
1
13
−1 1
studies including FT-IR, H NMR, C NMR, MS, and ele-
mental analysis. All the known compounds had physical and
spectroscopic data identical to the literature data.
1368, 1329, 1117 cm ; H NMR (400 MHz, DMSO-d ):
6
δ= 7.25–7.12 (m, 6H), 6.28 (s, 1H), 4.31 (s, 1H), 2.22 (s,
13
3H) ppm; C NMR (100 MHz, DMSO-d ): δ= 163.4, 162.0
6
1
(
C=O), 161.7 (d, J = 267 Hz), 158.6, 158.5 (C–NH ),
C-F
2
3
2
‑Amino‑4‑(4‑isopropylphenyl)‑7‑methyl‑5‑oxo‑4H,5H‑py‑
140.2, 129.9 (d, J = 7 Hz), 119.8 (C≡N), 115.6, 115.4
C-F
2
rano[4,3‑b]pyran‑3‑carbonitrile (2d, C H N O ) M.p.: 220–
(d, J =26 Hz), 100.9, 98.5, 58.2, 36.1 (CH), 19.7 ppm;
19
18
2
3
C-F
+
2
1
22 °C; FT-IR (KBr): v̄ = 3365, 3300, 2200, 1715, 1670,
MS: m/z=299.08 ([M+H] ).
−1 1
640, 1615, 1375, 1265 cm ; H NMR (400 MHz, DMSO-
d ): δ = 7.20–7.18 (m, 4H), 7.10 (d, J= 8.8 Hz, 2H), 6.28
6
Acknowledgements The authors are grateꢀul to staꢁ members in the
Analytical and Testing Center oꢀ Nanotechnology & Catalysis Research
Center oꢀ Malaya University.
(
(
s, 1H), 4.25 (s, 1H), 2.89–2.82 (m, 1H), 2.21 (s, 3H), 1.20
1
3
s, 3H), 1.18 (s, 3H) ppm; C NMR (100 MHz, DMSO-
d ): δ = 163.1, 161.7 (C=O), 158.5, 158.4 (C–NH ), 147.3,
6
2
1
41.3, 127.7, 126.7, 119.8 (C≡N), 101.2, 98.2, 58.3, 36.1
(
CH), 33.3 (CH –CH–CH ), 24.2, 24.2, 19.6 ppm; MS:
3
3
+
m/z=323.14 ([M+H] ).
References
2
‑Amino‑4‑(3,5‑dichlorophenyl)‑7‑methyl‑5‑oxo‑4H,5H‑
1
.
Amarasekara AS (2016) Chem Rev 116:6133
2. Sun X, Luo H, Dai S (2012) Chem Rev 112:2100
Koda-Földes R (2014) Molecules 19:8840
pyrano[4,3‑b]pyran‑3‑carbonitrile (2f, C H Cl N O ) Mp.:
1
6
10
2 2 3
3
.
2
1
12–214 °C; FT-IR (KBr): v̄ = 3404, 3330, 2194, 1708,
−
1
1
4. Do JL, Frisčič T (2017) ACS Cent Sci 3:13
676, 1645, 1615, 1382, 1262 cm ; H NMR (400 MHz,
5
.
Martins MAP, Frizzo CP, Moreira DN, Buriol L, Machado P
(2009) Chem Rev 109:4140
DMSO-d ): δ = 7.46 (t, J=1.8 Hz, 1H), 7.20–7.18 (m, 2H),
6
6
.98 (s, 2H), 6.30 (s, 1H), 4.46 (s, 1H), 2.28 (s, 3H) ppm;
1
3
C NMR (100 MHz, DMSO-d ): δ= 164.1, 162.0 (C=O),
6
1
3