Journal of the Iranian Chemical Society
stretching), 1370, 1120 cm−1 (–SO2–NH– stretching),
stretching), 1108 cm−1(C–N–C stretching), 760 (C–Cl
1
1
930 cm−1 (S–N stretching), 635 (C–Br stretching); H
stretching); H NMR (300 MHz, DMSO d6): δ 1.40–1.49
NMR (300 MHz, DMSO d6) δ 7.27–7.38 (m,2H, Ar–H),
7.54–7.62 (m,3H, Ar–H), 7.68–7.75 (m,3H,Ar–H), 12.70 (s,
1H, 1×NH). MS (ESI): m/z=found 353.19 [M++1]; calcd.
351.95.
(m, 2H, piperidine CH2), 1.72–1.78 (m,2H piperidine CH2),
2.00–2.31 (m,2H piperidine CH2), 2.40(s, 3H, 1 × CH3),
2.78–3.00 (m, 1H, piperidine CH), 3.44–3.67 (m, 2H,
piperidine CH2), 7.40–7.42 (m, 2H, Ar–H), 7.61–7.70 (m,
4H, Ar–H); MS (ESI): m/z=found 426.32 [M++1]; calcd.
424.04.
N‑(benzo[d]oxazol‑2‑yl)‑4‑nitrobenzenesulfonamide (13)
Yield (%): 72; white crystalline solid; m.p:189–191 °C;
Rf: 0.44 (ethyl acetate/hexane, 5:5); IR (KBr, cm−1): 3170
(Ar–H stretching), 1650, 1420 cm−1 (benzoxazole and
NO2 stretching), 1370, 1120 cm−1 (–SO2–NH– stretching),
930 cm−1 (S–N stretching); 1H NMR (300 MHz, DMSO d6)
δ 7.27–7.38 (m,2H,Ar–H), 7.59 (ddd, 1H, Ar–H), 7.72 (ddd,
1H, Ar–H), 8.03 (ddd, 2H, Ar–H), 8.10 (ddd, 2H, Ar–H),
12.70 (s, 1H, 1×NH). MS (ESI): m/z=found 320.03 [M+];
calcd. 319.03.
2‑(1‑((4‑Bromophenyl)sulfonyl)
piperidin‑4‑yl)‑5,7‑dichlorobenzo[d]oxazole (17)
Yield (%): 68; white solid; m.p: 209–211 °C; Rf: 0.46 (ethyl
acetate/hexane, 6:4); IR (KBr, cm−1): 3260 cm−1 (Ar–H
stretching), 2900–2800 cm−1 (Piperidine ring stretching),
1650, 1420 cm−1(benzoxazole stretching), 1170 cm−1 (–SO2
stretching), 1108 cm−1(C–N–C stretching), 750 (C–Cl
1
stretching), 620 (C–Br stretching); H NMR (300 MHz,
DMSO d6): δ 1.42–1.49 (m, 2H, piperidine CH2), 1.72–1.76
(m,2H piperidine CH2), 1.98–2.21 (m,2H piperidine CH2),
2.78–3.00 (m, 1H, piperidine CH), 3.34–3.62 (m, 2H, piperi-
dine CH2), 7.35 (d, 1H, Ar–H), 7.56–7.61 (m, 2H, Ar–H),
7.69–7.72 (m, 2H, Ar–H), 7.69(m, 1H, Ar–H); MS (ESI):
m/z=found 491.19 [M++3]; calcd. 487.94.
4‑amino‑N‑(benzo[d]oxazol‑2‑yl)benzene sulfonamide (14)
Yield (%): 55; white crystalline solid; m.p:189–191 °C;
Rf: 0.44 (ethyl acetate/hexane, 5:5); IR (KBr, cm−1):
3170 cm−1 (Ar–H stretching), 1650, 1420 cm−1(benzoxazole
stretching), 1570 (NH2 stretching), 1370, 1120 cm−1
1
(–SO2–NH– stretching), 930 cm−1 (S–N stretching); H
2‑(1‑(phenylsulfonyl)piperidin‑4‑yl)benzo[d]oxazole (18)
NMR (300 MHz, DMSO d6) δ 6.07(2H, br,s Ar-NH2),
7.02 (ddd, 2H,Ar–H), 7.27–7.38 (m,2H,Ar–H), 7.59 (ddd,
1H,Ar–H), 7.72 (ddd,1H,Ar–H), 7.83 (ddd,2H, Ar–H),
12.70 (s, 1H, 1×NH). MS (ESI): m/z=found 290.31 [M+];
calcd. 289.05.
Yield (%): 68; gray solid; m.p: 185–187 °C; Rf: 0.54 (ethyl
acetate/hexane, 6:4); IR (KBr, cm−1): 3260 cm−1 (Ar–H
stretching), 2900–2800 cm−1 (Piperidine ring stretching),
1650, 1420 cm−1(benzoxazole stretching), 1160 cm−1
(–SO2 stretching), 1108 cm−1(C–N–C stretching); 1H NMR
(300 MHz, DMSO d6): δ 1.69–1.99 (m, 2H, piperidine CH2),
2.10–2.30 (m,2H piperidine CH2), 2.53–2.60 (m,2H piperi-
dine CH2), 2.70–2.75 (m, 1H, piperidine CH), 3.57–3.74(m,
2H, piperidine CH2), 7.17–7.46 (m, 1H, Ar–H), 7.52–7.91
(m, 8H, Ar–H); MS (ESI): m/z=found 343.41 [M+]; calcd.
342.10.
5,7‑dichloro‑2‑(1‑(phenylsulfonyl)piperidin‑4‑yl)benzo[d]
oxazole (15)
Yield (%): 63; yellow solid; m.p:191–194 °C; Rf: 0.45
(ethyl acetate/hexane, 6:4): IR (KBr, cm−1): 3170 cm−1
(Ar–H stretching), 2900–2800 cm−1 (piperidine ring stretch-
ing), 1650, 1420 cm−1(benzoxazole stretching), 1182 cm−1
(–SO2 stretching), 1108 cm−1(C–N–C stretching), 750 (C–Cl
2‑(1‑Tosylpiperidin‑4‑yl)benzo[d]oxazole (19)
1
stretching); H NMR (300 MHz, DMSO d6) δ 1.67–2.00
(m, 2H, piperidine CH2), 2.07–2.21 (m,2H piperidine CH2),
2.53–2.60 (m,2H piperidine CH2), 3.00–3.21 (m, 1H, piperi-
dine CH), 3.56–3.79 (m, 2H, piperidine CH2), 7.55–7.64
(m, 5H, Ar–H), 7.85–7.88 (m, 2H, Ar–H); MS (ESI):
m/z=found 412.30 [M++1]; calcd. 410.03.
Yield (%): 69; gray solid; m.p:194–200 °C; Rf: 0.64 (ethyl
acetate/hexane, 6:4); IR (KBr, cm−1): 3250 cm−1 (Ar–H
stretching), 2900–2800 cm−1 (Piperidine ring stretching),
1650, 1420 cm−1(benzoxazole stretching), 1170 cm−1
(–SO2 stretching), 1108 cm−1(C–N–C stretching); 1H NMR
(300 MHz, DMSO d6): δ 1.73–1.94 (m, 2H, piperidine CH2),
2.08–2.26 (m,2H piperidine CH2), 2.48(s, 3H, 1 × CH3)
2.55–2.61 (m,2H piperidine CH2), 2.98–3.18 (m, 1H, piperi-
dine CH), 3.59–3.72 (m, 2H, piperidine CH2), 7.09–7.18 (m,
1H, Ar–H), 7.18–7.27 (m, 1H, Ar–H), 7.39–7.50 (m, 1H,
Ar–H), 7.63–7.71 (m, 2 H, Ar–H) 7.71–7.75 (m, 1 H, Ar–H)
5,7‑Dichloro‑2‑(1‑tosylpiperidin‑4‑yl)benzo[d]oxazole (16)
Yield (%): 67; white solid; m.p:201–204 °C; Rf: 0.44 (ethyl
acetate/hexane, 6:4); IR (KBr, cm−1): 3270 cm−1 (Ar–H
stretching), 2900–2800 cm−1 (piperidine ring stretching),
1650, 1420 cm−1(benzoxazole stretching), 1170 cm−1 (–SO2
1 3