4
766
V. Mehra et al. / Tetrahedron Letters 54 (2013) 4763–4766
2
31. General procedure for the synthesis of trans-3-azido-1-aryl-2-styryl-azetidine 7:
To a stirred solution of 6 (1 mmol) in isopropanol (10 mL) was added sodium
borohydride (2 mmol) at room temperature and the solution was allowed to
stir for 10 h. The progress of reaction was monitored by TLC and on
completion, the reaction mixture was treated with brine and extracted with
chloroform (2 ꢀ 50 mL). The combined organic layers were dried over
anhydrous sodium sulfate and concentrated under reduced pressure. The
crude product was purified via column chromatography on silica gel using a
mixture (10:90) of ethyl acetate and hexane as eluent to obtain azetidine 7.
2
2
trans-3-Azido-2-styryl-1-(p-tolyl)azetidine (7a): Yellow liquid,
d
H
(CDCl
3
,
3
300 MHz), 2.21 (s, 3H, –CH
CH ), 4.25 (dd, J = 5.3, 6.6 Hz, 1H, H ), 6.15 (dd, J = 6.6, 15.6 Hz, 1H, H ), 6.57–
6.65 (m, 3H, 1H, H , 2ArH), 6.97 (d, J = 8.4 Hz, 2H, ArH), 7.20–7.34 (m, 5H,
ArH), d (CDCl , 75 MHz), 20.2, 56.8, 63.2, 67.1, 114.5, 126.5, 127.2, 127.4,
127.8, 128.4, 129.8, 132.5, 136.3, 144.1, m/z 290 (M ).
2098. Anal. Calcd for C18 (290.15): C, 74.46; H, 6.25; N, 19.30%; Found:
C, 74.32; H, 6.38, N, 19.18%.
3
), 3.77–3.81 (m, 1H, H ), 3.86–3.92 (m, 2H, –
2
4
2
5
2
C
3
+
ꢁ1
mmax (KBr)/cm 2852,
18 4
H N
32. General procedure for the synthesis of trans-1-aryl-2-styrylazetidin-3-amines 9
(Path-A): To a stirred solution of 8 (1 mmol) in a isopropanol (10 mL) was
added sodium borohydride (2 mmol) at room temperature and the solution
was allowed to stir for 9 h. The progress of reaction was monitored by TLC and
on completion, the reaction mixture was treated with brine and extracted with
chloroform (2 ꢀ 50 mL). The combined organic layers were dried over
anhydrous sodium sulfate and concentrated under reduced pressure to yield
azetidine 9.
2
2
9. General procedure for the synthesis of trans-(3-buta-1,3-dienyl)/vinyl/isopropenyl-
1,2-diarylazetidines 2: To a stirred solution of 1 (1 mmol) in isopropanol
(
10 mL) was added sodium borohydride (2 mmol) at room temperature and
the solution was allowed to stir for 10 h. The progress of reaction was
monitored by TLC and on completion, the reaction mixture was treated with
brine and extracted with chloroform (2 ꢀ 50 mL). The combined organic layers
were dried over anhydrous sodium sulfate and concentrated under reduced
pressure. The crude product was purified via column chromatography on silica
gel using a mixture (10:90) of ethyl acetate and hexane as eluent. trans-(3-
33. General procedure for the synthesis of trans-1-aryl-2-styrylazetidin-3-amines 9
(Path-B): To a well stirred solution of 7 (1 mmol) in ethanol/water (90:10)
4
was added NH Cl (1.5 mmol) followed by the slow addition of zinc
(1.5 mmol). The reaction mixture was allowed to reflux for 2 h and the
progress of reaction was monitored by TLC. On completion, the reaction
mixture was treated with brine and extracted with ethyl acetate (2 ꢀ 50 ml).
The combined organic layers were dried over anhydrous sodium sulfate and
concentrated under reduced pressure to yield trans-3-amino-1-aryl-2-styryl-
Buta-1,3-dienyl)-1,2-diphenylazetidine (2a): Yellow liquid,
d
H
(CDCl
3
,
3
3
00 MHz), 2.68–2.78 (m, 1H, H ), 3.63 (ddd, J = 5.5, 11.0 and 16.1 Hz, 2H, –
2
7a
2
CH ), 4.61 (d, J = 5.0 Hz, 1H, H ), 5.10 (d, J = 9.8 Hz, 1H, H ), 5.20 (d, J = 16.0 Hz,
7b 4 5 6
1
H, H ), 5.50–5.65 (m, 1H, H ), 6.20–6.35 (m, 2H, H , H ), 6.40–6.52 (m, 3H,
ArH), 7.00–7.31 (m, 7H, ArH), d (CDCl , 75 MHz), 41.2, 58.6, 68.2, 117.1, 118.5,
24.0, 125.5, 125.8, 128.6, 129.1, 129.5, 135.5, 135.9, 137.6, 141.8, m/z 261
azetidines 9. 2-Styryl-1-(p-tolyl)-azetidin-3-amine (9a): Yellow liquid, d
H
3
C
3
(CDCl
2H, –CH
6.54–6.63 (m, 3H, 1H, H , 2H, ArH), 6.95 (d, J = 8.8 Hz, 2H, ArH), 7.22–7.34
(m, 5H, ArH), d (CDCl , 75 MHz), 20.1, 48.6, 63.5, 69.4, 114.3, 126.7, 127.2,
127.3, 127.8, 128.6, 129.9, 132.8, 136.3, 144.6, m/z 264 (M ).
2858. Anal. Calcd for C18 (264.16): C, 81.78; H, 7.63; N, 10.60%; Found:
C, 81.66; H, 7.54, N, 10.72%.
3
, 300 MHz), 2.24 (s, 3H, –CH
3
), 3.74–3.79 (m, 1H, H ), 3.84–3.90 (m,
2
4
1
2
), 4.30 (dd, J = 5.4, 6.8 Hz, 1H, H ), 6.17 (dd, J = 6.8, 15.4 Hz, 1H, H ),
+
ꢁ1
5
(
M ).
mmax (KBr)/cm 2850. Anal. Calcd for C19H19N (261.15): C, 87.31; H, 7.33;
C
3
+
ꢁ1
3
mmax (KBr)/cm
18 4
H N