2040
N. A. Ross et al. / Tetrahedron 60 (2004) 2035–2041
1H), 6.83–6.93 (m, 2H), 6.96–7.07 (m, 1H), 7.07–7.16 (m,
2H), 7.19–7.29 (m, 2H), 7.29–7.36 (m, 2H); 13C NMR d
17.9, 22.7, 55.1, 55.3, 66.1, 114.0, 117.2, 123.5, 127.3,
127.7, 128.9, 137.8, 159.3, 171.5. Anal. Calcd for
C18H19NO2: C, 76.84; H, 6.81; N, 4.98. Found: C, 77.14;
H, 6.86; N, 5.06.
in 92% yield after chromatography, flash Kugelrohr
distillation up to 132 8C and recrystallization from hexanes;
light yellow solid; mp 63–64 8C; IR (deposit from CH2Cl2
1
solution onto a NaCl plate) 3429, 1720 cm21; H NMR
(CDCl3) d 1.09–1.21 (m, 6H), 1.25 (s, 3H), 3.84 (s, 3H),
4.02–4.19 (m, 2H), 4.55 (d, J¼7.6 Hz, 1H), 5.36 (d,
J¼7.4 Hz, N–H), 6.25–6.36 (m, 1H), 6.48–6.58 (m, 1H),
6.58–6.67 (m, 1H), 6.67–6.73 (m, 1H), 7.11–7.21 (m, 1H),
7.21–7.34 (m, 4H); 13C NMR d 13.9, 20.5, 24.2, 46.9,
55.5, 60.7, 64.0, 109.2, 110.6, 116.1, 120.9, 127.2, 127.8,
128.3, 136.9, 139.4, 146.7, 176.3. Anal. Calcd for
C20H25NO3: C, 73.37; H, 7.70; N, 4.28. Found: C, 73.58;
H, 7.72; N, 4.35.
4.1.4. 3,3-Dimethyl-1-phenyl-4-(4-trifluoromethyl-
phenyl)-2-azetidinone (27). The title compound was
prepared in 79% yield after chromatography, flash
Kugelrohr distillation up to 130 8C, and recrystallization
from hexanes; white solid; mp 91–94 8C; IR (deposit from
1
CH2Cl2 solution onto a NaCl plate) 1755 cm21; H NMR
(CDCl3) d 0.85 (s, 3H), 1.55 (s, 3H), 4.87 (s, 1H), 7.01–7.14
(m, 1H), 7.20–7.31 (m, 4H), 7.34 (d, J¼7.9 Hz, 2H), 7.62
(d, J¼8.2 Hz, 2H); 13C NMR d 17.9, 22.7, 55.7, 65.8, 117.0,
123.9, 125.64, 125.66, 125.69, 125.73, 126.9, 137.5, 139.8,
170.9. Anal. Calcd for C18H16F3NO: C, 67.70; H, 5.05; N,
4.39. Found: C, 67.93; H, 5.03; N, 4.39.
4.1.9. 1-(2-Ethylphenyl)-3,3-dimethyl-4-phenyl-2-aze-
tidinone (31). The title compound was prepared in 82%
yield after chromatography and recrystallization from
hexanes; white solid; mp 104–105 8C; IR (deposit from
1
CH2Cl2 on a NaCl plate) 1752 cm21; H NMR (CDCl3) d
0.91 (s, 3H), 1.28 (t, J¼7.6 Hz, 3H), 1.53 (s, 3H), 2.73–2.90
(m, 2H), 5.04 (s, 1H), 7.07–7.13 (m, 2H), 7.14–7.19 (m,
2H), 7.19–7.24 (m, 2H), 7.24–7.33 (m, 3H); 13C NMR d
14.0, 18.3, 22.5, 24.9, 54.5, 68.1, 122.5, 126.1, 126.2, 126.5,
127.7, 128.4, 129.3, 134.1, 136.1, 137.2, 171.9. Anal. Calcd
for C19H21NO: C, 81.68; H, 7.58; N, 5.01. Found: C, 81.76;
H, 7.58; N, 5.03.
4.1.5. 4-(4-Dimethylaminophenyl)-3,3-dimethyl-1-
phenyl-2-azetidinone (28). The title compound was
obtained in 72% yield after chromatography and
recrystallization from hexanes; white solid; mp 139–
141 8C (lit. mp 141–142 8C);28 IR (deposit from CH2Cl2
solution onto a NaCl plate) 1740 cm21; 1H NMR (CDCl3) d
0.87 (s, 3H), 1.47 (s, 3H), 2.92 (s, 6H), 4.71 (s, 1H), 6.67 (d,
J¼8.7 Hz, 2H), 6.95–7.03 (m, 1H), 7.05 (d, J¼8.5 Hz, 2H),
7.14–7.28 (m, 2H), 7.28–7.41 (m, 2H); 13C NMR d17.8,
22.6, 40.2, 55.2, 66.3, 112.1, 117.2, 122.4, 123.3, 127.4,
128.8, 137.9, 150.0, 171.8. Anal. Calcd for C19H22N2O:
C, 77.52; H, 7.53; N, 9.52. Found: C, 77.82; H, 7.56; N,
9.60.
4.1.10. 1-tert-Butyl-3,3-dimethyl-4-phenyl-2-azetidinone
(33). The title compound was realized in 93% yield after
chromatography and recrystallization from hexanes; light
yellow solid; mp 81–83 8C (lit. mp 85.5–87 8C);29 IR
(deposit from CH2Cl2 solution onto a NaCl plate)
1732 cm21 1H NMR (CDCl3) d 0.72 (s, 3H), 1.31 (s,
;
9H), 1.35 (s, 3H), 4.34 (s, 1H), 7.20–7.32 (m, 3H), 7.32–
7.41 (m, 2H); 13C NMR d17.3, 22.6, 53.3, 53.7, 66.1, 123.5,
126.8, 127.6, 128.1, 138.6, 174.6. Anal. Calcd for
C15H21NO: C, 77.88; H, 9.15; N, 6.05. Found: C, 77.86;
H, 9.22; N, 6.11.
4.1.6. 1-(4-Methoxyphenyl)-3,3-dimethyl-4-phenyl-2-
azetidinone (30). The title compound was realized in 79%
yield after chromatography and recrystallization from
dichloromethane–hexanes; light purple solid; mp 140–
144 8C; IR (deposit from CH2Cl2 solution onto a NaCl plate)
1748 cm21; 1H NMR1H NMR (CDCl3) d 0.84 (s, 3H), 1.51
(s, 3H), 3.74 (s, 3H), 4.77 (s, 1H), 6.72–6.85 (m, 2H), 7.13–
7.23 (m, 2H), 7.23–7.29 (m, 2H), 7.29–7.39 (m, 3H); 13C
NMR d 17.9, 22.7, 55.31, 55.33, 66.5, 114.2, 118.4, 126.5,
127.9, 128.6, 131.4, 135.6, 155.8, 170.8. Anal. Calcd for
C18H19NO2: C, 76.84; H, 6.81; N, 4.98. Found: C, 77.08; H,
6.71; N, 5.00.
4.1.11. 1-Benzyl-3,3-dimethyl-4-phenyl-2-azetidinone
(34). The title compound was prepared in 92% yield after
chromatography, flash Kugelrohr distillation up to 140 8C
1
and hexanes wash; colorless oil; IR (neat) 1751 cm21; H
NMR (CDCl3) d 0.79 (s, 3H), 1.35 (s, 3H), 4.42 (dd, J¼14.9,
14.9 Hz, 2H), 4.10–4.20 (s, 1H), 7.08–7.19 (m, 4H), 7.22–
7.33 (m, 4H), 7.33–7.41 (m, 2H); 13C NMR d 17.6, 22.2,
44.0, 56.0, 65.7, 126.7, 127.5, 127.8, 128.3, 128.5, 128.6,
135.7, 135.9, 174.0. Anal. Calcd for C18H19NO: C, 81.47;
H, 7.22; N, 5.28. Found: C, 81.20; H, 7.15; N, 5.23.
4.1.7. Ethyl 2,2-Dimethyl-3-phenyl-3-(4-trifluoromethyl-
phenylamino)propionate (19). The title compound was
prepared in 82% yield after chromatography, flash
Kugelrohr distillation up to 135 8C, and recrystallization
from hexanes; yellow solid; mp 52–54 8C; IR (deposit from
4.1.12. Ethyl 3-benzenesulfonylamino-2,2-dimethyl-3-
phenylpropionate (22). The title compound was obtained
in 98% yield after chromatography and recrystallization
from ethyl acetate–hexanes; white solid; mp 128–130 8C;
IR (deposit from CH2Cl2 solution onto a NaCl plate) 3269,
1
CH2Cl2 solution onto a NaCl plate) 3405, 1719 cm21; H
NMR (CDCl3) d1.11–1.20 (m, 6H), 1.30 (s, 3H), 4.06–4.19
(m, 2H), 4.46 (d, J¼7.6 Hz, 1H), 5.32 (d, J¼7.4 Hz, N–H),
6.50 (d, J¼8.7 Hz, 2H), 7.15–7.35 (m, 7H); 13C NMR d
14.0, 20.7, 24.8, 46.6, 61.0, 64.2, 112.4, 126.34, 126.37,
126.40, 126.43, 127.7, 128.1, 128.2, 138.5, 149.4, 176.4.
Anal. Calcd for C20H22F3NO2: C, 65.74; H, 6.07; N, 3.83.
Found: C, 65.53; H, 6.12; N, 3.82.
1728 cm21 1H NMR (CDCl3) d 1.09 (s, 3H), 1.19 (t,
;
J¼7.2 Hz, 3H), 1.28 (s, 3H), 4.08 (q, J¼7.1 Hz, 2H), 4.45
(d, J¼9.9 Hz, 1H), 6.45 (d, J¼9.8 Hz, NH), 6.81–6.96 (m,
2H), 6.96–7.09 (m, 3H), 7.10–7.22 (m, 2H), 7.25–7.36 (m,
1H), 7.44–7.63 (m, 2H); 13C NMR d 13.9, 22.1, 24.3, 46.9,
61.0, 64.6, 126.7, 127.3, 127.7, 127.9, 128.3, 131.7, 136.7,
140.4, 175.9. Anal. Calcd for C19H23NO4S: C, 63.13; H,
6.41; N, 3.88. Found: C, 63.28; H, 6.49; N, 3.94.
4.1.8. Ethyl 3-(2-methoxyphenylamino)-2,2-dimethyl-3-
phenylpropionate (20). The title compound was obtained