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R. K. Singh et al. / Tetrahedron 61 (2005) 8868–8874
7.26–7.31 (m, 5H, ArH); m/z 248 (MC1); [a]2D4 C52.9 (c 1,
MeOH) {lit.,9 [a]D24 C51.3 (c 2.1, EtOAc)}. Anal. Calcd for
C14H17NO3 (247.29): C, 68.00; H, 6.93; N, 5.66. Found: C,
67.81; H, 6.66; N, 5.95%.
4.9. (1R,3S)-5-(2-Oxo-2-phenyl-ethylidene)-1-(1-phenyl-
ethyl)-pyrrolidine-3-carboxylic acid methyl ester (17)
This was obtained in 74% yield as light yellow thick oil by
condensing phenacyl bromide with thiolactam 16 according
to the procedure described for compound 3; nmax (CH2Cl2)
1735, 1625, 1576, 1539 cmK1; dH (300 MHz, CDCl3) 1.65
(d, JZ6.9 Hz, 3H, CHCH3), 3.20–3.25 (m, 2H, 3-CH2),
3.54–3.64 (m, 5H, 5-CH2, CO2CH3), 3.75–3.78 (m, 1H, 4-
CH), 5.05 (q, JZ7.0 Hz, 1H, CHCH3), 5.86 (s, 1H, COCH),
7.29–7.41 (m, 8H, ArH), 7.67–7.79 (m, 2H, ArH); m/z 350
(MC1); [a]2D4 C168.6 (c 0.7, MeOH). Anal. Calcd for
C22H23NO3 (349.42): C, 75.62; H, 6.63; N, 4.01. Found: C,
75.81; H, 6.59; N, 3.95%.
Compound 15 was isolated in 47% yield as long needles, mp
68–69 8C (lit.,9 mp 70 8C); nmax (KBr) 1736, 1682, 1493,
1434 cmK1; dH (300 MHz, CDCl3) 1.56 (d, JZ7.0 Hz, 3H,
CHCH3), 2.69–2.79 (m, 2H, 3-CH2), 3.16–3.25 (m, 2H,
5-CH2), 3.52–3.60 (m, 1H, 4-CH), 3.67 (s, 3H, CO2CH3),
5.52 (q, JZ7.0 Hz, 1H, CHCH3), 7.30–7.40 (m, 5H, ArH);
m/z 248 (MC1); [a]D24 C107.2 (c 1, MeOH) {lit.,9 [a]2D4
C109.6 (c 2.6, EtOAc)}. Anal. Calcd for C14H17NO3
(247.29): C, 68.00; H, 6.93; N, 5.66. Found: C, 68.05; H,
7.13; N, 5.49%.
4.10. (1R,2R)-2-[(1-Phenyl-ethylamino)-methyl]-3-(5-
phenyl-1H-pyrazol-3-yl)-propionic acid methyl ester (9)
4.6. (1R,3R)-1-(1-Phenyl-ethyl)-5-thioxo-pyrrolidine-3-
carboxylic acid methyl ester (7)
This was obtained in 59% yield as oil by condensing
hydrazine dihydrochloride with enaminone 8 according to
the procedure described for compound 4; nmax (CH2Cl2)
3208, 2905, 1732, 1568, 1436 cmK1; dH (300 MHz, CDCl3)
1.35 (d, JZ6.8 Hz, 3H, CHCH3), 2.69–2.79 (m, 2H, NCH2),
2.86–2.94 (m, 2H, CHCH2), 2.99–3.05 (m, 1H, CHCO2-
CH3), 3.68 (s, 3H, CO2CH3), 3.75 (q, JZ6.0 Hz, 1H,
CHCH3), 6.28 (s, 1H, ArH), 7.21–7.41 (m, 8H, ArH), 7.67–
7.70 (m, 2H, ArH); m/z 364 (MC1); [a]2D4 C19.2 (c 0.5,
MeOH). Anal. Calcd for C22H25N3O2 (363.45): C, 72.70; H,
6.93; N, 11.56. Found: C, 72.99; H, 6.90; N, 11.39%.
This was obtained from 6 as thick oil in 90% yield according
to the procedure described for compound 2; nmax (CH2Cl2)
1737, 1495, 1443 cmK1; dH (300 MHz, CDCl3) 1.61 (d, JZ
7.2 Hz, 3H, CHCH3), 3.13 (dd, JZ7.2, 8.7 Hz, 1H, 3-CHa),
3.31–3.43 (m, 3H, 3-CHb and 5-CH2), 3.72 (s, 3H,
CO2CH3), 3.86 (dd, JZ6.3, 6.1 Hz, 1H, 4-CH), 6.34 (q,
JZ7.2 Hz, 1H, CHCH3), 7.31–7.35 (m, 5H, ArH); m/z 264
(MC1); [a]2D4 C70.9 (c 1, MeOH). Anal. Calcd for
C14H17NO2S (263.36): C, 63.85; H, 6.51; N, 5.32. Found:
C, 63.78; H, 6.42; N, 5.28%.
4.11. (1R,2S)-2-[(1-Phenyl-ethylamino)-methyl]-3-(5-
phenyl-1H-pyrazol-3-yl)-propionic acid methyl ester
(18)
4.7. (1R,3S)-1-(1-Phenyl-ethyl)-5-thioxo-pyrrolidine-3-
carboxylic acid methyl ester (16)
This was obtained from 15 as thick oil in 85% yield
according to the procedure described for compound 2; nmax
(CH2Cl2) 1737, 1495, 1451 cmK1; dH (300 MHz, CDCl3)
1.61 (d, JZ7.2 Hz, 3H, CHCH3), 3.20–3.60 (m, 4H, 3-CH2
and 5-CH2), 3.64 (s, 3H, CO2CH3), 3.74–3.81 (m, 1H, 4-
CH), 6.36 (q, JZ7.2 Hz, 1H, CHCH3), 7.30–7.40 (m, 5H,
ArH); m/z 264 (MC1); [a]2D4 C133 (c 1, MeOH). Anal.
Calcd for C14H17NO2S (263.36): C, 63.85; H, 6.51; N, 5.32.
Found: C, 63.90; H, 6.67; N, 5.21%.
This was obtained in 69% yield as thick oil by condensing
hydrazine dihydrochloride with enaminone 17 according to
the procedure described for compound 4; nmax (CH2Cl2)
3344, 2923, 1732, 1493, 1463 cmK1; dH (300 MHz, CDCl3)
1.30 (d, JZ6.8 Hz, 3H, CHCH3), 2.60–2.85 (m, 2H, NCH2),
2.90–3.06 (m, 3H, CHCH2, CHCO2CH3), 3.65 (s, 3H,
CO2CH3), 3.78 (q, JZ7.0 Hz, 1H, CHCH3), 6.30 (s, 1H,
ArH), 7.22–7.41 (m, 8H, ArH), 7.68–7.70 (m, 2H, ArH); m/z
364 (MC1); [a]2D4 C15.9 (c 0.51, MeOH). Anal. Calcd for
C22H25N3O2 (363.45): C, 72.70; H, 6.93; N, 11.56. Found:
C, 72.57; H, 7.03; N, 11.60%.
4.8. (1R,3R)-5-(2-Oxo-2-phenyl-ethylidene)-1-(1-phenyl-
ethyl)-pyrrolidine-3-carboxylic acid methyl ester (8)
4.12. (1R,2R)-3-(1,5-Diphenyl-1H-pyrazol-3-yl)-2-[(1-
phenyl-ethylamino)-methyl]-propionic acid methyl ester
(10)
This was obtained in 71% yield as light yellow solid by
condensing phenacyl bromide with thiolactam 7 according
to the procedure described for compound 3, mp 89–90 8C;
nmax (KBr) 1733, 1625, 1532, 1374 cmK1; dH (300 MHz,
CDCl3) 1.66 (d, JZ6.9 Hz, 3H, CHCH3), 3.13–3.37 (m, 2H,
3-CH2), 3.61–3.69 (m, 2H, 5-CH2), 3.72 (s, 3H, CO2CH3),
3.87 (dd, JZ9.3, 9.6 Hz, 1H, 4-CH), 5.09 (q, JZ6.9 Hz, 1H,
CHCH3), 5.93 (s, 1H, COCH), 7.28–7.44 (m, 8H, ArH),
7.80–7.83 (m, 2H, ArH); dC (75 MHz, CDCl3) 187.0, 174.5,
169.0, 137.2, 136.7, 134.3, 129.7, 129.0, 128.3, 128.1,
126.8, 93.5, 53.7, 53.0, 50.7, 47.5, 35.7, 22.3; m/z 350 (MC
1); [a]2D4 C341.1 (c 0.7, MeOH). Anal. Calcd for
C22H23NO3 (349.42): C, 75.62; H, 6.63; N, 4.01. Found:
C, 75.63; H, 6.77; N, 4.15%.
This was obtained in 59% yield as thick oil by condensing
phenylhydrazine with enaminone 8 according to the
procedure described for compound 4; nmax (CH2Cl2) 1739,
1696, 1610, 1585 cmK1; dH (300 MHz, CDCl3) 1.28 (d, JZ
6.6 Hz, 3H, CHCH3), 2.70–2.74 (m, 2H, NCH2), 2.79–2.88
(m, 1H, CHCO2CH3), 3.01–3.06 (m, 2H, CHCH2), 3.67 (s,
3H, CO2CH3), 3.74 (q, JZ6.8 Hz, 1H, CHCH3), 6.16 (s, 1H,
ArH), 7.11–7.26 (m, 15H, ArH); m/z 440 (MC1); [a]D24
C20.0 (c 0.25, MeOH). Anal. Calcd for C28H29N3O2
(439.55): C, 76.51; H, 6.65; N, 9.56. Found: C, 76.29; H,
6.49; N, 9.77%.