660
Klvaňa et al.:
For C30H21NO3 (443.5) calculated: 81.24% C, 4.77% H, 3.16% N; foun d: 81.22% C, 5.20% H,
3.06% N.
[1-(1-Naphthyl)-3,5-diphenyl-1H-pyrrol-2-yl](phenyl)methanone (8). Th e oxidation of per-
ch lorate 7 (3 g, 5.6 m m ol) was perform ed by th e gen eral procedure but th e crude product
was purified by colum n ch rom atograph y (100 g silica gel, petroleum eth er–dich lorom eth an e
1 : 1) prior th e recrystallisation from eth an ol. Yield 2.35 g (93%) of keton e 8, sligh tly yel-
lowish crystals, m .p. 156–158 °C. For IR, 1H NMR an d 13C NMR spectra, see ref.3. For
C
33H23NO (449.6) calculated: 87.77% C, 5.58% H, 3.10% N; foun d: 87.69% C, 5.49% H,
2.99% N.
Reduction of Keton es 6a–6e an d 8. Gen eral Procedure
A solution of a keton e (1 m m ol) in dry dieth yl eth er (12 m l) was stirred an d cooled to
–30 °C un der argon atm osph ere. Th en LiAlH4 (2 m m ol) in dry dieth yl eth er (8 m l) was
added dropwise at th e tem perature n ot exceedin g –25 °C an d th e stirrin g was con tin ued at
–25 to –30 °C for 1 h . After th e startin g keton e was fully con verted to products (TLC, petroleum
eth er–dich lorom eth an e 1 : 1) th e reaction m ixture was decom posed with aqueous 4% NaOH
(4 m l per 1 g LiAlH4), h eated to th e room tem perature, diluted with ben zen e (15 m l) an d fil-
tered. Evaporation of th e filtrates gave con siderably pure products wh ich were, after HPLC
an d 1H NMR an alyses, separated by ch rom atograph y an d/or crystallisation .
(1,3,5-Triphenyl-1H-pyrrol-2-yl)(phenyl)methanol (9a). Th e reduction of keton e 6a (3 g, 7.5
m m ol) gave a wh ite solid th e in dividuality of wh ich (tR = 6.1 m in ) followed from HPLC
(m eth an ol–water 9 : 1) an alysis. Crystallisation from ben zen e–m eth an ol 1 : 1 afforded wh ite
crystals (2.8 g, 92%) of h ydroxy derivative 9a, m .p. 159–162 °C. IR (KBr): 3 549 (OH).
1H NMR (DMSO-d6): 5.88 d, 1 H, J = 3.8 (CCHO); 6.08 d, 1 H, J = 3.8 (OH); 6.60 s, 1 H (H-4);
6.81–7.65 m , 20 H. 13C NMR (DMSO-d6): 65.71 CH (C-OH); 109.83 CH (C-4); 124.65 C;
125.15 CH; 125.66 CH; 125.93 CH; 126.33 CH; 127.18 CH; 127.65 CH; 128.16 CH; 128.31
CH; 128.67 CH; 132.75 C; 134.03 C; 134.35 C; 136.12 C; 138.64 C; 143.05 C. For C29H23NO
(401.5) calculated: 86.75% C, 5.77% H, 3.49% N; foun d: 86.67% C, 6.16% H, 3.39% N.
Atropodiastereoisomeric [1-(2-methylphenyl)-3,5-diphenyl-1H-pyrrol-2-yl](phenyl)methanol (9b).
Th e reduction of keton e 6b (0.35 g, 0.85 m m ol) gave a wh ite-yellowish solid (m .p. 129–133 °C,
yield 89%) con tain in g two isom ers (tR = 111.6 an d 121.5 m in ) in th e ratio 7 : 3 (HPLC,
m eth an ol–water 7 : 3). For IR an d NMR data, see ref.3. For C30H25NO (415.5) calculated:
86.71% C, 6.06% H, 3.37% N; foun d: 86.36% C, 6.31% H, 3.39% N. A sam ple (200 m g) was
subjected to preparative TLC (15 g of Aldrich h igh -purity silica gel with gypsum bin der
an d fluorescen t in dicator at 254 n m , 20 × 20 cm plates) wh ich after elution (10 tim es)
with petroleum eth er–dich lorom eth an e (5 : 1) gave alm ost pure (>99%) m ajor atropodia-
stereoisom er of 9b (lower RF), wh ite crystals, m .p. 130–134 °C. NMR data are given in ref.3.
Atropodiastereoisomeric [1-(2,3-dimethylphenyl)-3,5-diphenyl-1H-pyrrol-2-yl](phenyl)methanol
(9c). Th e reduction of keton e 6c (0.5 g, 1.17 m m ol) gave a wh ite solid (m .p. 126–132 °C,
yield 94%) as a m ixture of two isom ers (HPLC, m eth an ol–water 4 : 1, two partly overlapped
peaks at 30.9 an d 34.7 m in ) in th e ratio 2 : 1. IR (KBr): 3 542. A part of 1H NMR (DMSO-d6):
0.92 s, 3 H; 1.67 s, 3 H; 1.81 s, 3 H; 2.14 s, 3 H; 6.55 s, 1 H; 6.64 s, 1 H. For C31H27NO
(429.6) calculated: 86.68% C, 6.34% H, 3.26% N; foun d: 86.35% C, 6.72% H, 3.18% N. Th e
preparative TLC perform ed as above afforded alm ost pure (>99%) m ajor atropodia-
stereoisom er of 9c (lower RF), wh ite crystals, m .p. 130–134 °C. 1H NMR (DMSO-d6): 0.92 s, 3 H
(Me); 1.81 s, 3 H (Me); 5.90 m , 2 H (OH an d H-6); 6.58 s, 1 H (H-4); 6.70–7.76 m , 19 H.
Collect. Czech. Chem. Commun. (Vol. 65) (2000)