8642
R. Bianchini et al. / Tetrahedron 68 (2012) 8636e8644
disk) 3411 (br), 2985, 2934, 1703, 1594, 1551, 1479, 1454, 1380, 1371,
1303, 1215, 1145e1070 (br) cmꢀ1
dH (200 MHz, DMSO-d6): 9.04
to the formation of a fine suspension, which was maintained at 0 ꢁC
for a further hour. Then, the whole was filtered under suction. The
solid was washed with H2O (3ꢂ10 mL) and dried in an oven at 70 ꢁC
to obtain the title compound (0.66 g, 88%) as dark orange solid, mp
;
(1H, t, J 5.6 Hz, CONH), 8.05e8.02 (2H, m, AreH), 7.50e7.46 (6H, m,
AreH), 7.29e7.25 (2H, m, Ar-H), 5.32 (1H, d, J 5.2 Hz, CHOH),
4.40e4.29 (2H, m), 4.18e4.00 (7H, m), 3.91e3.81 (2H, m),
3.60e3.53 (2H, m), 3.27e3.21 (2H, m), 3.12 [6H, s, (OCH3)2], 1.43
(3H, s, CH3 acetonide), 1.29 (3H, s, CH3 acetonide), 1.24 (3H, s, CH3
acetonide), 1.21 (3H, s, CH3 acetonide),1.16 (3H, s, CH3 acetonide),1.12
(3H, s, CH3 acetonide); 13C NMR dC (50.3 MHz, DMSO-d6): 162.0,
161.3, 141.8, 138.4, 136.8, 130.5 (2C), 129.4 (2C), 126.7, 126.1, 125.2,
119.3 (2C), 116.7 (2C), 109.5, 109.2, 108.4, 105.5, 103.8, 79.8, 78.0,
76.8, 76.1, 75.8, 74.4, 73.0, 70.4, 66.2, 56.2, 54.7, 41.1, 28.6, 27.5, 27.0
(2C), 26.7, 25.8 ppm; ESI (m/z, þc): 820.4 [MþNa]þ.
273e275 ꢁC, lit.26 277 ꢁC; Rf (10% MeOH/CH2Cl2) 0.40; lmax
( )
3
(MeOH) 274 (20,274), 391 nm (23,647 Mꢀ1 cmꢀ1); nmax (KBr disk)
3400e2400 (br), 1690 (br), 1600 (br), 1550e1480 (br), 1430 (br),
1370, 1340e1200 (br) cmꢀ1
; dH (200 MHz, DMSO-d6) 8.07e7.96
(4H, m, AreH), 7.62e7.58 (2H, m, AreH), 7.47e7.39 (2H, m, AreH),
7.24e7.17 (1H, m, AreH), 2.46 (3H, s, CH3); dC (50.3 MHz, DMSO-d6):
166.8, 156.9, 149.3, 141.3 (2C), 130.4 (2C), 129.5 (2C), 127.3, 126.4,
125.8, 116.9 (2C), 116.3 (2C), 11.6; ESI (m/z, ꢀc): 321.6 [Mꢀ1]ꢀ.
5.1.12. Synthesis of 4-[(4Z)-4-(2-phenylhydrazono)-4,5-dihydro-3-
methyl-5-oxopyrazol-1-yl]-N-{(3aS,4R,6S,7R,7aR)-6-{(R)-[(4S,5R)-5-
(dimethoxymethyl)-2,2-dimethyl-1,3-dioxolan-4-yl]-[(R)-2,2-
dimethyl-1,3-dioxolan-4-yl]methoxy}-tetrahydro-7-hydroxy-2,2-
dimethyl-3aH-[1,3]dioxolo[4,5-c]pyran-4-yl}methylbenzamide
21. The synthesis of compound 21 was carried out on a 1.0 mmol
scale of building block 20 (0.32 g) using 60-aminolactosetriacetonide
9 (610 mg, 1.2 mmol, 1.2 equiv) THF (10 mL) and DMTMM (290 mg,
1.05 mmol, 1.05 equiv) following the experimental, work-up and
purification procedures reported for compound 15, to isolate
a foamy orange solid (0.51 g, 61%), mp 132e133 ꢁC; [Found: C, 59.16;
5.1.9. Synthesis
of
(4Z)-4-(2-phenylhydrazono)-N-
{{(2R,3R,4S,5R,6S)-6-[(2R,3S,4R,5R)-tetrahydro-4,5,6-trihydroxy-2-
(hydroxymethyl)-2H-pyran-3-yloxy]}-tetrahydro-3,4,5-trihydroxy-
2H-pyran-2-yl}methyl-4,5-dihydro-5-oxo-1-phenyl-1H-pyrazole-3-
carboxamide 16. In a 5 mL round bottomed flask glyconjugated
derivative 15 (100 mg, 0.12 mmol) was dissolved in 90% aq TFA13a
(1.5 mL). The dark yellow solution was stirred at 20 ꢁC for 2 h and
then it was diluted with toluene (50 mL) under vigorous stirring for
3 h. The resulting suspension was filtered and the solid was washed
with toluene (3ꢂ10 mL) and dried in vacuo to recover the title
compound (60 mg, 75%) as an indefinite mixture of
a
- and
b-pyr-
H, 6.90; N, 8.66. C40H53N5O13 requires C, 59.18; H, 6.58; N, 8.63]; Rf
20
anosic anomers in the form of orange powder, mp 183e185 ꢁC; Rf
(40% EtOAc/CH2Cl2) 0.37; [
a
]
¼þ13.80 (c 1.32, CHCl3); lmax
( 3 )
D
(MeOH) 258 (17,453), 273 (20,827), 390 nm (24,236 Mꢀ1 cmꢀ1); nmax
(KBr disk) 3436 (br), 2986, 2935, 1662, 1552, 1503, 1370, 1342, 1268,
1219, 1152, 1071 (br); dH (200 MHz, CDCl3) 8.30 (1H, t, J 4.8 Hz,
CONH), 8.05e7.95 (4H, m, AreH), 7.63 (2H, d, J 8.0 Hz, AreH),
7.49e7.44 (2H, m, AreH), 7.27e7.22 (1H, m, AreH), 5.30 (1H, d, J
5.2 Hz, OH), 4.51e4.39 (2H, m), 4.30 (1H, d, J 6.0 Hz), 4.22e3.89 (7H,
m), 3.71e3.69 (1H, m), 3.52e3.48 (2H, m), 3.30e3.25 (2H, m), 3.25
[6H, s, (OCH3)2], 2.3 (3H, s, N¼C-CH3), 1.40 (3H, s, CH3 acetonide),
1.33 [6H, s, (CH3 acetonide)2], 1.30 [6H, s, (CH3 acetonide)2], 1.2 (3H,
s, CH3 acetonide); dC (50.3 MHz, CDCl3), 166.0, 156.8, 149.3, 141.3,
140.1, 130.2, 129.6 (2C), 128.4 (2C), 127.5, 125.8, 116.6 (2C), 116.3 (2C),
109.1, 108.6, 107.9, 105.1, 102.8, 79.2, 76.9, 76.3, 75.7, 74.9, 73.5, 72.5,
70.1, 65.7, 55.7, 53.7, 40.7, 28.1, 27.2, 26.6 (br, 2C), 26.2, 25.4,11.6 ppm;
ESI (m/z, ec): 810.85 [Mꢀ1]ꢀ.
20
[1% H2O/(15% MeOH/THF)] 0.58; [
a
]
¼ꢀ26.00 (c 1.14, H2O); lmax
D
(
3
) (MeOH) 253 (19,485), 432 nm (17,544 Mꢀ1 cmꢀ1); nmax (KBr
disk) 3390 (br), 2921 (br), 1651 (br), 1595, 1557, 1478, 1455, 1309,
1151 (br), 1052 (br) cmꢀ1
dH (200 MHz, DMSO-d6): 9.08e9.04 (2H,
;
m, CONH), 8.05 (4H, d, J 7.6 Hz, AreH), 7.54e7.49 (12H, m, AreH),
7.32e7.26 (4H, m, AreH), 4.89e4.38 (2H, m), 4.34e4.24 (2H, m),
4.10e3.55 (24H, m), 3.46e3.15 (14H, m), 2.98e2.94 (2H, m); dC
(50.3 MHz, DMSO-d6) selected signals for the major isomer: 162.1,
161.4, 141.7, 138.4, 136.7, 130.4 (2C), 129.4 (2C), 126.7, 126.1, 125.0,
119.5 (2C), 116.9 (2C), 103.8, 97.1, 80.0, 75.2, 73.3, 72.8, 71.7, 70.8,
70.3, 69.1, 60.8, 40.7; HRMS (ESI): (m/z, þc): [MþNa]þ, found
654.2015. C28H33N5NaO12 requires 654.2023.
5.1.10. Synthesis of 4-(4,5-dihydro-5-oxo-3-phenylpyrazol-1-yl)ben-
zoic acid 19. In a 50 mL three neck round bottomed flask equipped
with a condenser and a thermometer 4-hydrazynobenzoic acid 17
(1.52 g, 10.0 mmol, 1.1 equiv) was suspended in EtOH (12 mL) at
20 ꢁC. Ethylacetoacetate 18 (1.18 g, 9.10 mmol,1.0 equiv, 1.15 mL) was
added and the resulting mixture was heated to reflux for 2.5 h. After
cooling to 20 ꢁC, the solvent was evaporated under reduced pressure
and the residue was triturated in CH2Cl2 (20 mL). The suspension
was stirred for 1 h and then it was filtered to obtain the title com-
pound (1.71 g, 86%) as off white powder, mp 280e281 ꢁC, lit.25
5.1.13. Synthesis of 4-[(4Z)-4-(2-phenylhydrazono)-4,5-dihydro-3-
methyl-5-oxopyrazol-1-yl]-N-{(2R,3R,4S,5R,6S)-6-[(2R,3S,4R,5R)-tet-
rahydro-4,5,6-trihydroxy-2-(hydroxymethyl)-2H-pyran-3-yloxy]-tet-
rahydro-3,4,5-trihydroxy-2H-pyran-2-yl}methylbenzamide 22. The
synthesis of compound 22 was carried out on a 0.18 mmol scale of
compound 21 (150 mg) using 90% aq TFA13a (2.3 mL) following the
experimental procedure and work-up reported for compound 16, to
isolate the title compound (94 mg, 79%) as orange powder, mp
20
283 ꢁC; Rf (10% MeOH/CH2Cl2) 0.22; lmax
(22,007 Mꢀ1 cmꢀ1); nmax (KBr disk): 3400e2548 (br), 1692e1600
(br), 1513, 1414e1300 (br), 1200, 1150, 1110 cmꢀ1
dH (200 MHz,
DMSO-d6) 8.01e7.99 (2H, m, AreH 19a and 2H, m, ArH 19), 7.94e7.89
(2H, m, AreH 19a and 2H, m, ArH, 19), 5.40 [1H, br s, HC]COH(NPh)
19a], 3.74 [2H, br s, H2CCO(NPh) 19], 2.14 (3H, s, CH3 19a and 3H, s,
CH3 19); dC (50.3 MHz, DMSO-d6þNH4OH) 171.0, 164.4, 148.6, 142.9,
132.1 129.5 (2C), 116.9 (2C), 85.0, 15.1; ESI (m/z, ꢀc): 217.4 [Mꢀ1]ꢀ.
(
3 ) (MeOH) 282 nm
195e196 ꢁC; Rf [1% H2O/(15% MeOH/THF)] 0.29; [
a
]
¼þ27.10 (c
D
1.06, H2O); lmax
(15,793 Mꢀ1 cmꢀ1); nmax (KBr disk) 3369 (br), 2924 (br), 1659e1606
(br), 1553, 1506, 1343, 1273, 1153 (br), 1052 (br) cmꢀ1
dH (200 MHz,
(
3
) (MeOH) 258 (10,114), 274 (13,629), 391 nm
;
;
DMSO-d6): 8.74e8.36 (2H, m, CONH), 8.02e7.91 (8H, m, AreH),
7.63e7.60 (4H, d, J 8.8 Hz, AreH), 7.44e7.42 (4H, m, AreH), 7.22 (2H,
t, J 7.8 Hz, AreH), 4.92e4.87 (1H, m), 4.76e4.72 (1H, m), 4.69e4.52
(2H, m), 4.47e4.30 (2H, m), 4.24e3.51 (20H, m), 3.43e3.06 (16H,
m), 2.98e2.92 (2H, m), 2.30 [6H, s, (CH3)2]; dC (50.3 MHz, DMSO-d6)
selected signals for the major isomer: 166.7, 157.3, 149.7, 141.7,
140.5, 130.8, 130.1 (2C), 128.9 (2C), 128.0, 126.3, 117.2 (2C), 116.7
(2C), 104.2, 97.2, 80.7, 79.7, 75.3 (2C, br), 73.5, 73.1, 70.9, 69.0, 60.8,
43.3, 12.1; HRMS (ESI) (m/z, þc): [MþNa]þ, found 668.2170:
C29H35N5Na O12 requires 668.2180.
5.1.11. Synthesis of 4-[(4Z)-4-(2-phenylhydrazono)-4,5-dihydro-3-
methyl-5-oxopyrazol-1-yl]benzoic acid 20. A 1.25 M solution of so-
dium nitrite (0.17 g, 2.50 mmol, 1.07 equiv) in water was added at
0 ꢁC to aniline 5a (0.23 g, 2.50 mmol, 1.07 equiv) dissolved in 3.2 M
HCl (2.9 mL). The acid solution was stirred for 10 min at 0 ꢁC and
compound 19 (0.51 g, 2.32 mmol,1.0 equiv) dissolved in 0.7 M NaOH
(7 mL) was introduced into the reaction flask. The resulting solution
was stirred for 0.5 h and NaOAc 0.7 M (4.5 mL) was added, leading
5.1.14. Synthesis of 4-(5-hydroxy-3-phenyl-1H-pyrazol-1-yl)benzoic
acid 24a. A 100 mL three neck round bottomed flask equipped with