Tgp chi phdn tich Hda. Ly vd Sinh hgc -
ANALYSIS OF NMR SPECTRA OF BENZALDEHYDE HEPTA-O-ACETYL-p- LACTOSYL
Din tda sogn 25 -4 - 2013 Nguyen Dinh Tbanh
Faculty of Chemistry, College of Science, Hanoi National University Hoang Thj Kim Van
Truang Dgi hgc Cdng nghiep Viit Tri (Phu Thg)
TOM TAT
PHAN TiCH PHO NMR CUA CAC BENZALDEHYD HEPTA -0-ACETYL-|3- LACTOSYL THIOSEMICARBAZON
Phd 'H vd " C NMR cia cdc benzaldehyd (peracetyl-fi-lactosyl)thiosemicarbazone dd dugc thdo ludn. Cdc tin hiiu cdng huang tir trong phd NMR cita chiing chl ra mdi quan hi giita cdu true vd vi tri ciia nhdm the theo tuang quan Hammett. Cdu hlnh fi cua cdc thiosemicarbazone ndy dugc xdc nhdn dua vdo hdng sd ghep cap J = 9.0-8.5 Hz giua proton NH-4 ciia lien kit thiosemlcarbazon vd proton H-1' trong hgp phdn lactosyl
INTRODUCTION
The synthetic method of hepta-O-acetyl- P-lactosyl-thiosemicarbazones has been reported previously using microwave- assisted method [1]. In previous articles we armounced the synthesis and prpperties of another aldehyde/ketone
glycosyl per-0-acetylated thiosemicarbazones [2]. There are several
discussions hereui about the influence of strucnu-al factors to the positions of resonance signals m their ' H and '^C NMR spectta of hepta-0-acetyl-P- lactosyO-thiosemicarbazones of
benzaldehydes and acetophenones.
EXPEREVENTAL PART
Substituted acetophenone hepta-0- acetyl-p-lactosyl thiosemicarbazones 1 (Scheme 1) were synthesized in bellow procedure [1]. Theu ' H and ''C NMR spectta was recorded on FT-NMR Avance AV500 Specttometer (Bruker, Germany) at 500.13 MHz and 125.76 MHZ, respectively, using DMSO-rfs as solvent and TMS as an intemal standard.
Specttal data of ' H and '^C NMR were summarized in Tables 1 and 2.
68
General procedure for substituted benzaldehyde (hepta-O-acetyl-fi- lactosyl)-thtosemicarbazones (3LB a-y).
A mixture of hepta-0-acetyl-p-maltosyl thiosemicarbazide IL (1 mmol), benzaldehyde 2a-v (1 mmol), glacial acetic acid (0.5 ml) in absolute ethanol (in the presence of glacial acetic acid as catalyst) or glacial acetic acid (20 ml) was heated at reflux using domestic microwave oven TIFANY 750W in 5-7 min. The solvent was evaporated to one half the original volumes. The resulting colorless crystals were filtered by suction. The crude product when recrystallized from 96% ethanol to afford the title compounds 3 LB a-v.
RESULTS AND DISCUSSION The selected ' H and '^C NMR spectral data of benzaldehyde hepta-O-acetyl-P- lactosyl thiosemicarbazones 3LB a-v were listed in Table 1 and 2. From Tables 1 and 2 it's shown that protons and carbon-13 atoms in these molecules have proper resonance signals in coresponding specttal regions which are characteristic for each atom type.
Protons in NH-2 and NH-4 groups have signal at 6=12.18-11.67 ppm (singlet) and 8=8.88-8.06 ppm (doublet, ^=9.5- 9.0 HZ), respectively. Proton of azomethin group (CH=N) shows chemical shift at 5=8.53-8.00 ppm (singlet). Aromatic protons have resonance signals in region at 6=8.33-
6.27 ppm, and the multicity of these signals depend on substituted pattems in benzene rmgs. Protons in CH3 group in acetate functions have signals in region at 5=2.06-1.92 ppm. Protons of disaccharide component have signals including in range fi-om 5.90 ppm to 3.93 ppm. Protons on C-1" and C-2" carbon in pyranose ring A magnetically interact each to other with coupling constant, in this case, 'J= 8.0-7.0 Hz that indicated that these both protons on C-1" and C-2"
positions have trans-typt interaction.
This one comfirm that Imkage between two pyranose rings, glucopyranose and galactopyranose, in this disaccharide is P-(l—>4)-glycoside bond that completely agree with the stmcture of p-lactose. The distinct stucture pattern of galactopyranose ring, compared with the one of glucopyranose ring, is confirmed by coupling constant between H-4" and H-3" protons with V=3.75-2.5 Hz in galactopyranose ring, compared with the coupling constant V=9.75-9.25 Hz in glucopyranose ring. Protons on C-l' and C-2' carbon atoms in ring B have similar interaction with coupling constant V=9.0-8.5 Hz, m relation to H-H interaction of trans type, therefore, thiosemicarbazide linkage group is equatorial duection, i.e. all benzaldehyde hepta-O-acetyl-p -lactosyl
thiosemicarbazones 3LB a-v have p- anomeric configuration [4]. Other subriments (hydroxy, methyl or methoxy)
69
also have specificsignals. The ^C-NMR spectta of compound 3LB a-v showed the regions at 8 179.1-177.3 ppm (C=S), 170.2-169.0 ppm (C=0 ester), 144.1- 138.9 ppm (azomethine CH=N), 146.4-
122.9 ppm (aromatic carbon atoms), 100.1-60.9 ppm (carbon atoms in lactose component), and 21.2-20.1 ppm (methyl carbon atoms in acetate groups). (Table 3).
«3 OAO ^ ° * = S ^ ^ ^ O
EtOH solv , aceitc acid cat., MW oven
OAc
nng E ring A
3LBa-v
where. R = 4-NOj {3B-a). S-NO^ {3B-b), 2-NO2 (3B-c), 4-F (3B-d), 2,4-diCt {3B-e). 4-CI {3B-f), 3-CI (3B-g).
2-CI (3B-h), 4-Br (3B-i), 2-OH-5-Br (3B-j), H (3B-k), 4-Me (3B-1), 4-iPr (3B-m), 4-OMe {3B-n), 3-OMe (3B-D). 2-OMe (3B-p), 4-OH {3B-q), 3-OH {3B-r), 2-OH (3B-s). 3-OMe-4-OH (3B-t).
3-OEt-^OH {3B-U), 4-NMe2 {3B.V)
Scheme I. Synthesis of benzaldehyde (hepta-O-acetyl-P-lactosyl)thiosemicarbazones.
The H - C long-ranged mteraction in HMBC spectrum of thiosemicarbazone molecule 3LB-r is shown in scheme bellow:
NH—C NH—N
3LB-r(R=3-OMe):
Homonuclear ' H - ' H interactions m COSY spectmm in compound 3LB-r are as follows:NH-2(l 1.95)oH-
l'(5.79)oH-2'(5.19)«.H-3'(5.3l)<->H- 4'(3.81><^H-5'(3.88)«.H-6'b(4.07)oH- 6'a(4.30);H-l"(4.79)<->H-2"(4.88)oH- 3"(5.15)oH-4-(5.24); H-5"(4.24)<-s.H- 6"a(4.03) va H-6"b(4.03); H- 2'"(7.44)<^H-5'"(7.34) va H-6"'(7.3I);
70
H-4"'(7.00>oH-5"'(7.34). The positions of resonance signals of protons NH-2, NH-4 and CH=N in compounds 3LB a-v (Fig. 2 A, B and C) had Imear regression expressions as follows, respectively:
8sH.2 = 0.298CJ + 11.903 (R^ = 0.96) 5NH.4 = 0.308CJ +8.621 (R^=0.93) 5cH-N = 0.1450 + 8.065 (R^ = 0.77)
Table I. Selected'H NMR spectra of substituted benzaldehyde (hepta-0-acetyl-P-lactosyl)thiosemicarbazones [S(ppm), multicity, J (Hz)f
R Prolon
NII-2 NlI-4 CH=N I I - 2 ' "
H - 3 ' "
11-4'"
II-.S"' H-O'"
i i - r 11-2' H-3' H-4' H-5' H.6'a H-6'b II 1"
H-2"
11-3"
H-4"
i l - 5 "
»-6"«
li-6'li
corH,
4-NO, 3LB-a I 2 l 6 , s 8.88,d,9.0
8.18.S 8.10.d,9.0 8.25,d,9.0 8 25,d.9.0
-
8.IO,d,9.0 5.88,1,9.0 524-5.21,m
5.31,1,9.25 3.81.1.9.25 3.90-3.87,in
4.31,d,11.5 4.07.dd,5.5.12.5
4.80.d.8.0 4.88,1,8.75 5.15,dd,3.5,10.0
5.24-5.21,ni 4.25,1,6 5 4.03.d,6.0 4.03.d,6.0 2.11-2.01
3-NOi 3LB-b 12.I0,S 8.83,d,9.0
8.21,s 8.58.S
8.30.d,7.5 7.72.1,8 0 8.24.dd.l.5.8.0
5.86.1,9.0 5.20,1.9,5 5.31,1,9,0 3 82,1,9.25 3.91-3.84,m 4.3 l,d, 11.0 4.08,dd,5.5,l2.0
4.80,d,8.0 4.88,dd,8.25,l0 25
5.15,dd,3.S,10O 5.24,d,3.5 4.25.1,6.75 4.03,dd,2.25.6.75 4.03,dd,2.25,6.75 2.11-1.91
4-F 3LB-d 11.90,s 8.66,d,9.0
8 09.S 7.88.d,5.5.8.5
8.IO.d.8.5 8.10,d,8.S
-
7.88,d,5.5,8.5 5.85,1.9.25 5.19.'H.9.25
5.30.d,9.25 3.81.1.9.5 3,90-3.87.m
4,31.d.I1.5 4.07,dd,5.5,ll.O
4.80,d,8.0 4.88,dd,3.25,l0.5 5.17,dd.3.75,9.75 5.24.d.3.5 4.25,t,6 5 4.04-J|.02,ni 4.04^.02,m 2.11-2.01
4-Cl 3LB-f 11.95,s 8.70.d,9.0
8.08,s 7.85,d.8.5 7.49,d.8.5 7.49,d.S.5
-
7.85,d.8.5 5.85.1.9.0 5.20.1,9.25 5,30,1,9.25 3.80,1,9.5 3.90-3.88,111 4.30,d,ll.5 4,08^.05,m 4.80,d,7.5 4.88,1,9.0 5,16,dd,3.5,10.0
5.24,d,3.5 4 25.1,6.0 4.04^.03.111 4 . 0 4 ^ 03,m 2.11-1.91
3-Cl 3LB-g 11.99,5 8.75,d,9.0
8.08,s 7.98,s 7.48-7.44,m
-
7.48-7.44,m 7.70,dd,7.0,1.5
5.85.1,9.0 5.21,1.9.25 5,30,1,9.0 3,81,1,9.5 3.89,ddd, 1.5,5.5,10.0 4 31,d,ll.O 4.07,5.75,12.25
4.80,d,8.0 4.88,dd,2.0.8.0 5.16.dd.3.5.10.0 5.24,d.3,5 4.25.1,6.75 4.04-4.00,m 4.04.^.00,m 2,11-1 90
4-Br 3LB-i 12.00.S 8.70,d,9.0
8.08,5 7.82,d,8.S 7.66,d,8,5
-
7.66,d,8.5 7.82,d,8.5 5.90.1,9.0 5.24.1.9.25 5.33.1,9.25 3,84,1,9.75 3.84,1,9.75 4.33,d,U.O 4.09,dd,5.5,12.0
4.83,d,8.0 4.9l,dd,3.0,ll.5 5.16,dd,3.75,10.25
5.28,d,3.5 4.29,1,6.5 4.07-4.05,111 3 94-3.91,m 2.IS-I.94
II 3LB-k 11.95,5 8.67,d,9.5
8,IO,s 7.82-7.80,111 7.45-7.43,m 7 45-7.43.111 7.45-7.43,111 1 7.82-7.80,ni
5.86,1,9.25 5,19.1.9-5 5.31,1,9.25 3.80,1,9.5 3.89,ddd, 1.75.5.75,9.75
4.30,d,n.O 4.07,dd,5.5,12.0
4.80,d,8.0 4.87.dd,3.0,10.0 5,15,dd.3.5.10.5 5.24,d,3.5 4,26,1,6.75 4.04,dd,2,25,6.25 4.04,dd,2 25.6.25 2.11-1.90
Table I (continuing). Selected 'H NMR spectra of substituted benzaldehyde (hepta-O-acetyl-p-lactosyl)thiosemicarbazones [S(ppm). multicity, J (Hz)]
R Proton
NII-2 N I M C'H-N II-2'"
H-3'"
11-4"
11-5'"
H-6'"
I l - I ' II-2' H-3' H-4' II-5' II-6'a Il-6'b 11-1"
II-2"
11-3"
11-4"
H-5"
ll-6"a H-6"ll C O C / / , Other protons
4-Me 3LB-i 11 86.S 8 59,d.9 5 8.06,5 7,69,d,8,5 7.25,d,8.5 7.25,d,8.5
-
7,69,d,8,5 5.84,1,9,0 5,21,1,9.25 5.30,1.9.25 3.81.1,9.5 3.90-3.87.111 4.30,d,11.0 4.07,dd,S,75,12.25
4.80,d.8.0 4,88,1,9,0 5,l5,dd,3.75,10.25
5.24,d.3.5 4,25.1,6,5 4.04-4,03,111 4.04-4.03,in 2.11-1.90 2.34,s,4"'-Me
4-JPr 31,1)111 11 87,5 8.57,d,9.0 8.09,5 7,72,d,8,0 7.30.d,8.0 7.30,d,8.5
-
7.72,d,8,0 5 83,1,9.25 5 18.1.9 5 5.30,1,9.25 3.81,1,9.25 3.88-3,87,111
4.30,d,11.5 4.09-4.03.111
4.80.d,8.0 4.88,1,9,75 5.l5.dd.l0.5,3.75
5.24.d.3.5 4.25,1,5.75 4.09-4.03,m 4.09-4.03,111 2,11-1.90 2.92,q.7.0,4-"-C//(CH,)j;
1.21,d,7.0.4"'-C//(CH,)2
4-OMe 3LB-n 11.81,5 8,55,d,9.0
8.05.S 7.75,d,8.5 6.99,d,8,5 6.99,d,8.5
-
7.75,d,8.5 5.83,1,9.25 5.18A9.25 5.30,1,9,0 3.82-3.79,m 3,89-3.87.ni 4.30,d,ll,5 4,09^.05,m 4.80,d,7,5 4,88,1,9.25 5.15.dd,10.0.3,0
5.24,d.3.0 4.24.1,6.75 4,04-4,03,111 4,04-4.03,111 2.11-1.91 3.Sl,s,4"'-OMe
3-OMc 3LB-0 11.95,5 S,62,d,9,0
8.07,5 7,44,5 7.00.dd. 1,5.8.0
-
7.14,1,8 0 7.31.1,8.0 5.79,1,9.0 5.18.1,9.25 5.31,1,9.25 3.81,1,9,0 3.88,ddd,3.5,5,5, 10,0
4 3O.d,ll,0 4.07,dd,12.5,6.75
4.79.d,7.5 4.88.dd,10.0.3.0 5.15,dd,10,5,3.5 5.24,d,3,5 4,24,1,6,75 4,03,d,6,5 4,03,d,6.5 2.11-2.01 3.83,5,3"'-OMe
4-OH 3LB-q 11.76,5 8.5I,d,9,5
8.00,5 6,81,d.8,5 7.64,d,8.5 7.64,d.8,5
-
6.8I,d,8.5 5.83.1.9.25 5.18.1,9 25 5,30,1,9,25 3.89-3.86,111
3,80,1,9,75 4.30,d,11.0 4.06,dd,5.5,9.5
4,80,d,8,0 4.87,dd,10.0,3,0 5,l6,dd,10,0,4.0 5.24.d.3.5 4,25,1,6,75 4.03^.02.111 4,03^.02.111 2.11-1.90 9.97,5,4"'-OH
4-NMe, 31.B-V 11.67,5 841,d,9,5
7.97,5 7.59,d,8 5 6.72,d,S,5 6.72,d,8,5
-
7.59,d,8,5 5.82,1,9.0 5.17-5.14,111
5,30.1.9.0 3.81,1.9.25 3.88-3.85.111
4.30.d.ll.O
4.09^.05,111 1 4.79,d.7.5
4,88,1,9.0 5.17-5,14,111,
5.25,d,2.5 4,25.1.6.0 4.04-4.03.111 4.04-4.03.111 2.11-1 91 2.97,s,6H,4"'-N(Me),
1 R t iiclion
C^S COCHj
CH-N C - F "
C-2'"
C-i~
<:-4'"
C-5'"
C-6'"
c-r c-2'
C-3' C-4' C-5' ( - 6 ' C - l "
C-2"
C-3"
C-4"
C-5"
C-6"
COCII,
Table 2. Selected
4-NO, 3LB-a 178.8 170.2- 169 0 141.1 140.2 128.4 123,8 147.8 121.8 128.4 81.3 71.2 72.8 76 0 73,4 62,4 99 6 68 9 704 67,1 69.7 610 20,7- 20.3
3-NO2 3LB-b 178.7 170.2- 69.1 141.6 135.7 121.9 1484 1244 130.2 1334 81.3 71.1 72,7 76.0 73,5 624 99 6 68 9 70,4 67.1 69.8 610 20.7- 20,3
Not
C NMR spectra of substituted benzaldehyde (hept
4-K 3LB-d
1784 170,2- 169.1 142,6
no4
129.7 115.7 163.3 115.7 129.7 81,3 71,1 72,7 76,0 7.1,4 6 2 4 99.6 68,9 70,4 67.1 69.8 61.0 20.7- 20.2
?: Other 6(
55,2,4
4-CI 3i,B-r
178,3 170,5- 169.4 142,7 132.5 129.8 128,8 134,9 128,8 129,8 81,2 70.9 72,6 75,9 73,5 62.2 99.6 68 8 70,3 67 0 69,7 60 9 20.5- 20,1
3-CI 3I.B-g
178.6 170,1- 169,0 142.2 135.9 126.3 133.7 130.5 129,8 1267 81.3 71.1 72,7 76,0 73,4 62 3 99 6 68 9 704 67.1 69.7 61.0 20,8- 20.2
4-Br 3LB-i 1784 170.2- 169,0 142,5 133,0 1294 131,7 123,5 131,7 129,4 81.2 71.1 72.7 76.0 73 4 6 2 4 99.6 68.8 704 67.1 69.7 60.9 20,7- 20,4
H 3LB-k
178.3 170.3- 169,1 143,7 133,7 128.7 127 6 130.3 127.6 128.7 81,2 71,1 72,7 76,1 733 6 2 4 99.6 68.8 70,4 67,1 69,7 6! 0 20.7-
20.3
a-0-acetyl-/3-lactosyl)thiosemicarbazones, 5 (ppm)
4-Me 3LB-1 178.2 170,2- 169.0 143,9 131,0 127,5 129.3 140,2 129,3 127,5 812 71,1 72,7 76,0 734 62,3 99 6 68,9 70,4 67 1 69,7 60.9 20,6- 20,2
4-iPr 3LB-m
178,2 170,2- 169,0 143.8 1314 127.6 126.6 150,9 126 6 127,6 81,1 71,0 72,7 76,0 7 3 4 62.3 99.6 68.8 70.3 67,1 69,7 60,9 20,6- 20,2
4-OMe 3LB-n 177.8 170.5- 1694 144,1 126.0 129.2 114.2 161.1 114.2 129.2 81.1 70.9 72.6 75.9 73,5 62,2 99.6 68.8 70.3 67.1 69.7 60.9 20.5- 20.1
3-OMe 3LB-0 1784 170.2- 169.0 143.5 135.1 1114 159.6 116.5 129.6 120,7 81.2 70.9 72.5 76.1 7 3 4 62.3 99,6 68.8 7 0 4 67.1 6 9 7 60.9 20.6- 20.2
4-OH 3LB-q 177.7 170.2- 169.0 144.1 124.6 129.4 115.6 159.6 115.6 1294 81.1 71,1 72.7 76.1 73.3 62.3 99.6 68.8 70.3 67.1 69.7 60 9 20.7- 20,3
' C): 21,0,4"'-Mc (3LB-I); 33,4,5,4"'-Cl l(Me)2; 23.5,4"'-CI l(Mc)2 (3LB-m);
"-OCH, ( 5LB-n); 5 ),2,3"'-OC H3 (3LB-J); 40.0,4' ' - N ( M e ) 2 ( 3 L B - V ) ,
4-NMe, 3l,B-v 177.3 170.2- -
169.0 144.8 120.8 128,9 II I. 6 1517 1116 128,9 81,1 71,0 72,7 76 1 734 62,3 99,6 68 9 704 67.1 69.7 60.9 20.6- 20,2
Conversely, carbon atom in imme group were affected clearly by these substituents with opposite ttend: the donating ones (with a < 0, such as 4-OH, 4-OMe, 4-Me on benzene ring of benzadehyde) caused signal to be shifted to upfield region, and the withdrawing ones (with a < 0, such as 3-N02-4-C1, 4-
NO2, 3-N02-4-Me, 3-N02-4-0Me, 4-Cl, 4-Br in benzadehyde series) caused the resonance of this carbon atom to be in downfield region (Table 3). These tendencies could be shown in equations as follows (Fig. 2D).
6cH-N = -2.4580-1-143.31 (R^ = 0.9I)
A
..„.
12 2
12
< - i p ^ ! / ' 3-CW«-4-OH V ^
v i - O E l - 4 - O H w « . P P m
4 - B I / ' a-F V > 3 - C I
3-DMe
•S,^, = 0 2 9 8 -1 ' R ' = 0 96
/ j - N O ,
1 1 9 0 3
o e -06 -04 -0.2 0 02 04
8
A ! / S 9
S S
8.7
4 - N I . = ^ 4 - O M ^ / T ^ i P ,
y / s - O M e - a - O H / S - O E t ^ - t ^ ^
8 N M . » . P P " ! j < * - N O j / J - N O ,
4 - B r ^ < 3 - a 4 - F / * a
3-OMe
. i „ = 0 3 0 8 c! -t 8 6 2 1 R" = 0 9 3
-1 - 0 8 - 0 6 - 0 4 J.2 0 02 0^4 06 06 Hartimett'sa c
4-NMe, 8.2E
B I
B I S
4 ' ^ ' ! * ' * '
j - ^ - O H « X " ^ /a-OMn
i-OEi-4-ott as
^ ^ t « o .
• ^ a - « = 0 145 n * 8 0 6 5 R ' = 0 7 7
146 145.5
• \ . B - 0 E I - 4 - 0 H
4.«»., x ^ l ' . ' • ' "
a-OH ' ^ i t f j«3 3-OMe-a-OH / • ^ r
143 142.5
4-OH S C H M P P "
••>™=« = - 2 - ' ' 5 8 o - * 143 31 R'
^a-Me - • 4 - I P r
"^
,.^x*4-a
^ ^
j - a ^= 091
" \ . 3 - » I O , -NO, •
Figure 2. Linear relationships between S\H-2 (A), SSH-4 (B), <5r//=.v (C) vd SC=N (D) and Hammett's G in compouds 3LBa-v
CONCLUSIONS signals in their NMR spectra show the The ' H and '"^C NMR spectra of relationships between the structural substituted benzaldehyde peracetyled p- features and positions of the substituted lactosyl)thiosemicarbazones have been groups in benzene ring.
studied and discussed. The magnetic 74
Acknowledgments. Financial support for this work was provided by Vietnam's National Foundation for Science and Technology Development (NAFOSTED).
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