Synthesis and Characterization of Some 2-(N-benzoyl-N-pyrid-2-yl aminobenzyl)-aminobarbituric acids...

Synthesis and Characterization of Some …….. M. H. Al–Douh , A. A. Al–Fatlawy , O. H. Abid

Journal of Natural and Applied Sciences, Vol. 8 No. 1 – April 2004 181

Synthesis and Characterization of Some 2-(N-benzoyl-N-pyrid-2-yl aminobenzyl)-aminobarbituric acids

via N-benzylidene pyridine-2-amines

Mohammed H. Al-Douh1,*, Ali A. Al-Fatlawy2, and Obaid H. Abid3. 1 Chemistry Dept., Faculty of Education, Hadhramout University of Science and Technology (HUST),

Mukalla, Hadhramout, Republic of Yemen. 2 Chem. Dept., College of Science, Univ. of Babylon, Babylon, Iraq. 3 Chem. Dept., College of Science, Univ. of Baghdad, Baghdad, Iraq. * [email protected] or [email protected].

Abstract

N-Benzylidene pyridine-2-amines (I) [Schiff bases] were prepared by condensation of 2-aminopyridine with aromatic aldehydes in boiling absolute ethanol. The reaction of Schiff bases with benzoyl chloride in dry benzene afforded N-(α-chlorobenzyl)-N-pyrid-2-yl benzamides (II). Guanidine carbonate underwent a nucleophilic substitution reaction with N-(α-chlorobenzyl)-N-pyrid-2-yl benzamides (II) in basic medium to give N-benzoyl-N-pyrid-2-yl aminobenzyl-guanidines (III). Diethyl malonate DEM underwent condensation in basic medium with N-benzoyl-N-pyrid-2-yl aminobenzylguanidines (III) to give 2-(N-benzoyl-N-pyrid-2-yl aminobenzyl)-aminobarbituric acids (IV).

These barbituric acid derivatives were identified by their m.ps, elemental analysis (CHN), IR spectra, UV-Vis. spectra, FTIR spectra, and 1HNMR spectra. The barbituric acid derivatives have long been known to possess hypnotics activity, and it is hoped that our compounds would do so. Keywords: aminopyridines, aminobarbituric acids, Schiff bases and N-benzylidene pyridine-2-

amines. Introduction

Schiff bases of the aromatic type Ar-N=CH-Ar` are prepared by the acid-catalyzed reaction of aromatic aldehydes and primary aromatic amines in boiling ethanol(15–16). These bases are condensed with acid halides to give tertiary amides, which are hydrolyzed to give aldehydes and secondary amide derivatives(5).

N-α-Chlorobenzyl-N-alkyl benzamides are found to undergo substitution reactions

(nucleophilic substitution) when treated with thiourea in basic media in dry acetone(6, 18) to yield α-aminobenzyl-iso-thiourea derivatives.

In 1862, A. V. Baeyer accidentally discovered the barbituric acid (malonylurea) by reaction of

urea with malonic acid in the presence of phosphorus oxychloride POCl3(1). The barbituric acid is a

pyrimidine derivative, which has been used in medicine as soporifics and hypnotics since 1903(3, 17). The target of this work is to prepare new barbituric acid derivatives, which are hoped to have

hypnotic activity.

Experimental Part

A. Analytical Instruments: The melting points were determined with Stuart Melting Point Apparatus. The elemental

analyses [CHN] were carried with Carlo Frba type 1106 CHN elemental Analyzer. IR spectra were



recorded with Perkin-Elmer 1310 Infrared Spectrophotometer, by KBr disks. FTIR spectra were recorded with FTIR-8300 Schimadzu, Single beam, Path Laser, by KBr disk technique. UV-Vis spectra were recorded with Schimadzu Recc-160 Spectrophotometer, in methanol. 1HNMR spectra was recorded with Bruker Spectrospin, Nuclear Magnetic Resonance 80MHz-Sy, in DMSO-d6 as a solvent and with TMS as a reference.

B. Preparation Methods: 1. Synthesis of N-benzylidene pyridine-2-amines (I):

A mixture of equimolar amounts (0.01mol) of the aromatic aldehyde and 2-aminopyridine was dissolved in 15mL of absolute ethanol containing a drop of glacial acetic acid and refluxed in water bath for 1hr. The reaction mixture was then allowed to cool to room temperature, the solid filtered, washed with a little (2%) HCl solution then with distilled water, and re-crystallized from ethanol to yield colored crystals of N-benzylidene pyridine-2-amines (I).

2. Synthesis of N-(α-chlorobenzyl)-N-pyrid-2-yl benzamides (II):

In a 100mL two-necked round bottom flask equipped with a magnetic stirrer, a double surface condenser with calcium chloride guard tube, and a dropping funnel, was dissolved 0.01mol of N-benzylidene pyridine-2-amines (I) in a minimum amount of dry benzene. In the dropping funnel was placed (0.01mol) of benzoyl chloride in equivolume amount of dry benzene. The benzoyl chloride solution was added dropwise to the reaction mixture at 60oC for 1hr with continuous stirring. The solvent was evaporated and the precipitated colored residue was filtered, washed with dilute solution of sodium carbonate (2%) then with distilled water, and re-crystallized from ethanol.

3. Synthesis of N-benzoyl-N-pyrid-2-yl aminobenzylguanidines (III):

In a 100mL round bottom flask equipped with a magnetic stirrer, and a double surface condenser with calcium chloride guard tube was placed a solution of (0.01mol) of N-(α-chlorobenzyl)-N-pyrid-2-yl benzamides (II) in 10mL of absolute ethanol. To a solution of (0.01mol) of guanidine carbonate and (0.01mol) of anhydrous sodium carbonate dissolved in 5mL of absolute ethanol. The reaction mixture was refluxed in water bath at 60oC for 1hr with continuous stirring. The solvent was evaporated and the remaining colored residue of N-benzoyl-N-pyrid-2-yl aminobenzylguanidines (III) was filtered, washed with dilute solution of sodium carbonate (2%) and then with distilled water, and re-crystallized from ethanol-acetone mixture (50%).

4. Synthesis of 2-(N-benzoyl-N-pyrid-2-yl aminobenzyl)-aminobarbituric acid derivatives

(IV): In a 100mL round bottom flask, fitted with a double surface condenser with calcium chloride

guard tube, was placed (0.02mol) of DEM and 10mL of ethanolic solution of sodium ethoxide [prepared by dissolving 0.46gm of dry clean sodium metal in 10mL absolute ethanol] with continuous stirring for 20mins. To this mixture, was added (0.02mol) of N-benzoyl-N-pyrid-2-yl aminobenzylguanidines (III) in 10mL of absolute ethanol heated to 70oC. The resulting mixture was refluxed in an oil bath at 130oC for 8 hrs with continuous stirring. To the cold clear solution was added 20mL of distilled water, and finally acidified with 2mL of concentrated hydrochloric acid. The precipitated colored solid was filtered, washed with distilled water, dried, and re-crystallized from ethanol-acetone mixture (50%).

Results and Discussion

Schiff bases of the pyridine type 2-Py-N=CH-Ar` are prepared by acid catalyzed reaction of aromatic aldehydes and 2-aminopyridine in boiling ethanol(15-16):



+

2-aminopyridine benzaldehydes N-benzylidene pyridine-2-amines (I)

Where: Comp. Ia Ib Ic Id Ie

R H 2-Br 3-Br 4-Br 4-NMe2 It is believed that the reaction follows with tetrahedral mechanism(5–6, 18):

+

benzaldehyde oxonium ion carbocation

+ oxonium ion carbocation 2-aminopyridine

protonated carbinolamine hydronium ion

N-benzylidene pyridine-2-amine (I)

The UV–Vis. spectra of these Schiff bases (I) show absorption maxima at 208–218 nm due to

π π* of the benzene ring, 235–243 nm due to π π* of the –N=CH–Ar, 300–323 nm due to π π* of the pyridine ring(13–14), and 365–472 nm due to n π* of the pyridine ring.

The assigned structure have been confirmed by appearance of N=C absorption band at

1645–1685 cm-1, appearance of C=C–H absorption band at 2930–3040 cm-1, disappearance of C=O absorption band at 1695–1700 cm-1, and disappearance of –NH2 absorption band at 3330 cm-1 for symmetric and 3450 cm-1 for asymmetric.

Schiff bases (I) are identified by their m. ps, elemental analysis (Table 2), UV–Vis. spectra

(Table 1), and IR spectra (Table 3).

N

NH2H

O

R

H

N

NR

EtOH / H+

- H2O

H

O

H

NH2NH

OH

H

OH

CN

H

O N

H

H H

CN

H

O

NH

H

H

- H2O

- H +

N

H

N

H

OH

H

OH



It is found that Schiff bases are nucleophiles and weak bases, so they do not react with simple

allyl, alkyl or benzyl halides, but they react smoothly with the relatively more reactive acid halides such as benzoyl chloride to give N-(α-chlorobenzyl)-N-pyrid-2-yl benzamides (II) in good yields. The suggested mechanism is(5–6, 18):

+

N-benzylidene pyridine-2-amine (I) benzoyl chloride

iminum ion

The nitrogen atom attacks the carbon atom of the carbonyl group displacing the chlorine as a

chloride ion and forming the iminum ion II A, which can be represented by structure II B too. Both structures II A and II B are unfavorable, because the positively charged nitrogen atom in II A and the positively charged carbon atom in II B are linked to two strong electron withdrawing groups(4, 7,

12), and collapse to give the more stable structure II C.

The assigned structure have been confirmed by appearance of C–Cl absorption band at 710–745 cm-1, appearance of >C=O absorption band at 1670–1680 cm-1, appearance of C=C–H absorption band at 2940–2980 cm-1, and disappearance of N=C absorption band at 1645–1685 cm-1.

The UV–Vis. spectra of these benzamides (II) show absorption maxima at 227–230 nm due to

π π* of the benzene ring, 245–265 nm due to π π* of the benzene ring, 271–280 nm due to π π* of the pyridine ring(13–14), and 332–359 nm due to n π* of the pyridine ring.

Benzamides (II) are identified by their m. ps, elemental analysis (Table 4), UV–Vis. spectra

(Table 1), and IR spectra (Table 5). Guanidine is one of the strongest bases in organic chemistry(10–11, 19), where (pKa=13.65) and

give stable equilibrium equation due to the extensive delocalisation of the positive charge on the protonated cation:

guanidine guanidinium ion

It reacts with N-(α-chlorobenzyl)-N-pyrid-2-yl benzamides (II) in dry ethanol, to yield

N-benzoyl-N-pyrid-2-yl aminobenzylguanidinium chlorides, when treated with (2%) Na2CO3 solution, yield N-benzoyl-N-pyrid-2-yl aminobenzyl-guanidines (III):

Cl

O

Bz dry

N H

N

O

Cl

R

N H

N

O

Cl

RII A II B

NH

N

O

Cl R

II C

N

H

N

H +NH2

H2N NH2

NH2

NH2H2NH2N NH2

NH2NH2

H2N NH

N-(α-chlorobenzyl)-N-pyrid-2-yl

benzamides (II)



+

guanidine carbonate

The assigned structure have been confirmed by appearance of –NH2 out–of–plane absorption

band at 1590–1620 cm-1, appearance of –NH2 of 1o symmetric stretching absorption band at 3360–3400 cm-1, appearance of –NH2 of 1o asymmetric stretching absorption band at 3430–3520 cm-1, and disappearance of C–Cl absorption band at 710–745 cm-1.

The UV–Vis. spectra of these guanidines (III) show absorption maxima at 229–235 nm due to

π π* of the benzene ring, 244–249 nm due to π π* of the H-N=C< group, 270–287 nm due to π π* of the pyridine ring(13–14), and 301–366 nm due to n π* of the pyridine ring.

Substituted guanidines (III) are identified by their m. ps, elemental analysis (Table 6),

UV–Vis. spectra (Table 1), IR spectra (Table 7), and FTIR spectra (Table 8). N-Benzoyl-N-pyrid-2-yl aminobenzylguanidines (III) are condensed under basic conditions

(EtONa) with DEM to give the corresponding pyrimidine derivatives, which known as barbituric acid derivatives(8, 17, 19):

+

DEM

(keto form) (enol form)

It is known that DEM decomposes when heated in neutral or acidic medium to acetic acid,

ethanol and CO2, a process called decarboxylation (8–10, 17):

NH

N

O

N

NH2

NH

H

R

NH2

H2N NH2

. H2CO312

N

H

N O

ClR

EtOHNa2CO3

N-(α-chlorobenzyl)-N-pyrid-2-yl

benzamides (II) N-benzoyl-N-pyrid-2-yl

aminobenzylguanidines (III)

O

OH3C

H3C

O

O

NH

N

O

R

N N

N

H

O

O

H

H

1. NaOEt / EtOH2. HCl

NH

N

O

N

NH2

NH

H

R

N H

N

O

R

N N

N

H

O

O

H

N-benzoyl-N-pyrid-2-yl

aminobenzylguanidines (III)



CH3COOH + 2 EtOH + CO2

DEM acetic acid ethanol carbon dioxide

To keep DEM into solution without decomposition, it is converted into the sodium salt with

sodium ethoxide in absolute ethanol(8–10, 17).

DEM sodiomalonic ester

To form the pyrimidine ring, a nucleophilic group (–NH2 or =NH) of guanidine derivative

attacks the electrophilic carbonyl group of DEM, to form 2-(N-benzoyl-N-pyrid-2-yl aminobenzyl)-aminobarbituric acids (IV), via a tetrahedral mechanism similar to that followed in reaction of an amine with an ester(8–10, 17).

The assigned structure have been confirmed by appearance of –CH2– absorption band at

1455.6–1487.0 cm-1, appearance of amide (II) of >C=O absorption band at 1546.3–1565.7 cm-1, appearance of amide (I) of >C=O absorption band at 1674.1–1720.4 cm-1, appearance of symmetric aliphatic C–H absorption band at 2844.5–2858.3 cm-1, appearance of asymmetric aliphatic C–H absorption band at 2922.0–2929.6 cm-1, appearance of >N–H of 2o amine absorption band at 3327.3–3407.4 cm-1, disappearance of –NH2 of 1o amine absorption band at 1590–1620 cm-1, disappearance of –NH2 of 1o symmetric amine absorption band at 3360–3400 cm-1, and disappearance of –NH2 of 1o asymmetric amine absorption band at 3430–3520 cm-1.

The UV–Vis. spectra of these barbituric acid derivatives (IV) show absorption maxima at

226–233 nm due to π π* of the benzene ring, 237–269 nm due to n π* of benzene ring, 280–288 nm due to π π* of the pyridine ring(13–14), and 300–335 nm due to n π* of the pyridine ring.

The 1HNMR spectrum of IVc shows broad singlet signal at δ=3.33 ppm for 2 protons of

methylene group –CH2– of the pyrimidine ring(2, 6, 17–18), one proton of methine group C–H, and one proton of N–Ha group, multiplet signals at δ=7.25–7.45 ppm for benzene, benzoyl and pyridine aromatic rings, and singlet signal at δ=8.78 ppm for one proton of N–Hb group of the pyrimidine ring, (Fig.1).

Barbituric acid derivatives (IV) are identified by their m. ps, elemental analysis (Table 9),

UV–Vis. spectra (Table 1), FTIR spectra (Table 10), and 1HNMR spectrum.

Δ, H2OO

OH3C

H3C

O

O

O

O CH3

CH3

O

O

H

H

Na+OEt-

EtOHNa

O

O CH3

CH3

O

O

H



Table 1: UV-Vis. spectra of N-benzylidene pyridine-2-amines (I), N-(α-chlorobenzyl)-N-pyrid-2-yl

benzamides (II), N-benzoyl-N-pyrid-2-yl aminobenzylguanidines (III), and 2-(N-benzoyl-N-pyrid-2-yl aminobenzyl)-aminobarbituric acids (IV) (nm) in methanol:

Comp. Ia Ib Ic Id Ie

λmax nm 216, 235 246, 265 300, 385

208, 237 254, 271 305, 472

212, 239 245, 265 301, 365

218, 240 258, 280 323, 380

213, 243 268

321, 383 Comp. IIa IIb IIc IId IIe

λmax nm 227, 263 280, 332

230 251, 263

227, 245 258, 343

227, 264 279, 334

230, 265 271, 359

Comp. IIIa IIIb IIIc IIId IIIe

λmax nm 232, 270 285, 327

235 244, 254

229, 249 301, 366

245 287

234, 244 287, 359

Comp. IVa IVb IVc IVd IVe

λmax nm 228 269, 280

226, 237 247, 256,

335

233, 268 288, 300 227 232

244, 253

Table 2: Molecular formula, yields, m. p.oC, color, re-crystallization solvent and elemental analysis

of Schiff bases: N-benzylidene pyridine-2-amines (I):

Comp. M. F. R Yield % m. p. oC Color Re-cryst.

solvent (CHN) C% H% N%

Ia C12H10N2 H 67 91-93 Fit Yellow

Ethanol 75%

Calc. Found

79.09 79.29

5.53 5.77

15.37 15.66

Ib C12H9N2Br 2-Br 73 112-113 White Ethanol 75%

Calc. Found

55.19 55.09

3.47 3.66

10.73 10.12

Ic C12H9N2Br 3-Br 88 33 White Ethanol 75%

Calc. Found

55.19 54.99

3.47 3.29

10.73 11.08

Id C12H9N2Br 4-Br 81 41 Fit Yellow

Ethanol 50%

Calc. Found

55.19 55.43

3.47 3.59

10.73 10.98

Ie C14H15N3 4-NMe2 72 58 Golden Ethanol 50%

Calc. Found

74.64 74.29

6.71 6.82

18.65 18.44

N

N

H

R



Table 3: IR spectra of N-benzylidine pyridine-2-amines (I) (cm-1):

Comp. R ν N=C–Harom.

ν C=C–H arom.

ν C–H aliph.

ν C=N imine

ν C=C arom.

δ C–Harom.

ν C–N arom.

ν N–C aliph.

γ C–H disubst.

Ia H 3180 3010 - 1650 1600-1460 1440 as. 1310

sy. 1280 - 810 740

Ib 2-Br 3125 3030 - 1680 1605-1460 1435 as. 1325

sy. 1210 - 780

Ic 3-Br 3195 3010 - 1645 1585-1445 1425 as. 1315

sy. 1235 - 755

Id 4-Br 3230 3040 - 1685 1595-1470 1445 as. 1310

sy. 1220 - 840

Ie 4-NMe2 3180 2930 as. 2830 sy. 2730 1660 1610-

1430 1420 as. 1375 sy. 1235

as. 1340 sy. 1315 855

Table 4: Molecular formula, yields, M. P.oC, color, re-crystallization solvent and elemental analysis

of N-(α-chlorobenzyl)-N-pyrid-2-yl benzamides (II):

Comp. M. F. R Yield % M. P.°C Color Re-cryst.


IIa C19H15ON2Cl H 97 102-104 White Ethanol 50%

Calc. Found

70.70 70.51

4.68 5.08

8.68 8.51

IIb C19H14ON2ClBr 2-Br 80 96 Fit Yellow

Ethanol 50%

Calc. Found

56.81 57.09

3.51 3.70

6.97 7.05

IIc C19H14ON2ClBr 3-Br 49 107-108 White Ethanol 50%

Calc. Found

56.81 56.53

3.51 3.70

6.97 6.81

IId C19H14ON2ClBr 4-Br 56 88 Fit White

Ethanol 50%

Calc. Found

56.81 56.69

3.51 3.66

6.97 6.81

IIe C21H20ON3Cl 4-NMe2 92 101 Fit Yellow

Ethanol + Acetone

Calc. Found

68.94 69.08

5.51 5.99

11.49 11.29

Table 5: IR spectra of N-(α-chlorobenzyl)-N-pyrid-2-yl benzamides (II) (cm-1):

Comp. R ν N=C–H arom.

ν C=C–H arom.

ν C=C–Hbenzoyl

ν C–Haliph.

ν C=O 3o amide

δ Bz–C=O3o amide

ν C–N arom.

γ C–H disubst.

ν C–Claliph.

IIa H 3060 3025 2965 - 1670 1390 as. 1315 sy. 1290

830 760 715

IIb 2-Br 3070 3010 2975 - 1670 1410 as. 1340 sy. 1290 840 745

IIc 3-Br 3090 3050 2940 - 1680 1430 as. 1340 sy. 1300 820 720

IId 4-Br 3065 3000 2980 - 1670 1400 as. 1335 sy. 1295 800 720

IIe 4-NMe2 3060 3020 2955 as. 2885sy. 2805 1680 1395 as. 1340

sy. 1290 810 710

NH

N

O

Cl R



Table 6: Molecular formula, yields, M. P.oC, color, re-crystallization solvent and elemental analysis

of N-benzoyl-N-pyrid-2-yl aminobenzylguanidines (III):

Comp. M. F. R Yield % M. P. oC Color Re-cryst.


IIIa C20H19ON5 H 87 210-212 White Ethanol + Acetone

Calc. Found

69.55 69.40

5.55 5.69

20.28 20.10

IIIb C20H18ON5Br 2-Br 76 decomp. 230

Fit Yellow

Ethanol + Acetone

Calc. Found

56.61 56.33

4.28 4.40

16.51 16.46

IIIc C20H18ON5Br 3-Br 78 179-181 Fit Yellow

Ethanol + Acetone

Calc. Found

56.61 56.30

4.28 4.37

16.51 16.60

IIId C20H18ON5Br 4-Br 73 102 White Ethanol + Acetone

Calc. Found

56.61 56.70

4.28 4.34

16.51 16.60

IIIe C22H24ON6 4-NMe2 71 decomp. 275 Brown Ethanol +

Acetone Calc.

Found 68.02 68.20

6.23 6.35

21.64 21.45

Table 7: IR spectra of N-benzoyl-N-pyrid-2-yl aminobenzylguanidines (III) (cm-1):

Comp. R ν –NH2 amine 1o

ν N=C–Harom.

ν C=C–Harom.

ν C=C–Hbenzoyl

ν C–H aliph.

ν C=O 3o amide

ν C=NH arom.

δ –NH2 amine 1o

ν C–Haliph.

δ Bz–C=O3o amide

IIIa H as. 3520 sy. 3360 3220 3050 3000 - 1650 1630 1620 1445 1380

IIIb 2-Br as. 3470 sy. 3380 3120 3060 3020 - 1680 1650 1600 1420 1390

IIIc 3-Br as. 3450 sy. 3400 3210 3080 3020 - 1670 1625 1595 1465 1380

IIId 4-Br as. 3430 sy. 3360 3190 3060 3020 - 1695 1630 1610 1460 1330

IIIe 4-NMe2 as. 3440 sy. 3380 3260 3100 3040 as. 2900

sy. 2800 1690 1640 1590 1450 1375

N

HN

O

R

N

H2NNH

H



Table 8: FTIR spectra of N-benzoyl-N-pyrid-2-yl aminobenzylguanidines (cm-1):

Comp. R ν –NH2 amine 1o

ν N=C–H arom.

ν C=C–Harom.

ν C=C–Hbenzoyl

ν C=O 3o amide

ν C=N–Harom.

δ –NH2 amine 1o

ν C–H aliph.

δ Bz–C=O3o amide

ν C–Brarom.

IIIc 3-Br as. 3471.6 sy. 3413.8 3148.2 3074.1 3033.4 1678.0 1637.5 1604.7 1483.2 1398.3 486.0

IIId 4-Br as. 3422.2 sy. 3338.6 3214.8 3062.7 3037.1 1676.0 1601.9 1579.6 1433.0 1375.2 473.2

Table 9: Molecular formula, yields, m. p.oC, color, re-crystallization solvent and elementalanalysis of 2-(N-benzoyl-N-pyrid-2-yl aminobenzyl)-aminobarbituric acids (IV):

Comp. M. F. R Yield % m. p. oC Color Re-cryst.


IVa C23H19O3N5 H 70 decomp. 225-227

Fit Orange

Ethanol + Acetone

Calc. Found

66.82 66.70

4.63 4.51

16.94 17.01

IVb C23H18O3N5Br 2-Br 50 > 300 Dark Pink

Ethanol + Acetone

Calc. Found

56.11 55.88

3.69 3.82

14.23 14.09

IVc C23H18O3N5Br 3-Br 74 126-130 Fit Yellow

Ethanol + Acetone

Calc. Found

56.11 55.99

3.69 3.79

14.23 14.11

IVd C23H18O3N5Br 4-Br 69 > 300 Fit Brown

Ethanol + Acetone

Calc. Found

56.11 56.21

3.69 3.58

14.23 14.16

IVe C25H24O3N6 4-NMe2 85 >300 Fit Yellow

Ethanol + Acetone

Calc. Found

65.78 65.61

5.30 5.19

18.41 18.29

NH

N

O

R

NN

N

H

O

O

H

N

HN

O

R

N

H2NNH

H



Table 10: FTIR spectra of 2-(N-benzoyl-N-pyrid-2-yl aminobenzyl)-aminobarbituric acids (IV)

(cm-1):

Comp. R ν –NH amine 2o

ν N=CHarom.

ν C=C–H arom.

ν C=CHbenzoyl

ν CH2 aliph.

ν C=Oamide I

ν C=O 3o amide

ν C=NHarom.

ν C=O amide II

δ CH2 aliph.

ν C–Haliph.

ν C–Brarom.

IVa H 3327.3 3159.3 3037.0 3007.4 as. 2929.6sy. 2856.4 1677.8 1658.3 1625.9 1553.7 1455.6 1426.9 -

IVb 2-Br 3348.2 3118.5 3066.7 3029.6 as. 2922.0sy. 2852.5 1676.0 1649.0 1611.1 1546.8 1461.9 1427.2 522.7

IVc 3-Br 3407.4 3074.0 3044.4 3025.9 as. 2923.9sy. 2858.3 1720.4 1648.2 1612.0 1550.9 1487.0 1404.1 513.0

IVd 4-Br 3335.0 3074.1 3055.6 3022.2 as. 2925.8sy. 2856.4 1675.9 1650.0 1601.9 1546.3 1471.3 1419.5 449.1

IVe 4-NMe2 3388.9 3185.2 3074.1 3037.0 as. 2925.9sy. 2844.5 1674.1 1645.4 1600.9 1565.7 1461.9 1415.8 -



Fig.1: 1H NMR spectrum of 2-(-N-benzoyl-N-pyrid-2-yl amino-3-bromobenzyl)-aminobarbituric acid IVc (ppm).

NH

N

O

NN

N

Hb

O

O

Ha

Br



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الدوح ، الفتالوي ، الشمري .. أمينوباربيتيوريك-)يل أمينوبنزيل-2-بيريد-N-بنزويل-N(-2 تحضير وتشخيص بعض حوامض

194 2004 أبريل– العدد األول – المجلد الثامن –مجلة جامعة عدن للعلوم الطبيعية والتطبيقية

تحضير وتشخيص بعض حوامض 2-)N-بنزويل-N-أمينوباربيتيوريك -)يل أمينوبنزيل-2-بيريد

أمين-2-بنزيليدين بيريدين-Nبواسطة

3، وعبيد حسن الشمري2، علي عبدالصاحب الفتالوي*،1محمد هادي الدوح .، الجمهورية اليمنيةقسم الكيمياء، آلية التربية، جامعة حضرموت للعلوم والتكنولوجيا، المكال، حضرموت 1 .قسم الكيمياء، آلية العلوم، جامعة بابل، بابل، جمهورية العراق 2 .قسم الكيمياء، آلية العلوم، جامعة بغداد، بغداد، جمهورية العراق 3

*[email protected] أو [email protected].

الخالصة

دين -Nة من حضرت خمس دين بيري ين -2-بنزيلي -N-benzylidene pyridine-2) قواعد شيف (أمamines (I) ي -2 بتكاثف ك . أمينوبيريدين مع األلديهايدات األروماتية في اإليثانول المغل ـف تل حولت قواعد شي

N-(α-chlorobenzyl)-N-pyrid-2-yl benzamidesيل بنزأميـدات-2-بيريد-N-)آلوروبنزيل-N-)αإلى (II) اف زين الج ي البن ل ف د البنزوي ع آلوري ا م ت . بمفاعلته ع وفوعل ضـرة م ـد المح ات الكلوروبنزأمي مرآب

ي ق، لتعط انول المطل ي اإليث ـن ف ـات الجوانيدي ل-Nآربونـ د-N-بنزوي دين -2-بيري ل جواني ل أمينوبنزي -Nيbenzoyl-N-pyrid-2-yl aminobenzylguanidines (III) . رة ـفت األخي م تكاث ات ث ل مالون ائي أثي مع ثن

diethyl malonate [DEM] صوديوم سيد ال ي الكحول في EtONa في وسط قاعدي من إيثوآ ق األثيل المطلشتقــات ل -N(-2 حامض لتعطي م د -N-بنزوي ل -2-بيري ل أمينوبنزي ـك -)ي -N-benzoyl-N)-2أمينوباربيتيوري

pyrid-2-yl aminobenzyl)-aminobarbituric acids (IV). ل العناصر ثبت ات المحضرة وشخصت بتحلي صهار المرآب اط ان اف (CHN)ت نق -IR ،UV وبأطي

Vis. أشعة تحول فوريور التداخلي ،(FTIR) سي ووي المغناطي رنين الن ومن المؤمل أن تكون . 1HNMR وال .لمشتقات هذا الحامض فعالية بيولوجية وأهمية طبية أسوة بمشتقات حامض الباربيتيوريك األخرى

.أمين-2-بنزيليدين بيريدين-N أمينوبيريدين، حامض أمينوباربيتيوريك، قواعد شيف و: مفتاحيةآلمات

Synthesis and Characterization of Some 2-(N-benzoyl-N-pyrid-2-yl aminobenzyl)-aminobarbituric acids...

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