Molbank 2004, M359

http://www.mdpi.net/molbank/

กก

1,3-Diethyl-5-(2-methoxybenzylidene)-2-thioxodihydropyrimidine-4,6(1H,5H)-dione

 

Abdullah Mohamed Asiria*, Khaled Ahmed Alamrya Abraham F. Jalboutb,c and Suhong Zhangb

 

aChemistry Department, Faculty of Science, King Abdul-Aziz University, Jeddah 21413, P.O. Box 9028, Saudi Arabia. Tel.+966-2-6952293, Fax +966-2-6952293, E-mail: aasiri2@kaau.edu.sa 

bDepartment of Physics, Dillard University, New Orleans, LA 70112, USA 

cEJMAPS Organization, 1107 Carrolton Ave., Metairie, LA 70005, USA

 

Received: 13 September 2003 / Accepted:  24 October 2003 / Published: 24 February 2004

กก

  

 

1,3-Diethyl-5-(2-methoxybenzylidene)-2-thioxodihydropyrimidine-4,6(1H,5H)-dione 3 was prepared by Knoevenagel condensation of 2-methoxybenzaldehyde 1 and N,N-diethylthiobarbituric acid 2 in ethanol using piperidine as a base [1,2].

 

            N,N-Diethylthiobarbituric acid 2 ( 1.50 g, 7.5 mmol)  and 2-methoxybenzaldehyde 1 (1.02 g, 0.02 mol ) in ethanol ( 30 mL) were heated under reflux for five minutes. Piperidine (0.5 mL) was added in one portion and the reflux was continued for two hours. The reaction mixture was cooled to room temperature and the solid formed was filtered, washed with cold ethanol ( 2x 20 mL) and dried. 1,3-Diethyl-5-(2-methoxybenzylidene)-2-thioxodihydropyrimidine-4,6(1H,5H)-dione 3 was  recrystallized from ethanol as deep yellow crystals (2.03 g, 85%). 

 

 

M.p. 108 ºC (recrystallized from EtOH, uncorrected).

 

UV lmax (nm; CHCl3)/e (dm3.mol-1.cm-1) 406/16000 and 253/ 6060.

 

IR nmax ( KBr) cm-1 2980, 1674 (C=O), 1632 (C=C), 1391 (CS).

Theoretical (cm-1, AM1)= 1675.4, 1391.4, 1599.8

 

1H-NMR (400 MHz; CDCL3; Me4Si) d 8.90 (1H, s, CH=C), 8.10 (1H, d, J = 7.84 Hz ), 7.5 (1H, d, J = 7.24 Hz, J = 7.14 Hz  ), 7.02 (1H, t(dd), J= 7.6 Hz), 6.94 (1H, d, J = 8.42 Hz ), 4.51, 4.50 ( 4H, t, CH2),3.99 ( 3H, s, CH3O), 1.33, 1.28 ( 6H, q, CH3).

 

13C-NMR (100 MHz, CDCL3; Me4Si) d 179 (C=S), 157.04, 155.6 (2xC=O), 148.16 (CH oliefinc), 134.4, 132.1, 122.5, 120.8, 119.2, 109.9, 43.7, 43.73 (CH2), 13.3, 13.1 (CH3).

 

Anal.Calc. for C16H18N2O3S ( 318.392): C 60.36, H 5.70 , N 10.07; found : C 60.21, H 5.82, N 10.16.

           

References

 

1. G. Jones, Org. React., 1967, 15, 204-599.

2. K. Tanaka, X. Chen and F. Yoneda, Tetrahedron, 1988, 44, 3241-3249.

© 2004 MDPI. All rights reserved.