1-Ethyl 4-(1-methylethyl) 2-(1,2,3,4-Tetrahydro-1,3-dimethyl-2,4-dioxopyrimidin-5-yl)butanedioate

Molecules 1997, 2, M7

1-Ethyl 4-(1-methylethyl) 2-(1,2,3,4-Tetrahydro-1,3-dimethyl-2,4-dioxopyrimidin-5-yl)butanedioate

Jin-Cong Zhuo* and Hugo Wyler

Institute of Organic Chemistry, University of Lausanne, BCH, CH-1015 Lausanne-Dorigny, Switzerland.
Fax: ++ 41 21 692 3955 ([email protected])

Received: 1 February 1997 / Published: 15 April 1997

Scheme

The diester 2 was prepared by the addition of iso-propanol to 1 according to the reported procedure [1].

iso-Propanol (1ml) was added to a solution of 1 (293 mg, 1mmol) in CH₂Cl₂ (5 ml). The mixture was left at r.t. for 1h. Evaporation of the solvent under reduced pressure afforded the title compound 2, a colourless oil: 325 mg (100 %).

IR (neat): 3070m, 1730vs, 1705vs, 1660vs, 1640vs, 1480s, 1460s, 1370s, 1300-1140br, 1105vs, 1045s, 1020s, 960s, 935s, 925s, 860s, 780s, 755s.

¹H-NMR (CDCl₃): 7.24 (s, 1H, H-6'); 4.96 (hep, J = 6.5, OCHMe₂); 4.20 and 4.14 (2x dq, J = 11.0, 7.1, CO₂CH₂Me), 3.92 (dd, J = 7.2, 6.8, H-2); 3.39 (s, Me-1'); 3.33 (s, Me-3'); 3.01 (dd, J = 17.1, 6.8, 1H, H-3); 2.73 (dd, J = 17.1, 7.2, 1H, H-3); 1.24 (t, J = 7.1, CO₂CH₂CH₃); 1.22 (d, J = 6.5, 3H, CO₂CH(CH₃)₂); 1.19 (d, J = 6.5, 3H, CO₂CH(CH₃)₂).

¹³C-NMR (CDCl₃): 171.5 (CO₂CH₂Me), 170.7 (CO₂CH(CH₃)₂), 162.1 (C-4'), 151.1 (C-2'), 141.4 (C-6'), 110.1 (C-5'), 67.8 (CO₂CH(CH₃)₂), 61.0 (CO₂CH₂Me), 39.6 (C-2), 36.7 (Me-3'), 35.3 (C-3), 27.6 (Me-1'), 21.4 (CO₂CH(CH₃)₂), 13.7 (CO₂CH₂CH₃).

EI-MS: 327 (M+H⁺, 2), 326 (M⁺, 8), 281(3), 280 (13), 267 (16), 266 (9), 252 (2), 239 (24), 238 (60), 237 (22), 210 (32), 194 (12), 193 (100), 169 (7), 167 (34), 166 (45), 165 (27), 110 (26), 81 (47), 80 (25), 69 (7), 68 (11), 56 (5).

Acknowledgment: We thank the Swiss National Foundation for financial support.

References

1. Zhuo, J.-C.; Wyler, H. Helv. Chim. Acta 1993, 76, 1916.

Sample Availability: Available from MDPI, 0.3g, MDPI 10057.