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

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 2-methoxyethanol to 1 according to the reported procedure [1].

2-Methoxyethanol (0.16 ml, 2 mmol) was added to a solution of 1 (293 mg, 1 mmol) in CH₂Cl₂ (5 ml). The mixture was left at r.t. for 30 min and filtered through a pad of silica gel (EtOAc) afforded the title compound 2, a colourless oil: 340 mg (99 %).

IR (neat): 3070m, 1733vs, 1702vs, 1660vs, 1640vs, 1480s, 1460s, 1375s, 1345s, 1270s, 1255s, 1155s, 1128s, 1095s, 1030s, 920s, 860s, 780s, 755s.

¹H-NMR (CDCl₃): 7.26 (s, 1H, H-6'); 4.24 and 4.20 (2x dt, J = 12.0, 4.6, CO₂CH₂CH₂OMe); 4.20 and 4.17 (2x dq, J = 11.0, 7.1, CO₂CH₂Me), 3.91 (dd, J = 7.8, 6.0, H-2); 3.58 (t, J = 4.6, CO₂CH₂CH₂OMe); 3.40 (s, Me-1'); 3.37 (OMe); 3.34 (s, Me-3'); 3.12 (dd, J = 17.2, 6.0, 1H, H-3); 2.86 (dd, J = 17.2, 7.8, 1H, H-3); 1.24 (t, J = 7.1, CO₂CH₂Me).

¹³C-NMR (CDCl₃): 171.1 (C-4), 171.0 (C-1), 161.9 (C-4'), 151.0 (C-2'), 141.6 (C-6'), 109.7 (C-5'), 69.7 (OCH₂CH₂OMe), 63.2 (OCH₂CH₂OMe), 60.8 (CO₂CH₂Me), 58.3 (OCH₃), 39.7 (C-2), 36.5 (Me-3'), 34.7 (C-3), 27.4 (Me-1'), 13.5 (CO₂CH₂CH₃).

EI-MS: 342 (M⁺, 4), 297(7), 296 (20), 268 (19), 267 (8), 266 (17), 239 (8), 238 (33), 237 (14), 194 (15), 193 (100), 167 (8), 166 (26), 165 (19), 110 (5), 81 (28), 80 (15), 69 (4), 68 (7), 59 (29), 56 (2).

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 10055.

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