4-Pyrimidinecarboxylic acid, 5-fluoro-1,2,3,6-tetrahydro-2, 6-dioxo-, methyl ester synthesis

Yield:1996-54-9 70%

Reaction Conditions:

Stage #1: 5-fluoroorotic acidwith 1,8-diazabicyclo[5.4.0]undec-7-ene in N,N-dimethyl-d₆-formamide at 20; for 1 h;
Stage #2: methyl iodide in N,N-dimethyl-formamide at 60; for 4 h;

Steps:

1.1 1.1. Synthesis of Compound 2: English name is methyl5-fluoro-2,6-dioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylate;

Dissolve 5-fluoroorotic acid (Compound 1) (40g, 0.23mol) in N,N-dimethylformamide (500mL). Slowly add DBU (35.0g, 0.23mol) dropwise, stir at room temperature for 1h, then slowly drop iodomethane (32.0g, 0.23mol), and stir at 60 °C for 4h. After the reaction was completed, 100 mL of ice water was added with stirring to precipitate a solid, which was filtered, and the filter cake was washed with water (100 mL x 3) and dried in vacuo to obtain compound 2 (30 g, yield = 70%).

References:

CN110950868,2020,A Location in patent:Paragraph 0062-0067