4892-02-8

67-56-1

147-93-3

4892-02-8

Example 1: Preparation of methyl 2-[6-(1-bromo-ethyl)-5-fluoropyrimidin-4-yl-thioalkyl]benzoate (Preparation of compounds of formula 2 with o-CO2CH3 substitution); Step 1) Preparation of methyl 2-mercaptobenzoate: 40 g of 2-mercaptobenzoic acid was dissolved in 600 mL of methanol, and cooled to 5°C. 42 mL of concentrated sulfuric acid was added slowly and dropwise over a 10 minute period. The reaction mixture was reacted under reflux conditions for 14 hours and then concentrated under reduced pressure. The concentrate was diluted with 400 mL of dichloromethane and 400 mL of pure water and the organic layer was subsequently separated. The organic layer was washed sequentially with 200 mL of saturated sodium bicarbonate solution and 400 mL of saturated brine, and then dried with anhydrous sodium sulfate. After drying, the organic layer was concentrated to give the crude product, which was further purified by fractional distillation (118°C/7 mmHg). Finally, 42 g (yield: 96%) of methyl thiosalicylate was obtained as a clear oil.1H-NMR (200 MHz, CDCl3) δ (ppm): 8.01 (d, 1H), 7.30 (d, 2H), 7.14 (m, 1H), 4.68 (s, 1H), 3.91 (s, 3H).