2-N-PROPYLTHIAZOLE synthesis

Yield: 84%

Reaction Conditions:

Stage #1:propyl bromide with magnesium in tetrahydrofuran at 35 - 40; for 2 h;Inert atmosphere;
Stage #2:2-(methanesulfonyl)thiazole in tetrahydrofuran at 0 - 20; for 1 h;Inert atmosphere;

Steps:

4 Preparation of 2-propylthiazole:
Disperse 25 g of magnesium chips in 500 mL of THF, and replace the system with nitrogen. At room temperature, add 23g of bromopropane, stir and wait for Grignard initiation; after initiation, continue to add dropwise a mixture of 100g of bromopropane and 200mL of THF, control the dropping rate, and keep the internal temperature between 3540. After the addition is complete , Continue to keep the temperature around 40 for 2h. The temperature of the Grignard reagent prepared above was cooled to about 0°C, and the mixture of 165g 2-methanesulfonylthiazole and 200mL THF was added dropwise. Warm to room temperature and stir for 1h. Then transfer to an ice-water bath, start to add 500mL 20% sulfuric acid solution dropwise, control the dropping rate, keep the internal temperature within 10, after the addition, raise to room temperature and stir for 1h; add dropwise 25% caustic soda solution to adjust the pH to 8 Separate the organic phase, extract the aqueous phase with 200 mL of THF once again, synthesize the organic phase, and concentrate to obtain 130 g of crude 2-propylthiazole, and rectify to obtain 106.5 g of pure 2-propylthiazole, with a yield of 84%.

References:

CN112898226, 2021, A Location in patent:Paragraph 0055-0058