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CLEAR COLOURLESS LIQUID

Cyclobutyl bromide is a cyclopentyl compound that has an hydroxyl group. It is a potent inhibitor of the CB2 receptor, which is primarily expressed on cells of the immune system. Cyclobutyl bromide has been shown to inhibit the uptake of uv light and also has anti-inflammatory properties. Studies have confirmed that this drug inhibits the production of cytokines and chemokines in chronic bronchitis patients, as well as other inflammatory diseases such as rheumatoid arthritis.

The general procedure for the synthesis of cyclobutyl bromide and bromomethyl cyclopropane using hydroxymethyl cyclopropane as a starting material was as follows: first, a stirrer and thermometer were assembled on a 30 mL three-necked flask. 0.36 g (5.0 mmol) of hydroxymethylcyclopropane and 5 mL of chloroform were added to the flask, and the mixture was subsequently cooled to 10 °C with stirring. Then, 2.77 g (6.5 mmol) of a 19% hydrogen bromide/1,4-dioxane solution was slowly added dropwise. After the dropwise addition, the reaction mixture was heated to room temperature and stirring was continued for 2 hours. Upon completion of the reaction, the reaction mixture was analyzed by gas chromatography (GC) to afford cyclobutyl bromide and bromomethyl cyclopropane in 74% overall yield. In addition, the reaction produced bromocyclobutane (9% yield) and 4-bromo-1-butene (2% yield) as isomers.

[1] Patent: JP2017/14124, 2017, A. Location in patent: Paragraph 0033
[2] European Journal of Medicinal Chemistry, 1980, vol. 15, # 6, p. 571 - 573
[3] Patent: JP5979791, 2016, B2. Location in patent: Paragraph 0036-0038; 0042-0052