preparation method of 5-isopropylpyridin-2-amine_industrial additives

background and overview of the preparation method of 5-isopropylpyridin-2-amine

5-isopropylpyridin-2-amine can be used as a pharmaceutical synthesis intermediate. if 5-isopropylpyridin-2-amine is inhaled, move the patient to fresh air; if there is skin contact, take off contaminated clothing, rinse the skin thoroughly with soap and water, and seek medical attention if you feel unwell; if in case of eye contact, separate eyelids, rinse with running water or saline, and seek medical attention immediately; if ingested, rinse mouth immediately, do not induce vomiting, and seek medical attention immediately.

preparation method of 5-isopropylpyridin-2-amine

the preparation of 5-isopropylpyridin-2-amine is divided into the following two steps:

step 1: 5-(prop-1-en-2-yl)pyridin-2-amine. to a stirred and degassed solution of 5-bromopyridin-2-amine (3.5 g, 20.34 mmol) in aqueous 1,4-dioxane (1:1, 40 ml) was added potassium phosphate (12.94 g, 61.04 mmol), and continue degassing for 10 minutes. then, 4,4,5,5-tetramethyl-2-(prop-1-en-2-yl)-1,3,2-dioxaborolane (5.21g, 30.51mmol), then [1,2-bis(diphenylphosphino))ferrocene] was added with palladium(ii) dichloride (1.47 mg, 2.014 mmol), degassed under stirring for 10 minutes and heated to 100°c for 2 hours. . the reaction mixture was cooled to room temperature and filtered through a pad of celite. add cold water to the filtrate and extract with ethyl acetate (3 × 200 ml). the organic layer was washed with water (2 × 100 ml), brine (100 ml), dried over sodium sulfate and concentrated. the resulting residue was purified by column chromatography on silica gel (100-200 mesh), eluting with 40% ethyl acetate in petroleum ether, to give 5-(prop-1-en-2-yl)pyridin-2-amine (2.5 g, 18.65 mmol, yield 91%) as a brown solid. ms (esi) m/z135.18[m+1]+.

step 2: 5-isopropylpyridin-2-amine. to a slurry of 20% palladium hydroxide (1 g) in ethyl acetate (50 ml) was added 5-(prop-1-en-2-yl)pyridin-2-amine (2.5 g, 18.65 mmol) and stirred at room temperature. hydrogen balloon (1 arm) for 2 hours. the reaction mixture was filtered through a pad of celite, dried over sodium sulfate and concentrated to give 5-isopropylpyridin-2-amine (2 g, 14.70 mmol of trifluoromethoxypyridine, 79% yield) as a brown liquid. ms (esi) m/z137.15[m+1]+.

main reference materials for the preparation method of 5-isopropylpyridin-2-amine

[1] wo2016007848 antiproliferative compounds asodium carbonatend methods of use thereof