Electric Literature of 1702-18-7 ,Some common heterocyclic compound, 1702-18-7, molecular formula is C6H2Cl2N2, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc., below Introduce a new synthetic route.
EXAMPLE 1 Preparation of 6-chloro-3-methylthio-2-pyridinecarbonitrile and 3-chloro-6-methylthio-2-pyridinecarbonitrile 69.2 Grams (g) of 3,6-dichloro-2-pyridinecarbonitrile was dissolved in 250 milliliters (ml) of THF and chilled to about 10 C. Methanethiol (19.2 g) was added and the whole mixture was cooled to about 5 C. While the temperature was maintained at about 0 to 5 C., 44.9 g of t-BuOK in 550 ml of THF was added slowly. After the addition of t-BuOK was complete, the reaction mixture was allowed to warm to room temperature, and was stirred for 3 hours and then poured onto ice, forming a precipitate which was collected by filtration. The precipitate was dissolved in CH2 Cl2, dried, concentrated and diluted with hexane to give 24.7 g of white crystalline material which was subsequently identified by NMR to be 6-chloro-3-methylthio-2-pyridinecarbonitrile. The filtrate from the above-described filtration was then concentrated leaving a solid which was recrystallized twice and filtered (retaining the filtrates after each recrystallization). The solid obtained was identified as 6-chloro-3-methylthio-2 -pyridinecarbonitrile (14.5 g). The retained filtrates were combined and concentrated to give 17.5 g of a mixture of 6-chloro-3-methylthio-2-pyridinecarbonitrile and 3-chloro-6-methylthio-2-pyridinecarbonitrile in a ratio of about 3:1, respectively. The isomers were then separated on a Waters Prep LC500 instrument using 15% ethyl acetate in hexane. The melting point of the 6-chloro-3-methylthio-2-pyridinecarbonitrile isomer was found to be 115-118 C., while 3-chloro-6-methylthio-2-pyridinecarbonitrile was found to have a melting point (m.p.) of 76-80 C.
In the field of chemistry, the synthetic routes of compounds are constantly being developed and updated. I will also mention this compound in other articles. 1702-18-7, 3,6-Dichloropicolinonitrile, other downstream synthetic routes, hurry up and to see.
Reference:
Patent; The Dow Chemical Company; US4558134; (1985); A;,
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem