Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps, and cheap raw materials. 38573-88-5, name is 1-Bromo-2,3-difluorobenzene, A new synthetic method of this compound is introduced below., COA of Formula: C6H3BrF2
MTBE (60 mL) was charged to a 3-neck round bottom flask followed by bromo-2,3- difluoro-benzene (12 mL, 107 mmol). The solution was cooled in ice/salt bath. When the internal temperature reached 40C addition of i-PrMgClLiCl solution in THF (1.3M, 90.7 mL, 118 mmol) was started. The higher internal temperature during addition was 2 ¡ãC(bath temperature was -8¡ãC to -5¡ãC); addition time 17 mm. After addition was complete the reaction mixture was stirred at -5¡ãC to 0¡ãC for one hour. Tert-Butyl 3-oxopyrrolidine-1 – carboxylate (21 .8 g, 118 mmol) solution in MTBE (200 mL) was added to the reaction mixture at -4¡ãC to -2¡ãC during 15 mm. under vigorous stirring. The reaction mixture was stirred at -2¡ãC to 0¡ãC for 3 hours and then quenched by addition of 20percent aqueousammonium chloride solution (260 mL). The internal temperature rose from 0 ¡ãC to 15 ¡ãC during addition. The cooling bath was removed and the mixture was stirred at room temperature for 1 hour. Layers were separated and the aqueous phase was re-extracted with MTBE (120 mL). Combined organic extracts were washed with brine (160 mL) and water (2 x 120 mL). Organic layer was concentrated to approx. 120 mL volume. MTBE(120 mL) was added and solvent evaporated to 120 mL volume left. 120 mL of MTBE was added again and evaporated till 120 mL volume left. Cyclohexane (120 mL) was added and mixture concentrated until remaining volume was 120 mL. Co-evaporation with cyclohexane was repeated two times using 120 mL of cyclohexane each time. Final solution (160 mL) was stirred at room temperature. After 30 minutes, solution becamecloudy and crystallization started. The slurry was stirred for 2 hours at room temperature and then for 2 hours at 5 to 10 ¡ãC. Precipitate was filtered off, washed on the filter with cyclohexane (2 x 30 mL). Since the freezing of cyclohexane causes suction to dry on the filter, wet material was dried under vacuum at 40 00. There was obtained 22 g (69percent) of the Compound of Formula (VIa) as a solid and the purity thereof was 98 areapercent as determined by HPLC (UV detection at 220 nm). Content of the impurity Compound of Formula (VIII) as described herein was 1 .2percent as determined by HPLC (UV detection at220 nm).
The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.
Reference:
Patent; INTEGRATIVE RESEARCH LABORATORIES SWEDEN AB; SONESSON, Clas; BUKSA, Maija; REINE, Inese; (76 pag.)WO2018/211080; (2018); A1;,
Bromide – Wikipedia,
bromide – Wiktionary