Related Products of 103724-99-8, A common heterocyclic compound, 103724-99-8, name is 2-Bromo-5-chloro-1,3-dimethylbenzene, molecular formula is C8H8BrCl, 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.
To a 400 mL vessel equipped with a mechanical stirrer, thermometer, distillation head and dropping funnel, solid sodium hydroxide (10.9 g, 0.27 mol, microprills with 0.5 – 1 mm diameter) is charged under an inert atmosphere.1-Methyl-2-pyrrolidone (NMP, 137 g) is added to the vessel in one portion through the dropping funnel and the reaction mixture cooled to 10 – 15 C while stirring. A solution of malononitrile (NEC-CH2-CEN) (6.6 g, 0.10 mol) in NMP (8.9 g) is added through the dropping funnel over 10 – 15 minutes maintaining the temperature at 10 – 15 C. The reaction mixture is then heated to 100 C and a vacuum (30 mbar) applied, upon which solvent (40 g) is distilled off.2-Bromo-5-chloro-1 ,3-dimethyl-benzene (20 g, 0.089 mol) is then added through the dropping funnel over 5- 10 minutes, whilst maintaining the temperature at 100- 110 CC. A mixture containingpalladium (II) chloride (0.19 g, solution in conc. hydrochloric acid, assay 20% Pd, 0.36 mmol), triphenylphosphine (0.45 g, 1.6 mmol) and NMP (18 g) is then added through the dropping funnel over a 5 – 10 minute period. The temperature is allowed to rise to 124 C and the reaction mixture stirred at this temperature for 2 – 3 hours. Conversion is monitored by pulling samples and subsequent HPLC analysis.When conversion is complete, a vacuum (20-40 mbar) is applied and solvent (90 g) is distilled off. The resulting residue is cooled below 100 C and water (95 g) is added. After cooling to room temperature, the resulting mixture is filtered through hyflo (Hyflo SuperCel diatomaceous earth, ca. 10 g) and the filter cake washed with water (20 g). To the combined filtrates, hydrochloric acid (20.6 g, assay 32%, 0.18 mol) is added to adjust the pH from 13.3 to 2.7.The resulting mixture is extracted with tert-butyl-methyl ether (2 x 110 g). The organic phases are washed with water (2 x 50g) and the combined organic phases evaporated to dryness. The resulting solid residue is recrystallized from iso-propanol (63 g) and the resulting crystals filtered, washed with cold iso-propanol (5 g) and dried under vacuum to yield 2-(4-chloro-2,6-dimethyl-phenyl)propanedinitrile (melting point (m.p.) 145 – 147 C).
The synthetic route of 103724-99-8 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; SYNGENTA PARTICIPATIONS AG; ZELLER, Martin; FEDOU, Nicolas; (19 pag.)WO2018/15489; (2018); A1;,
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