2-Bromo-6-methylpyridine

Light yellow liquid

under stirring conditions, the mass concentration in the reaction tank 46percent the hydrobromidum 756g, 2-amino-6-methyl pyridine 108g, heating to 60-62 °C and thermal insulation 1h, then cool to-5 - - 3°C, keep the range of the temperature is dropping 640g bromine BrExample 31; 2-bromopicoline (104); 2-amino-picoline (37.35 g, 0.346 mol) is added to a mechanically-stirred round-bottom flask in several stages, in a hydrobromic acid solution (48percent in water, 187 mL) at a temperature maintained between 20 and 30° C. After entire dissolution of the reagent, the reaction medium is cooled to 20° C. during the dropwise addition of dibromine (49 mL, 0.966 mol), for 30 min. The temperature of the solution is maintained at -20° C. for 90 minutes. In sodium nitrite solution (63.5 g, 6 mol) in water (100 mL) is added dropwise. The temperature of the solution is then brought to 15° C. in an hour and stirred for 45 minutes at that temperature. The medium is cooled to -20° C. and treated with a sodium solution (249 g, 400 mL HAn alkali trap, an equal pressure dropping funnel, a thermometer, and a mechanical stirrer were attached to a 1000 mL four-necked round bottom flask. (A) 2-amino-6-picoline (27.0 g 0.25 mol) and 48percent HBr (125 mL 2.31 mol) were placed in this reaction vessel. The reaction vessel was immersed in an ice bath and cooled to 0 ° C. Br2 (37.5 mL 0.72 mol) was transferred to an equal pressure dropping funnel, The temperature of the reaction solution was kept at 0 ° C. and slowly dropped into the reaction vessel over 90 minutes while vigorously stirring with a mechanical stirrer. NaNO 2 (42.5 g 0.62 mol) was weighed and dissolved in about 100 mL of distilled water. This was transferred to an equal pressure dropping funnel, While stirring vigorously with a stirrer, it dripped over about 2 hours. At this time, care was taken that the temperature of the reaction solution did not exceed 10 ° C. In order to complete the reaction, NaNO 2 (2.50 g 0.036 mol) was dissolved in about 10 mL of distilled water and added, It was confirmed that nitrogen gas was not generated from the reaction vessel. While cooling in an ice bath, NaOH (95.0 g, 2.4 mol) was dissolved in about 300 mL of distilled water, after cooling sufficiently, it was gradually added to the solution for neutralization. At this time, care was taken that the temperature of the reaction solution did not exceed 20 ° C. The reaction mixture was extracted with Et 2 O (200 mL × 4) and the organic layer was collected. Anhydrous Na 2 SO 4 was added and dried, Upon concentration, a brown oily substance was obtained. This oily substance was distilled under reduced pressure in a rectifying tube, fractionated at 55 ° C. to 60 ° C. at a reduced pressure degree of 7.00 mmHg, A yellow oily substance was obtained. This material was stored at -40 ° C. Yield: 72percent (32.0 g)1000 ml Four-neck reaction vessel was equipped with a mechanical stirrer, Alkaline trap, Two 200 ml isobaric dropping funnels were attached, (J) 2-amino-6-picoline (27.0 g 0.25 mol) was added, Was dissolved in 48percent HBr (125 ml 2.31 mol)The mixture was vigorously stirred with a mechanical stirrer.The reaction vessel was immersed in an ice bath containing saline, It was cooled to -10 ° C.The procedure up to neutralization below was done in an ice bath.Br2 (37.5 ml 0.72 mol) was transferred to an isobaric dropping funnel with vigorous stirring with a mechanical stirrer, And slowly added dropwise to the reaction vessel over about 2 hours while maintaining the temperature of the reaction solution at 0 ° C.The solution turned from light yellow to orange to brown.Weigh out NaNO 2 (42.5 g 0.615 mol)It was dissolved in about 100 ml distilled water.This was added dropwise from an isobaric dropping funnel over about 3 hours.At this time, Care was taken that the temperature of the reaction solution did not exceed 10 ° C.In order to complete the reaction, Further, NaNO 2 (2.50 g 0.036 mol) was dissolved in about 10 ml of distilled water and added, and it was confirmed that no bubbles were generated from the reaction solution.While keeping the solution at a low temperature in an ice bath, NaOH (95 g 2.35 mol) was dissolved in about 300 ml of distilled water, After cooling sufficiently, Was added to the solution little by little using an isobaric dropping funnel to neutralize.At this time, Care was taken that the temperature of the reaction solution did not exceed 20 ° C.When the pH became neutral, the color of the solution turned into fluorescent yellow.After checking that the pH reached around 8 with pH test paper, stop the addition, transfer the reaction solution to a separating funnel, extract with Et 2 O (300 ml × 5), collect the organic layer, dry with Na 2 SO 4, Upon concentration, a brown oily substance was obtained.This oily substance was subjected to distillation under reduced pressure (oil bath temperature 55 ° C.) using a distillation apparatus equipped with a rectifying tube to obtain 28.4 g of a transparent yellow oil substance.This material was degassed and purged with nitrogen and then stored at -40 ° C.Yield: 66percent

2-Bromo-6-methylpyridine is a halogenated pyridine derivative used is a building block in the preparation of nitrogen containing heterocyclic compounds.

Molecular Weight:172.02
XLogP3:1.8
Hydrogen Bond Acceptor Count:1
Exact Mass:170.96836
Monoisotopic Mass:170.96836
Topological Polar Surface Area:12.9
Heavy Atom Count:8
Complexity:74.9
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes