624-28-2, In the chemical reaction process,reaction time,type of solvent,can easily affect the result of the reaction, thereby determining the yield and properties of the reaction product.An updated downstream synthesis route of 624-28-2 as follows.
A 12L three-necked round-bottomed flask equipped with a mechanical stirrer and a condenser, connected on top with a nitrogen [BUBBLER] and a thermometer, was charged with 2,5-dibromopyridine (442 g, 1. [87MOLES),] hydrazine hydrate (55% wt., 1057 ml, [18.] 7 moles), poly (ethylene glycol) (average Mn about 300,1. 87 L), 2-butanol (373 [ML)] and water (1.87 L). The mixture was heated at reflux for 29 hours. The heating source was removed and the mixture was stirred for an additional 20 hours. To the resulting slurry, cold water [(2.] 2L) was added. The slurry was stirred for an additional [30] minutes and filtered. The cake was washed with cold water (3 x [200] [ML)] and dried in a vacuum-oven [(40C)] for 48 hours. The title compound was obtained as off-white flakes (305 g, yield 87%). GCMS (m/z): 187 (M+). [H’NMR] (400 MHz, [CDCI3)] : 8 8.14 (d, J=2.0 Hz, 1H), 7.55 (dd, J=8.7/2. 0 Hz, 1 H), 6.66 (d, J=8.7Hz, [1 H),] 5.89 (brs, 1 H), 3.65 (brs, 2H).
The chemical industry reduces the impact on the environment during synthesis 624-28-2, I believe this compound will play a more active role in future production and life.
Reference:
Patent; PFIZER PRODUCTS INC.; WO2004/20438; (2004); A2;,
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem