ChemicalBook CAS DataBase List 2,5-Dibromopyrazine

2,5-Dibromopyrazine synthesis

3synthesis methods

Product Name:2,5-Dibromopyrazine
CAS Number:23229-26-7
Molecular formula:C4H2Br2N2
Molecular Weight:237.88

5-bromopyrazin-2-amine (3 g, 17.241 mmol) and bromine (8.2 g, 51.729 mmol) were added to aq. HBr solution at -15° C. Aq. solution of sodium nitrite (2.97 g, 43.0103 mmol) was then added to the mixture over a period of 1 h at -10° C. keeping the internal temperature below 5° C. during addition and stirred for 1 h at 0° C. Progress of reaction was monitored by TLC. After reaction completion reaction mass neutralised with 40percent NaOH solution and extracted with diethyl ether. The organic layer was dried over sodium sulphate and concentrated under reduced pressure (below 30° C.) to yield 2,5-Dibromopyrazine (1 g, 24.4percent) as brown oil.

59489-71-3 Synthesis

59489-71-3
386 suppliers
$5.00/1g

23229-26-7
234 suppliers
$10.00/1g

Yield:23229-26-7 24.4%

Reaction Conditions:

with hydrogen bromide;bromine;sodium nitrite in water at -15 - 0; for 2 h;

Steps:

32.2 Step 2: Synthesis of 2,5-dibromopyrazine
Step 2:
Synthesis of 2,5-dibromopyrazine
5-bromopyrazin-2-amine (3 g, 17.241 mmol) and bromine (8.2 g, 51.729 mmol) were added to aq. HBr solution at -15° C. Aq. solution of sodium nitrite (2.97 g, 43.0103 mmol) was then added to the mixture over a period of 1 h at -10° C. keeping the internal temperature below 5° C. during addition and stirred for 1 h at 0° C.
Progress of reaction was monitored by TLC.
After reaction completion reaction mass neutralised with 40% NaOH solution and extracted with diethyl ether.
The organic layer was dried over sodium sulphate and concentrated under reduced pressure (below 30° C.) to yield 2,5-dibromopyrazine (1 g, 24.4%) as brown oil.
MS: 238.8[M⁺+1]

References:

Mankind Pharma Ltd.;Patil, Rakesh Ishwar;Verma, Jeevan;Shah, Dharmesh;Ali, Sazid;Bapuram, Srinivasa Reddy;Rai, Santosh Kumar;Kumar, Anil US2017/291910, 2017, A1 Location in patent:Paragraph 0592-0594

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290-37-9 Synthesis

290-37-9
304 suppliers
$5.00/5g

23229-26-7
234 suppliers
$10.00/1g

References

56423-63-3 Synthesis

56423-63-3
158 suppliers
$9.00/100mg

23229-26-7
234 suppliers
$10.00/1g

References

2,5-Dibromopyrazine Related Search:

Glipizide 2,5-Dibromopyridine 2,5-Difluorobenzoic acid 2,5-Dimethylfuran 2-Amino-3,5-dibromopyrazine 2,6-Dibromopyrazine 2,5-DIBROMO-3-METHOXYPYRAZINE 3,6-dibromopyrazin-2-amine 2,3-DIBROMOPYRAZINE methyl 3,6-dibromopyrazine-2-carboxylate