Triphenylphosphine dibromide → 5-Bromo-3-(5-(3-methylthiophen-2-yl)-1,3,4-oxadiazol-2-yl)pyrazin-2-amine

HRID 78629

Reaction equation

HRID 78629 reaction equation
[NH2:1][C:2]1[C:3]([C:9]([NH:11][NH:12][C:13]([C:15]2[S:16][CH:17]=[CH:18][C:19]=2[CH3:20])=[O:14])=O)=[N:4][C:5]([Br:8])=[CH:6][N:7]=1.CCN(C(C)C)C(C)C.BrP(Br)(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1>C(#N)C>[Br:8][C:5]1[N:4]=[C:3]([C:9]2[O:14][C:13]([C:15]3[S:16][CH:17]=[CH:18][C:19]=3[CH3:20])=[N:12][N:11]=2)[C:2]([NH2:1])=[N:7][CH:6]=1

Participants

5

Reactant 3

HCID 70579Triphenylphosphine dibromideHCID 81531DiisopropylethylamineHCID 594723013-amino-6-bromo-N'-(3-methylthiophene-2-carbonyl)pyrazine-2-carbohydrazide

Product 1

HCID 594718295-Bromo-3-(5-(3-methylthiophen-2-yl)-1,3,4-oxadiazol-2-yl)pyrazin-2-amineYield 59.3%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

To a suspension of 3-amino-6-bromo-N′-(3-methylthiophene-2-carbonyl)pyrazine-2-carbohydrazide (7.85 g, 22.04 mmol) in anhydrous acetonitrile (117.8 mL) cooled in an ice bath was added DIPEA (8.546 g, 11.52 mL, 66.12 mmol) followed by dibromo(triphenyl)phosphorane (12.09 g, 28.65 mmol) portionwise. The resulting suspension was stirred at room temperature for 30 min and the precipitate isolated by filtration and washed with acetonitrile to give the product as a yellow solid (4.42 g, 52% yield); 1H NMR (400 MHz, DMSO) d 2.64 (s, 3H), 7.21 (d, 1H), 7.91 (3H, m) and 8.44 (s, 1H) ppm; MS (ES+) 340.04

Workup

  1. temperaturecooled in an ice bath
  2. customthe precipitate isolated by filtration
  3. washwashed with acetonitrile

Sources & evidence

ORD record
ord-b0660fef268f406389399a60a34a07e2
Source dataset
uspto-grants-2014_09
Patent number
US08841308B2

Linked notes

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