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

HRID 78615

Reaction equation

HRID 78615 reaction equation
[NH2:1][C:2]1[C:3]([C:9]([OH:11])=O)=[N:4][C:5]([Br:8])=[CH:6][N:7]=1.[S:12]1[CH:16]=[CH:15][CH:14]=[C:13]1[C:17]([NH:19][NH2:20])=O.BrP(Br)(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.CCN(C(C)C)C(C)C>C(#N)C>[Br:8][C:5]1[N:4]=[C:3]([C:9]2[O:11][C:17]([C:13]3[S:12][CH:16]=[CH:15][CH:14]=3)=[N:19][N:20]=2)[C:2]([NH2:1])=[N:7][CH:6]=1

Participants

6

Reactant 4

HCID 70579Triphenylphosphine dibromideHCID 73098Thiophene-2-carbohydrazideHCID 81531Diisopropylethylamine3×HCID 185216003-Amino-6-bromopyrazine-2-carboxylic acid

Product 1

HCID 594719085-Bromo-3-(5-(thiophen-2-yl)-1,3,4-oxadiazol-2-yl)pyrazin-2-amineYield 58.3%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent2×

Procedure

3-amino-6-bromo-pyrazine-2-carboxylic acid (3.2 g, 14.68 mmol) and thiophene-2-carbohydrazide (2.152 g, 14.68 mmol) were suspended in acetonitrile (48.00 mL) at room temperature and dibromo(triphenyl)phosphorane (24.79 g, 58.72 mmol) was added, followed byadditional acetonitrile (16.00 mL). The reaction mixture turned bright yellow in colour and was stirred at room temperature for 1 h. After this time, the reaction mixture cooled in an icebath and DIPEA (7.209 g, 9.716 mL, 55.78 mmol) was added dropwise. The reaction mixture was stirred in the ice bath for 1 h and then additional DIPEA (2.277 g, 3.069 mL, 17.62 mmol) added and the reaction mixture stirred for left for 30 mins and further DIPEA (1.897 g, 2.557 mL, 14.68 mmol) added. The reaction mixture was stirred for 1 h and then filtered. The solid was washed with ether, isolated and then triturated with acetonitrile and washed with ether to give the product as a yellow solid (2.776 g, 57% yield); 1H NMR (400.0 MHz, DMSO) 7.35 (s, 1H), 7.80 (br s, 2H), 7.98 (m, 1H), 8.04 (m, 1H) and 8.45 (s, 1H); MS (ES+) 326.04

Workup

  1. additionwas added dropwise
  2. stirringthe reaction mixture stirred
  3. waitfor left for 30 mins
  4. stirringThe reaction mixture was stirred for 1 h
  5. filtrationfiltered
  6. washThe solid was washed with ether
  7. customisolated
  8. customtriturated with acetonitrile
  9. washwashed with ether

Sources & evidence

ORD record
ord-539a504bdf254e19943bf081b9102183
Source dataset
uspto-grants-2014_09
Patent number
US08841308B2

Linked notes

Loading…