Ethanol → 3-Bromo-6-chloropyrazolo[1,5-a]pyrimidine

HRID 1842596Notes

Reaction equation

HRID 1842596 reaction equation
N#N.[NH2:3][C:4]1[C:8]([Br:9])=[CH:7][NH:6][N:5]=1.CN(/[CH:13]=[C:14](\[Cl:19])/[CH:15]=[N+](C)C)C.F[P-](F)(F)(F)(F)F.C(O)C>C(O)(=O)C>[Br:9][C:8]1[CH:7]=[N:6][N:5]2[CH:15]=[C:14]([Cl:19])[CH:13]=[N:3][C:4]=12

Participants

6

Reactant 4

HCID 702EthanolHCID 947NitrogenHCID 105908072-Chloro-1,3-bis(dimethylamino)trimethinium hexafluorophosphateHCID 178509245HCID 178509245, compound

Product 1

HCID 673469363-Bromo-6-chloropyrazolo[1,5-a]pyrimidineYield 80.8%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
70 °C

Procedure

A 5 L 4-neck round bottom flask equipped with mechanical stirrer, thermocouple, condenser and N2 bubbler was charged with 3-amino-4-bromopyrazole (40.0 g, 240 mmol), 2-Chloro-1,3-bis(dimethylamino)trimethinium hexafluorophosphate (77.0 g, 252 mmol) in acetic acid (390 ml)/ethanol (580 ml). The reaction mixture was heated to 70° C. for 8 hrs. Cool to 0° C. Filter off solids. Wash solids with 500 ml water then 500 ml MeOH and dried under high vac to afford the title compound (45.1 g, 194 mmol). LRMS (APCI) calc'd for (C6H3BrClN3) [M+H]+, 231.9; found 231.9. 1H NMR (CDCl3, 500 MHz) δ 8.74 (s, 1H), 8.52 (s, 1H), 8.14 (s, 1H).

Workup

  1. customA 5 L 4-neck round bottom flask equipped with mechanical stirrer
  2. temperatureCool to 0° C
  3. filtrationFilter off solids
  4. washWash solids with 500 ml water
  5. dry with material500 ml MeOH and dried under high vac

Sources & evidence

ORD record
ord-d2d13dc2b371450b93e0b6e18f022f55
Source dataset
uspto-grants-2015_02
Patent number
US08946237B2

Reaction notes

Loading…