Trifluoroacetic acid → 2-[trans-2-phenylcyclopropyl]tetrahydroimidazo[1,5-a]pyrazine-1,3(2H,5H)-dione

HRID 1260464Notes

Reaction equation

HRID 1260464 reaction equation
[O:1]=[C:2]1[CH:6]2[CH2:7][N:8](C(OC(C)(C)C)=O)[CH2:9][CH2:10][N:5]2[C:4](=[O:18])[N:3]1[C@@H:19]1[CH2:21][C@H:20]1[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1.C(O)(C(F)(F)F)=O>C(Cl)Cl>[C:22]1([C@@H:20]2[CH2:21][C@H:19]2[N:3]2[C:2](=[O:1])[CH:6]3[CH2:7][NH:8][CH2:9][CH2:10][N:5]3[C:4]2=[O:18])[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1

Participants

4

Reactant 2

HCID 6422Trifluoroacetic acidHCID 67300259tert-butyl 1,3-dioxo-2-[trans-2-phenylcyclopropyl]hexahydroimidazo[1,5-a]pyrazine-7(1H)-carboxylate

Product 1

HCID 673000522-[trans-2-phenylcyclopropyl]tetrahydroimidazo[1,5-a]pyrazine-1,3(2H,5H)-dioneYield 100%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A solution of A4 in DCM (0.5 M) was cooled to 0° C. (ice bath) and TFA (9 eq.) was added and the reaction was stirred at RT overnight. The solvent was removed under reduced pressure. The crude material was treated with Et2O (20 mL) and HCl (1N, 12 mL). The two layers were separated, and organic phase washed with water (2×15 mL). To the combined organic extracts was added solid K2CO3 in small portion until pH 9-10. The mixture was extracted with DCM and combined extracts were dried and evaporated under reduced pressure to yield (100%) the desired compound that was used crude in the next step. 1H NMR (400 MHz, DMSO-d6, 300K) δ 7.29-7.20 (5H, m), 3.90 (1H, m), 3.78 (1H, m), 3.15 (1H, m), 2.85 (3H, m), 2.65 (1H, m), 2.50-2.30 (3H, m), 1.5 (1H, m), 1.35 (1H, m). MS (ES+) C15H17N3O2 requires 271, found: 272 (M+H)+.

Workup

  1. additionwas added
  2. customThe solvent was removed under reduced pressure
  3. additionThe crude material was treated with Et2O (20 mL) and HCl (1N, 12 mL)
  4. customThe two layers were separated
  5. washorganic phase washed with water (2×15 mL)
  6. additionTo the combined organic extracts was added solid K2CO3 in small portion until pH 9-10
  7. extractionThe mixture was extracted with DCM
  8. customwere dried
  9. customevaporated under reduced pressure

Sources & evidence

ORD record
ord-e11b39298ad84133a1222b66c2214c0f
Source dataset
uspto-grants-2013_06
Patent number
US08470823B2

Reaction notes

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