Triethylamine → tert-butyl 4-((5R,7R)-5-methyl-7-(4-nitrobenzoyloxy)-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylate

HRID 559428Notes

Reaction equation

HRID 559428 reaction equation
[N+:1]([C:4]1[CH:12]=[CH:11][C:7]([C:8](Cl)=[O:9])=[CH:6][CH:5]=1)([O-:3])=[O:2].[OH:13][C@H:14]1[C:18]2[N:19]=[CH:20][N:21]=[C:22]([N:23]3[CH2:28][CH2:27][N:26]([C:29]([O:31][C:32]([CH3:35])([CH3:34])[CH3:33])=[O:30])[CH2:25][CH2:24]3)[C:17]=2[C@H:16]([CH3:36])[CH2:15]1.C(N(CC)CC)C.C([O-])(O)=O.[Na+]>C(Cl)Cl>[CH3:36][C@H:16]1[C:17]2[C:22]([N:23]3[CH2:28][CH2:27][N:26]([C:29]([O:31][C:32]([CH3:35])([CH3:34])[CH3:33])=[O:30])[CH2:25][CH2:24]3)=[N:21][CH:20]=[N:19][C:18]=2[C@H:14]([O:13][C:8](=[O:9])[C:7]2[CH:6]=[CH:5][C:4]([N+:1]([O-:3])=[O:2])=[CH:12][CH:11]=2)[CH2:15]1

Participants

6

Reactant 4

HCID 8471TriethylamineHCID 85024-Nitrobenzoyl chlorideHCID 516892Sodium BicarbonateHCID 59580343tert-butyl 4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylate

Product 1

HCID 59580346tert-butyl 4-((5R,7R)-5-methyl-7-(4-nitrobenzoyloxy)-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylateYield 84.6%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

4-Nitrobenzoyl chloride (4.27 g, 23.0 mmol) was added to a 0° C. solution of tert-butyl 4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylate (7.0 g, 20.9 mmol) and triethylamine (4.38 ml, 31.4 mmol) in DCM (110 mL). The reaction mixture was stirred at room temperature overnight, after which saturated NaHCO3 was added. The mixture was stirred 10 minutes, and then extracted with DCM. The combined extracts were dried (Na2SO4), filtered, and concentrated. The crude was flashed on Biotage 65M (3:1 hexanes:ethyl acetate loaded crude, then 2:1 hexanes:ethyl acetate eluted tert-butyl 4-((5R,7R)-5-methyl-7-(4-nitrobenzoyloxy)-6,7-dihydro -5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylate and a few mixed fractions). Then tert-butyl 4-((5R,7S)-5-methyl-7-(4-nitrobenzoyloxy)-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylate was eluted using 1:2 hexanes:ethyl acetate. The fractions with product were concentrated by rotary evaporation to give tert-butyl 4-((5R,7R)-5-methyl-7-(4-nitrobenzoyloxy)-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylate (8.55 g, 84.5% yield) as a yellow foam. LC/MS (APCI+) m/z 484 [M+H]+. 1H NMR (CDCl3) shows single diastereomer). The fractions with other diastereomer were concentrated by rotary evaporation to give tert-butyl 4-((5R,7S)-5-methyl-7-(4-nitrobenzoyloxy)-6,7-dihydro-5H-cyclopenta[d]pyrimidin -4-yl)piperazine-1-carboxylate (0.356 g, 3.52% yield) as a brown foam. LC/MS (APCI+) m/z 484 [M+H]+.

Workup

  1. stirringThe mixture was stirred 10 minutes
  2. extractionextracted with DCM
  3. dry with materialThe combined extracts were dried (Na2SO4)
  4. filtrationfiltered
  5. concentrationconcentrated
  6. washethyl acetate loaded crude, then 2:1 hexanes:ethyl acetate eluted tert-butyl 4-((5R,7R)-5-methyl-7-(4-nitrobenzoyloxy)-6,7-dihydro -5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylate
  7. additiona few mixed fractions)
  8. washThen tert-butyl 4-((5R,7S)-5-methyl-7-(4-nitrobenzoyloxy)-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylate was eluted
  9. concentrationThe fractions with product were concentrated by rotary evaporation

Sources & evidence

ORD record
ord-7a7d2947409c4658a28df389bd856b6b
Source dataset
uspto-grants-2011_11
Patent number
US08063050B2

Reaction notes

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