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

HRID 1746981Notes

Reaction equation

HRID 1746981 reaction equation
O[Li].O.C([O:7][CH:8]1[C:12]2[N:13]=[CH:14][N:15]=[C:16]([N:17]3[CH2:22][CH2:21][N:20]([C:23]([O:25][C:26]([CH3:29])([CH3:28])[CH3:27])=[O:24])[CH2:19][CH2:18]3)[C:11]=2[C@H:10]([CH3:30])[CH2:9]1)(=O)C.C1COCC1.[NH4+].[Cl-]>O>[OH:7][CH:8]1[C:12]2[N:13]=[CH:14][N:15]=[C:16]([N:17]3[CH2:22][CH2:21][N:20]([C:23]([O:25][C:26]([CH3:29])([CH3:28])[CH3:27])=[O:24])[CH2:19][CH2:18]3)[C:11]=2[C@H:10]([CH3:30])[CH2:9]1

Participants

6

Reactant 4

HCID 8028TetrahydrofuranHCID 25517Ammonium ChlorideHCID 168937Lithium hydroxide, monohydrateHCID 59580360(R)-tert-butyl 4-(7-acetoxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylate

Product 1

HCID 59580348(R)-tert-butyl 4-(7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylateYield 56.4%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

LiOH—H2O (6.577 g, 156.7 mmol) was added to a 0° C. solution of (5R)-tert-butyl 4-(7-acetoxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylate (23.6 g, 62.69 mmol) in 2:1 THF:H2O (320 mL). The reaction mixture was stirred for 10 minutes, and then warmed to room temperature. LC/MS looked the same at 3 hours and 4.5 hours. The reaction mixture was cooled to 0° C., and then saturated NH4Cl was added to the mixture. The mixture was stirred for 5 minutes, and most of the THF was removed by rotary evaporation. The mixture was extracted with EtOAc (3×250 mL), and the combined extracts were dried (Na2SO4), filtered, and concentrated. The crude was flashed on Biotage 65M: 4:1 DCM:ethyl acetate, then gradient to 1:1 to 1:4 DCM:ethyl acetate. Once the product was eluting, then ethyl acetate was flushed through the column. Then 30:1 DCM:MeOH eluted the rest of the product (8.83 g). The mixed fractions were re-flashed with Biotage 40M using the same conditions to give another 2.99 g which gave a combined yield of (5R)-tert-butyl 4-(7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylate (11.82 g, 56.38% yield) as a brown foam. LC/MS (APCI+) m/z 335.1 [M+H]+.

Workup

  1. customsame at 3 hours
  2. custom4.5 hours
  3. temperatureThe reaction mixture was cooled to 0° C.
  4. stirringThe mixture was stirred for 5 minutes
  5. custommost of the THF was removed by rotary evaporation
  6. extractionThe mixture was extracted with EtOAc (3×250 mL)
  7. dry with materialthe combined extracts were dried (Na2SO4)
  8. filtrationfiltered
  9. concentrationconcentrated
  10. washOnce the product was eluting
  11. customethyl acetate was flushed through the column
  12. washThen 30:1 DCM:MeOH eluted the rest of the product (8.83 g)
  13. customto give another 2.99 g which

Sources & evidence

ORD record
ord-726570aafce34eef843da9410f8e6209
Source dataset
uspto-grants-2015_10
Patent number
US09150548B2

Reaction notes

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