Acetic Anhydride → 4-chloro-6,7-dihydro-5H-cyclopenta[d]pyrimidin-7-yl acetate

HRID 2200258Notes

Reaction equation

HRID 2200258 reaction equation
[Cl:1][C:2]1[N:7]=[CH:6][N+:5]([O-])=[C:4]2[CH2:9][CH2:10][CH2:11][C:3]=12.[C:12]([O:15]C(=O)C)(=[O:14])[CH3:13]>>[C:12]([O:15][CH:9]1[C:4]2[N:5]=[CH:6][N:7]=[C:2]([Cl:1])[C:3]=2[CH2:11][CH2:10]1)(=[O:14])[CH3:13]

Participants

3

Reactant 2

HCID 7918Acetic Anhydride2×HCID 142310914-chloro-6,7-dihydro-5H-cyclopenta[d]pyrimidine 1-oxide

Product 1

HCID 199689354-chloro-6,7-dihydro-5H-cyclopenta[d]pyrimidin-7-yl acetateYield 63%

Conditions

Temperature
110 °C

Procedure

The solution of 4-chloro-6,7-dihydro-5H-cyclopenta[d]pyrimidine 1-oxide (2.93 g, 17.2 mmol) in acetic anhydride (50 mL) was added dropwise to the acetic anhydride (50 mL) at 50° C. After addition, the mixture was stirred at 110° C. for 2 hour. After cooling, the solvent was removed and the residue was treated with toluene and hexanes (1:1, 200 mL). The mixture was stirred and then the solvent was removed. The residue was subject to chromatography on silica gel, eluted by hexanes/ethyl acetate (4:1-3:1) to afford the 4-chloro-6,7-dihydro-5H-cyclopenta[d]pyrimidin-7-yl acetate (2.3 g, 63%). 1H NMR (CDCl3, 400 MHz) δ 8.92 (s, 1H), 6.20-6.16 (m, 1H), 3.20-3.10 (m, 1H), 3.03-2.93 (m, 1H), 2.76-2.67 (m, 1H), 2.20-2.05 (m, 4H).

Workup

  1. additionAfter addition
  2. temperatureAfter cooling
  3. customthe solvent was removed
  4. additionthe residue was treated with toluene and hexanes (1:1, 200 mL)
  5. stirringThe mixture was stirred
  6. customthe solvent was removed
  7. washeluted by hexanes/ethyl acetate (4:1-3:1)

Sources & evidence

ORD record
ord-1dc2e4cc722f4233a22b3d4b4ab76afc
Source dataset
uspto-grants-2016_06
Patent number
US09359340B2

Reaction notes

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