Triethylamine → 3-(2-Methylsulfanyl-pyrimidin-4-yl)-6,7-dihydro-5h-pyrazolo[1,2-a]pyrazol-1-one

HRID 1455257Notes

Reaction equation

HRID 1455257 reaction equation
C(O[C:6](=[O:18])[CH2:7][C:8]([C:10]1[CH:15]=[CH:14][N:13]=[C:12]([S:16][CH3:17])[N:11]=1)=O)(C)(C)C.Cl.Cl.[NH:21]1[CH2:25][CH2:24][CH2:23][NH:22]1.C(N(CC)CC)C>C1(C)C=CC=CC=1>[CH3:17][S:16][C:12]1[N:11]=[C:10]([C:8]2[N:22]3[CH2:23][CH2:24][CH2:25][N:21]3[C:6](=[O:18])[CH:7]=2)[CH:15]=[CH:14][N:13]=1

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 12314782Pyrazolidine dihydrochlorideHCID 574380693-(2-Methylsulfanyl-pyrimidin-4-yl)-3-oxo-propionic acid tert-butyl ester

Product 1

HCID 574380973-(2-Methylsulfanyl-pyrimidin-4-yl)-6,7-dihydro-5h-pyrazolo[1,2-a]pyrazol-1-one

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

To a solution of 3-(2-methylsulfanyl-pyrimidin-4-yl)-3-oxo-propionic acid tert-butyl ester, 19, (6.8 g, 25.4 mmol), pyrazolidine-bishydrochloride (5.5 g, 38.1 mmol) and 4-angstrom molecular sieves (8.5 g) in toluene is added triethylamine (10.6 mL, 76.1 mmol). The reaction mixture is stirred for 4 hours at reflux. The solution is filtered through celite and washed with ether. The resulting yellow solid is purified over silica (10% MeOH/chloroform) to afford 5 g of the desired product as a yellow solid: 1H NMR (300 MHz, CDCl3) δ 8.72 (d, J=5.1 Hz, 1H), 7.62 (d, J=5.1 Hz, 1H), 6.08 (s, 1H), 4.26 (t, J=7.5 Hz, 2H), 3.80 (t, J=7.8 Hz, 2H), 2.62 (dddd, J=7.5, 7.5, 7.5, 7.5 Hz, 2H), 2.60 (s, 3H); ESI+ MS: m/z (rel intensity) 249.1 (70, M++H).

Workup

  1. temperatureat reflux
  2. filtrationThe solution is filtered through celite
  3. washwashed with ether
  4. customThe resulting yellow solid is purified over silica (10% MeOH/chloroform)

Sources & evidence

ORD record
ord-fd60735dc6ea4869bd1db1f857ed3a02
Source dataset
uspto-grants-2009_01
Patent number
US07482356B2

Reaction notes

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