Ammonium Chloride → (8R, 9R)-8-(t-Butydimethylsilyloxy)-6-methoxymethyl-2,3-dimethyl-9-phenyl-5,6,7,8,9,10-hexahydroimidazo[1,2-h][1,7]naphthyridin-7-one

HRID 2121485Notes

Reaction equation

HRID 2121485 reaction equation
[CH3:1][O:2][CH2:3][CH:4]1[CH2:9][N:8]2[C:10]([CH3:14])=[C:11]([CH3:13])[N:12]=[C:7]2[C:6](=O)[CH2:5]1.[NH2:16][C@H:17]([C:32]1[CH:37]=[CH:36][CH:35]=[CH:34][CH:33]=1)[C@@H:18]([O:24][Si:25]([C:28]([CH3:31])([CH3:30])[CH3:29])([CH3:27])[CH3:26])[C:19](OCC)=[O:20].C([N-]C(C)C)(C)C.[Li+].[Cl-].[NH4+]>C1(C)C=CC(S(O)(=O)=O)=CC=1.O1CCCC1.C1(C)C=CC=CC=1.O>[Si:25]([O:24][C@H:18]1[C:19](=[O:20])[C:5]2[CH:4]([CH2:3][O:2][CH3:1])[CH2:9][N:8]3[C:10]([CH3:14])=[C:11]([CH3:13])[N:12]=[C:7]3[C:6]=2[NH:16][C@@H:17]1[C:32]1[CH:33]=[CH:34][CH:35]=[CH:36][CH:37]=1)([C:28]([CH3:31])([CH3:30])[CH3:29])([CH3:27])[CH3:26]

Participants

9

Reactant 4

HCID 25517Ammonium ChlorideHCID 2724682Lithium diisopropylamideHCID 218739786-Methoxymethyl-2,3-dimethyl-5,6,7,8-tetrahydroimidazo[1,2-a]pyridin-8-oneHCID 69232107ethyl (2R,3R)-3-amino-2-(t-butyldimethylsilanyloxy)-3-phenylpropionate

Product 1

HCID 131724351(8R, 9R)-8-(t-Butydimethylsilyloxy)-6-methoxymethyl-2,3-dimethyl-9-phenyl-5,6,7,8,9,10-hexahydroimidazo[1,2-h][1,7]naphthyridin-7-oneYield 87.1%

Reagents, catalysts & solvents 4

HCID 6101p-Toluenesulfonic acidCatalystHCID 962WaterSolventHCID 1140TolueneSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-25 °C

Procedure

By using a water separator, a mixture of 2.66 g of 6-methoxymethyl-2,3-dimethyl-5,6,7,8-tetrahydroimidazo[1,2-a]pyridin-8-one, 4.27 g of ethyl (2R, 3R)-3-amino-2-(t-butyldimethylsilyloxy)-3-phenylpropionate, 70 mg of p-toluenesulfonic acid and 15 ml of toluene is boiled at reflux for 1.5 h. After cooling, 15 ml of tetrahydrofuran are added. With introduction of argon, the mixture is cooled to an internal temperature of −25° C. 15.4 ml of a commercial 2 molar solution of lithium diisopropylamide (Aldrich) are then added. The solution is stirred at −25° C. for 30 min. The solution is then allowed to warm to room temperature (30 min.) and poured into 30 ml of saturated aqueous ammonium chloride solution, the mixture is extracted three times with in each case 20 ml of ethyl acetate and the combined extracts are concentrated to dryness in vacuo. Purification on silica gel (mobile phase: methylene chloride/methanol=100/3) gives 5.2 g of the title compound as a yellowish amorphous solid. 1H-NMR(CDCl3, δ), 7.33-7.45 (m, 5H), 5.95 (d, 1H), 4.55-4.65 (dd, 1H), 4.2-4.4 (dd, 2H), 3.2-3.75 (m, 3H), 3.3 (s, 3H), 2.91-3.1 (q, 1H), 2.15 (s, 6H), 0.6 (d, 9H), 0.08 (d, 3H), −0.3 (d, 3H).

Workup

  1. temperatureat reflux for 1.5 h
  2. temperatureAfter cooling
  3. temperatureto warm to room temperature (30 min.)
  4. extractionthe mixture is extracted three times with in each case 20 ml of ethyl acetate
  5. concentrationthe combined extracts are concentrated to dryness in vacuo
  6. customPurification on silica gel (mobile phase: methylene chloride/methanol=100/3)

Sources & evidence

ORD record
ord-275316072a90456482196e31998af6f4
Source dataset
uspto-grants-2004_02
Patent number
US06696461B2

Reaction notes

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