2-Amino-5-fluoropyridine → (S)-3-(2-(tert-butyldiphenylsilyloxy)ethoxy)-N-(5-fluoropyridin-2-yl)-2-hydroxypropanamide

HRID 1098262Notes

Reaction equation

HRID 1098262 reaction equation
C[Al](C)C.[F:5][C:6]1[CH:7]=[CH:8][C:9]([NH2:12])=[N:10][CH:11]=1.[Si:13]([O:30][CH2:31][CH2:32][O:33][CH2:34][C@H:35]([OH:40])[C:36](OC)=[O:37])([C:26]([CH3:29])([CH3:28])[CH3:27])([C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1)[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1>C1(C)C=CC=CC=1>[Si:13]([O:30][CH2:31][CH2:32][O:33][CH2:34][C@H:35]([OH:40])[C:36]([NH:12][C:9]1[CH:8]=[CH:7][C:6]([F:5])=[CH:11][N:10]=1)=[O:37])([C:26]([CH3:29])([CH3:27])[CH3:28])([C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1)[C:14]1[CH:15]=[CH:16][CH:17]=[CH:18][CH:19]=1

Participants

5

Reactant 3

HCID 27377012-Amino-5-fluoropyridineHCID 16682925TrimethylaluminumHCID 59279512(S)-methyl 3-(2-(tert-butyldiphenylsilyloxy)ethoxy)-2-hydroxypropanoate

Product 1

HCID 57504704(S)-3-(2-(tert-butyldiphenylsilyloxy)ethoxy)-N-(5-fluoropyridin-2-yl)-2-hydroxypropanamideYield 55%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent2×

Conditions

Temperature
0 °C

Procedure

Trimethylaluminium (2M solution in toluene) (2.86 mL, 5.71 mmol) was added to 5-fluoropyridin-2-amine in toluene (8 mL) cooled to 0° C. under nitrogen. The resulting solution was stirred at 0° C. for 20 minutes. (S)-Methyl 3-(2-(tert-butyldiphenylsilyloxy)ethoxy)-2-hydroxypropanoate (Intermediate AB3) in toluene (8 mL) was added and the reaction was allowed to warm to room temperature and then heated at reflux for 24 hours. The reaction mixture was allowed to cool and concentrated in vacuo. The residue was neutralised with citric acid (1M, aq.) and then diluted with water (30 mL) and extracted with EtOAc (2×50 mL). The combined organics were dried (MgSO4) and evaporated. The crude product was purified by flash silica chromatography, eluting with 30 to 50% EtOAc in isohexane to afford the product (1.32 g, 55%). 1H NMR (400 MHz, CDCl3) δ 1.05 (s, 9H), 3.60-3.68 (m, 3H), 3.79-3.83 (m, 2H), 3.86 (d, 2H), 4.31-4.35 (m, 1H), 7.34-7.46 (m, 7H), 7.64-7.69 (m, 4H), 8.14 (d, 1H), 8.22-8.28 (m, 1H), 9.18 (s, 1H); m/z (ES+), (M+H)+=483.63; HPLC tR=3.08 min.

Workup

  1. temperatureto warm to room temperature
  2. temperatureheated
  3. temperatureat reflux for 24 hours
  4. temperatureto cool
  5. concentrationconcentrated in vacuo
  6. additiondiluted with water (30 mL)
  7. extractionextracted with EtOAc (2×50 mL)
  8. dry with materialThe combined organics were dried (MgSO4)
  9. customevaporated
  10. customThe crude product was purified by flash silica chromatography
  11. washeluting with 30 to 50% EtOAc in isohexane

Sources & evidence

ORD record
ord-af2d431f5b374d7ba674f2cc59974823
Source dataset
uspto-grants-2012_03
Patent number
US08143263B2

Reaction notes

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