2-Amino-5-methylpyridine → (S)-3-(2-(tert-butyldiphenylsilyloxy)ethoxy)-2-hydroxy-N-(5-methylpyridin-2-yl)propanamide

HRID 1098245Notes

Reaction equation

HRID 1098245 reaction equation
C[Al](C)C.[CH3:5][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]([CH3:5])=[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 153482-Amino-5-methylpyridineHCID 16682925TrimethylaluminumHCID 59279512(S)-methyl 3-(2-(tert-butyldiphenylsilyloxy)ethoxy)-2-hydroxypropanoate

Product 1

HCID 57504665(S)-3-(2-(tert-butyldiphenylsilyloxy)ethoxy)-2-hydroxy-N-(5-methylpyridin-2-yl)propanamideYield 76%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent2×

Conditions

Temperature
0 °C

Procedure

Trimethylaluminium (2M in toluene) (4.97 mL, 9.94 mmol) was added carefully to 5-methylpyridin-2-amine (1.075 g, 9.94 mmol) in toluene (20 mL) at 0° C. under nitrogen. The resulting solution was stirred at 0° C. for 15 minutes. (S)-methyl 3-(2-(tert-butyldiphenylsilyloxy)ethoxy)-2-hydroxypropanoate (Intermediate AB3) (2 g, 4.97 mmol) in toluene (4 mL) was added. The reaction was heated to 120° C. for 1 hour in the microwave reactor and cooled to RT. The reaction mixture was concentrated. The residue was neutralised with citric acid (1M, aq) and then diluted with water and extracted with EtOAc. The combined organics were dried (MgSO4) and evaporated. The crude product was purified by flash silica chromatography, elution gradient 0 to 50% EtOAc in isohexane to afford the product (1.800 g, 76%). 1H NMR (400 MHz, CDCl3) δ 1.04 (9H, s), 2.29 (3H, s), 3.65 (2H, t), 3.76-3.90 (5H, m), 4.31-4.37 (1H, m), 7.34-7.45 (6H, m), 7.48-7.54 (1H, m), 7.64-7.71 (4H, m), 8.07-8.13 (2H, m), 9.13 (1H, s); m/z (ES+) (M+H)+=479.60; HPLC tR=3.16 min.

Workup

  1. temperatureThe reaction was heated to 120° C. for 1 hour in the microwave reactor
  2. temperaturecooled to RT
  3. concentrationThe reaction mixture was concentrated
  4. additiondiluted with water
  5. extractionextracted with EtOAc
  6. dry with materialThe combined organics were dried (MgSO4)
  7. customevaporated
  8. customThe crude product was purified by flash silica chromatography, elution gradient 0 to 50% EtOAc in isohexane

Sources & evidence

ORD record
ord-a171c9239cbe42c181a8da2a5f1c0d90
Source dataset
uspto-grants-2012_03
Patent number
US08143263B2

Reaction notes

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