Pyridine → HCID 15255360, compound

HRID 1460123Notes

Reaction equation

HRID 1460123 reaction equation
Br[C:2]1[CH:3]=[N:4][CH:5]=[CH:6][CH:7]=1.[Si:8]([O:15][C:16]1[CH:17]=[C:18]([CH:21]=[CH:22][CH:23]=1)[CH:19]=[O:20])([C:11]([CH3:14])([CH3:13])[CH3:12])([CH3:10])[CH3:9].C([Li])CCC.N1C=CC=CC=1>C(OCC)C.C(=O)=O.CC(C)=O>[Si:8]([O:15][C:16]1[CH:17]=[C:18]([CH:19]([C:2]2[CH:3]=[N:4][CH:5]=[CH:6][CH:7]=2)[OH:20])[CH:21]=[CH:22][CH:23]=1)([C:11]([CH3:14])([CH3:13])[CH3:12])([CH3:10])[CH3:9]

Participants

7

Reactant 4

HCID 1049PyridineHCID 122863-BromopyridineHCID 112071113-(t-Butyldimethylsilyloxy)benzaldehydeHCID 178418339Butyllithium

Product 1

HCID 15255360HCID 15255360, compoundYield 98.5%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 18522661Acetone cardiceSolvent

Procedure

3-Bromopyridine (50.0 g, 0.316 mol) and 3-(tert-butyldimethylsilyloxy)benzaldehyde (74.8 g, 0.316 mol, Example 54, infra) were each dissolved in 500 mL anhydrous diethyl ether under nitrogen and chilled to -78° C. in dry ice/acetone baths. n-Butyllithium (198 mL, 0.316 mol, 1.6M in hexanes) was added dropwise to the chilled pyridine solution, at a rate that maintained the temperature below -70° C. After the addition was complete, the reaction was stirred for 10 minutes. The aldehyde solution was then added to the reaction mixture via cannula, while maintaining the temperature below -70° C. The reaction was stirred at -78° C. for 45 minutes and quenched with aqueous saturated ammonium chloride. The reaction mixture was allowed to warm to room temperature and was washed with water and brine. The ether extracts were dried over sodium sulfate and the solvent removed to give 98.2 g of crude (3-(tert-butyldimethylsilyloxy)phenyl)(3-pyridyl)methanol. The crude alcohol was dissolved in 300 mL of dichloromethane and chilled in an ice bath. Thionyl chloride (34 mL, 0.47 mol) was dissolved in 30 mL of dichloromethane and added dropwise to the chilled alcohol solution. After stirring for 3 hours, the solvent was removed to give the hydrochloride salt of (tert-butyldimethylsilyl) (3-(α-chloro-3-pyridylmethyl)phenyl) ether as a brown solid. The crude alkylchloride (approx. 0.311 mol) was combined with 120 g (0.78 mol) of N-allyl-trans-2,5-dimethylpiperazine (Example 42, infra) in 100 mL of acetonitrile and heated at reflux overnight. After the reaction was cooled to room temperature, 62 g (approx. 0.43 mol) of tetraethylammonium fluoride hydrate was added, and the reaction was stirred for 1 hour. The solvent was removed and the product was purified by chromatography on silica gel with 0-20% ethanol in dichloromethane. The first isomer to elute was obtained as 14.7 g of a dark oil which crystallized from 100 mL of acetonitrile upon standing at room temperature to give 3.0 g of (±)-3-((R*)-((2R*,5S*)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-pyridylmethyl)phenol, mp 115°-118° C. Calc for C21H28 N3O: C, 74.52; H, 8.34; N, 12.41. Found: C, 74.78; H, 8.11; N, 12.47. NMR (200 MHz, DMSO-d6): δ 0.95 (d, J=6 Hz, 3H); 1.09 (d, J=6 Hz, 3H); 1.84 (dd, J1 =7.6 Hz, J2 =11.7 Hz, 1H); 2.10 (dd, J1 =6,8 Hz, J2 =10.8 Hz, 1H); 2.5-2.8 (m, 4H); 2.86 (dd, J1 =7.2 Hz, J2 =14.0 Hz, 1H); 3.18 (dd, J1 =5.3 Hz, J2 =14 Hz, 1H); 5.05 (s, 1H); 5.8 (m, 1H); 6.7 (m, 3H); 7.16 (t, J=7.6 Hz, 1H); 7.34 (dd, J1 =4.9 Hz, J2 =8.0 Hz, 1H); 7.75 (d, J=7.9 Hz, 1H); 8.43 (d, J=4.6 Hz, 1H); 8.57 (s,1H); 9.41 (s,1H).

Workup

  1. temperaturethat maintained the temperature below -70° C
  2. additionAfter the addition
  3. temperaturewhile maintaining the temperature below -70° C
  4. stirringThe reaction was stirred at -78° C. for 45 minutes
  5. customquenched with aqueous saturated ammonium chloride
  6. washwas washed with water and brine
  7. dry with materialThe ether extracts were dried over sodium sulfate
  8. customthe solvent removed

Sources & evidence

ORD record
ord-2fa4dcb1959343c1a50acab70b9ca0d9
Source dataset
uspto-grants-1998_12
Patent number
US05854249

Reaction notes

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