Water → Racemic (7S*,9aS*)-2-(Benzo[d]isoxazol-3-yl)perhydro-7-(hydroxymethyl)-1H-pyrido[1,2-a]pyrazine

HRID 466584Notes

Reaction equation

HRID 466584 reaction equation
[OH:1][CH2:2][CH:3]1[CH2:12][N:7]2[CH2:8][CH2:9][NH:10][CH2:11][CH:6]2[CH2:5][CH2:4]1.[N:13]12CCCN=[C:19]1[CH2:18][CH2:17][CH2:16][CH2:15][CH2:14]2.O.[C:25](=[O:28])([O-])[O-].[Na+].[Na+]>N1C=CC=CC=1.C(Cl)Cl>[O:28]1[C:25]2[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=2[C:14]([N:10]2[CH2:9][CH2:8][N:7]3[CH2:12][CH:3]([CH2:2][OH:1])[CH2:4][CH2:5][CH:6]3[CH2:11]2)=[N:13]1

Participants

7

Reactant 4

HCID 962WaterHCID 10340Sodium CarbonateHCID 811841,8-Diazabicyclo(5.4.0)undec-7-eneHCID 12985539(Octahydro-1H-pyrido[1,2-A]pyrazin-7-YL)methanol

Product 1

HCID 22491366Racemic (7S*,9aS*)-2-(Benzo[d]isoxazol-3-yl)perhydro-7-(hydroxymethyl)-1H-pyrido[1,2-a]pyrazineYield 51%

Reagents, catalysts & solvents 2

HCID 1049PyridineSolventHCID 6344DichloromethaneSolvent

Conditions

Temperature
35 °C

Procedure

A stirred solution of alcohol-amine title product of Example 3 (179.4 g, 1.05 mol), 3-chloro-1,2-benzo[d]-isoxazole (194.2 g, 1.26 mol), and 1,8-diazabicyclo-[5.4.0]undec-7ene (DBU, 197.9 g, 1.30 mol) in pyridine (400 ml) was heated at 100° C. for 18 hours. After cooling to 35° C., water (3 liters), methylene chloride (2.5 liters) and, finally, saturated aqueous sodium carbonate (2 liters) were added, and the resulting biphasic mixture was vigorously stirred for 3 hours. The tan solid precipitate which formed during the stirring period was filtered, and the filter cake was washed first with water and then with hexane (1 liter of each) prior to being dried in vacuo. Trituration of the entire sample (216 g) with isopropyl alcohol (630 ml) followed by filtration and in vacuo drying afforded present title compound (154.5 g, 51% yield) as a light tan powder, sufficiently pure for use in the next step without further purification. TLC Rf (methylene chloride/methanol=9:1 in volume; iodoplatinate spray): 0.50. 13CNMR (CDCl3) delta 164.0, 161.1, 129.5, 122.3, 122.1, 116.2, 110.5, 66.3, 60.3, 58.7, 54.3, 53.7, 48.3, 39.1, 29.0, 26.7.

Workup

  1. customThe tan solid precipitate which formed during the stirring period
  2. filtrationwas filtered
  3. washthe filter cake was washed first with water
  4. dry with materialwith hexane (1 liter of each) prior to being dried in vacuo
  5. filtrationTrituration of the entire sample (216 g) with isopropyl alcohol (630 ml) followed by filtration and in vacuo
  6. customdrying

Sources & evidence

ORD record
ord-42c8732a8779462f966c6b0d1918663e
Source dataset
uspto-grants-1992_10
Patent number
US05157034

Reaction notes

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