Sodium triacetoxyborohydride → 6-[({1-[2-(5,7-Difluoro-2-oxoquinoxalin-1(2H)-yl)ethyl]piperidin-4-yl}amino)methyl]-2H-pyrido[3,2-b][1,4]oxazin-3(4H)-one

HRID 255357Notes

Reaction equation

HRID 255357 reaction equation
[NH2:1][CH:2]1[CH2:7][CH2:6][N:5]([CH2:8][CH2:9][N:10]2[C:19]3[C:14](=[C:15]([F:21])[CH:16]=[C:17]([F:20])[CH:18]=3)[N:13]=[CH:12][C:11]2=[O:22])[CH2:4][CH2:3]1.[O:23]=[C:24]1[CH2:29][O:28][C:27]2[CH:30]=[CH:31][C:32]([CH:34]=O)=[N:33][C:26]=2[NH:25]1.[BH-](OC(C)=O)(OC(C)=O)OC(C)=O.[Na+]>CO.C(OCC)(=O)C>[F:21][C:15]1[CH:16]=[C:17]([F:20])[CH:18]=[C:19]2[C:14]=1[N:13]=[CH:12][C:11](=[O:22])[N:10]2[CH2:9][CH2:8][N:5]1[CH2:4][CH2:3][CH:2]([NH:1][CH2:34][C:32]2[CH:31]=[CH:30][C:27]3[O:28][CH2:29][C:24](=[O:23])[NH:25][C:26]=3[N:33]=2)[CH2:7][CH2:6]1

Participants

6

Conditions

Temperature
0 °C

Procedure

To a solution of 1-[2-(4-aminopiperidin-1-yl)ethyl]-5,7-difluoroquinoxalin-2(1H)-one (Intermediate 192, 0.158 g) in methanol (10 mL) were added 3 Å molecular sieve power (0.15 g) and 3-oxo-3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazine-6-carbaldehyde (WO 2004/058144) (92 mg). After 2 hours at reflux, the reaction was cooled to 0° C. and NaBH(OAc)3 (0.19 g) was added. The reaction was allowed to warm to room temperature and was stirred overnight. It was diluted with ethyl acetate, filtered, washed with saturated solutions of Na2CO3 and brine, dried over sodium sulfate and concentrated. Chromatography on silica gel with 0-20% methanol in dichloromethane. Fractions containing product were collected, concentrated, dissolved in a minimum of CH2Cl2, precipitated with diethyl ether, and filtered to yield 104 mg of product.

Workup

  1. temperatureAfter 2 hours at reflux
  2. temperatureto warm to room temperature
  3. filtrationfiltered
  4. washwashed with saturated solutions of Na2CO3 and brine
  5. dry with materialdried over sodium sulfate
  6. concentrationconcentrated
  7. additionFractions containing product
  8. customwere collected
  9. concentrationconcentrated
  10. dissolutiondissolved in a minimum of CH2Cl2
  11. customprecipitated with diethyl ether
  12. filtrationfiltered

Sources & evidence

ORD record
ord-786d8a8802c7409bad8905dac2337b51
Source dataset
uspto-grants-2011_01
Patent number
US07875715B2

Reaction notes

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