Formaldehyde → phenylmethyl 4-methyloctahydro-1(2H)-quinoxalinecarboxylate

HRID 1366659Notes

Reaction equation

HRID 1366659 reaction equation
[N:1]1([C:11]([O:13][CH2:14][C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)=[O:12])[CH:10]2[CH:5]([CH2:6][CH2:7][CH2:8][CH2:9]2)[NH:4][CH2:3][CH2:2]1.C=O.[C:23](O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+]>ClCCl>[CH3:23][N:4]1[CH:5]2[CH:10]([CH2:9][CH2:8][CH2:7][CH2:6]2)[N:1]([C:11]([O:13][CH2:14][C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)=[O:12])[CH2:2][CH2:3]1

Participants

5

Reactant 3

HCID 712FormaldehydeHCID 5049666Sodium triacetoxyborohydrideHCID 45358656Benzyl octahydroquinoxaline-1(2H)-carboxylate

Product 1

HCID 66936560phenylmethyl 4-methyloctahydro-1(2H)-quinoxalinecarboxylateYield 93.8%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a solution of phenylmethyl octahydro-1(2H)-quinoxalinecarboxylate (enantiomeric mixture) (2.32 g, 8.5 mmol) in dichloromethane (80 mL) at 0° C. was added formaldehyde (0.76 mL, 37% water solution, 10.2 mmol) followed by sodium triacetoxyborohydride (2.7 g, 12.75 mmol). The reaction mixture was allowed to warm to room temperature and stirred for 1 h before being diluted with dichloromethane and washed with 1N NaOH solution. The organics were washed with brine, dried (Na2SO4) and evaporated to yield 2.3 g of phenylmethyl 4-methyloctahydro-1(2H)-quinoxalinecarboxylate (enantiomeric mixture, cis) (2.3 g), which was separated by chiral LC to afford phenylmethyl (4aS,8aR)-4-methyloctahydro-1(2H)-quinoxalinecarboxylate, and phenylmethyl (4aR,8aS)-4-methyloctahydro-1(2H)-quinoxalinecarboxylate. Absolute configuration was assigned using Ab Initio vibrational circular dichroism. LCMS: (M+H)+: 289.2.

Workup

  1. washwashed with 1N NaOH solution
  2. washThe organics were washed with brine
  3. dry with materialdried (Na2SO4)
  4. customevaporated

Sources & evidence

ORD record
ord-2b2a3a6c04384a99b1f0e2c52c77d3d6
Source dataset
uspto-grants-2011_02
Patent number
US07893056B2

Reaction notes

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