Diethyl squarate → HCID 10813912, compound

HRID 1604012Notes

Reaction equation

HRID 1604012 reaction equation
C(O[C:4]1[C:5](=[O:12])[C:6](=[O:11])[C:7]=1[O:8][CH2:9][CH3:10])C.[CH2:13]([O:15][P:16]([CH2:21][CH2:22][NH:23][CH2:24][CH2:25][CH2:26][NH:27][C:28]([O:30][C:31]([CH3:34])([CH3:33])[CH3:32])=[O:29])(=[O:20])[O:17][CH2:18][CH3:19])[CH3:14]>C(O)C>[C:31]([O:30][C:28](=[O:29])[NH:27][CH2:26][CH2:25][CH2:24][N:23]([CH2:22][CH2:21][P:16]([O:15][CH2:13][CH3:14])([O:17][CH2:18][CH3:19])=[O:20])[C:4]1[C:5](=[O:12])[C:6](=[O:11])[C:7]=1[O:8][CH2:9][CH3:10])([CH3:34])([CH3:32])[CH3:33]

Participants

4

Reactant 2

HCID 123228Diethyl squarateHCID 10903865HCID 10903865, compound

Product 1

HCID 10813912HCID 10813912, compound

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Procedure

To a solution of 3,4-diethoxy-3-cyclobutene-1,2-dione (45 g, 0.265 mole; Aldrich 31,077-8) in absolute ethanol (1.2 L) under nitrogen was added dropwise a solution of N-[3-(t-butyloxycarbonylamino)propyl]-2-aminoethylphosphonic acid diethyl ester (80 g, 0.24 mole) in absolute ethanol (600 mL) and the reaction mixture was stirred at ambient temperature 15 hr. The reaction mixture was concentrated in vacuo and the residue was put on a pad of silica gel (6"×4") and eluted first with a mixture of methylene chloride/hexane 1:1 to remove excessive 3,4-diethoxy-3-cyclobutene-1,2-dione and finally with 10% methanol/methylene chloride to yield the title compound after evaporation as a viscous oil (107 g, 96%).

Workup

  1. concentrationThe reaction mixture was concentrated in vacuo
  2. washeluted first with a mixture of methylene chloride/hexane 1:1
  3. customto remove excessive 3,4-diethoxy-3-cyclobutene-1,2-dione

Sources & evidence

ORD record
ord-fb6f29a33bdf4d0aa5fbc2cdf6ad30a1
Source dataset
uspto-grants-1999_11
Patent number
US05990307

Reaction notes

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