Diethyl squarate → HCID 10504762, compound

HRID 1681075Notes

Reaction equation

HRID 1681075 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.[CH3:13][C:14]([O:17][C:18](=[O:35])[NH:19][CH2:20][CH2:21][CH2:22][CH2:23][NH:24][CH2:25][CH2:26][P:27]([O:32][CH2:33][CH3:34])([O:29][CH2:30][CH3:31])=[O:28])([CH3:16])[CH3:15]>C(O)C>[CH3:13][C:14]([O:17][C:18](=[O:35])[NH:19][CH2:20][CH2:21][CH2:22][CH2:23][N:24]([CH2:25][CH2:26][P:27]([O:29][CH2:30][CH3:31])([O:32][CH2:33][CH3:34])=[O:28])[C:4]1[C:5](=[O:12])[C:6](=[O:11])[C:7]=1[O:8][CH2:9][CH3:10])([CH3:15])[CH3:16]

Participants

4

Reactant 2

HCID 123228Diethyl squarateHCID 10498188HCID 10498188, compound

Product 1

HCID 10504762HCID 10504762, compoundYield 90.4%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Procedure

To a solution of 3,4-diethoxy-3-cyclobutene-1,2-dione (5.8 mL, 39 mmol) in absolute ethanol (200 mL) prepared under nitrogen, was added a solution of [4-[[2-(diethoxyphosphinyl)ethyl]amino]butyl]carbamic acid 1,1-dimethylethyl ester (13.7 g, 39 mmol) in ethanol (75 mL) over 1.75 hour. The reaction mixture was stirred at room temperature overnight and then concentrated in vacuo. The residue was dissolved in chloroform (150 mL), preadsorbed onto silica gel, and purified by flash chromatography (9 cm diameter, elution with 2.5% methanol in dichloromethane) to yield [4-[[2-(diethoxyphosphinyl)ethyl](2-ethoxy-3,4-dioxo-1-cyclobuten-1-yl)amino]-butyl]carbamic acid 1,1-dimethylethyl ester as a yellow viscous oil (16.8 g, 90%).

Workup

  1. concentrationconcentrated in vacuo
  2. dissolutionThe residue was dissolved in chloroform (150 mL)
  3. custompurified by flash chromatography (9 cm diameter, elution with 2.5% methanol in dichloromethane)

Sources & evidence

ORD record
ord-d96f491610b046bab098b421f1a91d30
Source dataset
uspto-grants-1992_12
Patent number
US05168103

Reaction notes

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