Diethyl squarate → HCID 10552641, compound

HRID 2255476Notes

Reaction equation

HRID 2255476 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][CH:21]([OH:34])[CH2:22][NH:23][CH2:24][CH2:25][P:26]([O:31][CH2:32][CH3:33])([O:28][CH2:29][CH3:30])=[O:27])([CH3:16])[CH3:15]>C(O)C>[CH3:13][C:14]([O:17][C:18](=[O:35])[NH:19][CH2:20][CH:21]([OH:34])[CH2:22][N:23]([CH2:24][CH2:25][P:26]([O:31][CH2:32][CH3:33])([O:28][CH2:29][CH3:30])=[O:27])[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 10713104HCID 10713104, compound

Product 1

HCID 10552641HCID 10552641, compoundYield 70%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Procedure

To a solution of 3,4-diethoxy-3-cyclobutene-1,2-dione (5.0 mL, 34 mmol) in absolute ethanol (180 mL) prepared under nitrogen, was added a solution of [3-[[2-(diethoxyphosphinyl)ethyl]amino]-2-hydroxypropyl]carbamic acid 1,1-dimethylethyl ester (12.11 g, 34 mmol) in ethanol (60 mL) over 1 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 (7 cm diameter, gradient elution with 2.5-15% methanol in dichloromethane) to yield [3-[[2-(diethoxyphosphinyl)ethyl](2-ethoxy-3,4-dioxo-1-cyclobuten-1-yl)amino]-2-hydroxypropyl]carbamic acid 1,1-dimethylethyl ester as a clear viscous oil (11.34 g, 70%); IR (neat, cm-1): 3350, 1800, 1700: 1H NMR (CDCl3, 400 MHz): δ 5.37, 5.19 (br s, NH), 4.82-4.72 (m, 3H), 4.16-3.11 (m, 11H), 2.24-2.14 (m, 2H), 1.47-1.43 (m, 12H), 1.32 (t, J=7 Hz, 6H).

Workup

  1. concentrationconcentrated in vacuo
  2. dissolutionThe residue was dissolved in chloroform (150 mL)
  3. custompurified by flash chromatography (7 cm diameter, gradient elution with 2.5-15% methanol in dichloromethane)

Sources & evidence

ORD record
ord-0e6e0c45fad84db9a78dfcb0f209f131
Source dataset
uspto-grants-1993_08
Patent number
US05240946

Reaction notes

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