Diethyl squarate → HCID 10553302, compound

HRID 1681065Notes

Reaction equation

HRID 1681065 reaction equation
[C:1]1([CH2:7][O:8][C:9](=[O:25])[NH:10][CH2:11][CH2:12][CH2:13][NH:14][CH2:15][CH2:16][P:17]([O:22][CH2:23][CH3:24])([O:19][CH2:20][CH3:21])=[O:18])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[CH2:26]([O:28][C:29]1[C:30](=O)[C:31](=[O:36])[C:32]=1[O:33]CC)[CH3:27]>C(O)C>[C:1]1([CH2:7][O:8][C:9](=[O:25])[NH:10][CH2:11][CH2:12][CH2:13][N:14]([CH2:15][CH2:16][P:17]([O:19][CH2:20][CH3:21])([O:22][CH2:23][CH3:24])=[O:18])[C:30]2[C:31](=[O:36])[C:32](=[O:33])[C:29]=2[O:28][CH2:26][CH3:27])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1

Participants

4

Reactant 2

HCID 123228Diethyl squarateHCID 10619276HCID 10619276, compound

Product 1

HCID 10553302HCID 10553302, compoundYield 89%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Procedure

A solution of [3-[[2-(diethoxyphosphinyl)ethyl]amino]propyl]carbamic acid phenylmethyl ester (3.17 g, 8.5 mmol) in absolute ethanol (40 mL) was added over 45 minutes to 3,4-diethoxy-3-cyclobutene-1,2-dione (2.3 mL, 16 mmol) dissolved ethanol (55mL). After leaving overnight, the reaction mixture was preadsorbed onto silica gel and purified by flash chromatography (7 cm diameter, gradient elution was 2.5-10% methanol in dichloromethane) to yield [3-[[2-(diethoxyphosphinyl)ethyl](2-ethoxy-3,4-dioxo-1-cyclobuten-1-yl)amino]propyl]carbamic acid phenylmethyl ester as a viscous oil (3.75 g, 89%); 1H NMR (CDCl3, 400 MHz): δ 7.35 (m, 5H), 5.45 (br m, NH), 5.09 (s, 2H), 4.80-4.71 (m, 2H), 4.16-4.09 (m, 4H), 3.90-3.48 (m, 4H), 3.23-3.20 (m, 2H), 2.16-2.05 (m, 2H), 1.85-1.79 (m, 2H), 1.47, 1.41 (t, J=7 Hz, 3H), 1.34 (t, J=7 Hz, 6H).

Workup

  1. customAfter leaving overnight
  2. custompurified by flash chromatography (7 cm diameter, gradient elution was 2.5-10% methanol in dichloromethane)

Sources & evidence

ORD record
ord-1f1ace2b6382495d991a62a850c30489
Source dataset
uspto-grants-1992_12
Patent number
US05168103

Reaction notes

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