Diethyl squarate → HCID 10553302, compound

HRID 2255474Notes

Reaction equation

HRID 2255474 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

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 (55 mL). After leaving overnight, the reaction mixture was preadsorbed onto silica gel and purified by flash chromotography (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, 2 H), 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 chromotography (7 cm diameter, gradient elution was 2.5-10% methanol in dichloromethane)

Sources & evidence

ORD record
ord-45a989912a274f09bfc92f1c05b6f3a1
Source dataset
uspto-grants-1993_08
Patent number
US05240946

Reaction notes

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