Diethyl squarate → HCID 10806855, compound

HRID 2255483Notes

Reaction equation

HRID 2255483 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:27])[NH:19][CH2:20][CH2:21][CH2:22][NH:23][CH2:24][C:25]#[N:26])([CH3:16])[CH3:15]>C(O)C>[CH3:16][C:14]([O:17][C:18](=[O:27])[NH:19][CH2:20][CH2:21][CH2:22][N:23]([CH2:24][C:25]#[N:26])[C:4]1[C:5](=[O:12])[C:6](=[O:11])[C:7]=1[O:8][CH2:9][CH3:10])([CH3:13])[CH3:15]

Participants

4

Reactant 2

HCID 123228Diethyl squarateHCID 10560546Carbamic acid, [3-[(cyanomethyl)amino]propyl]-, 1,1-dimethylethyl ester

Product 1

HCID 10806855HCID 10806855, compoundYield 90.2%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Procedure

A solution of 3,4-diethoxy-3-cyclobutene-1,2-dione (2.6 mL, 18 mmol) in absolute ethanol (90 mL) was treated with [3-(cyanomethylamino)propyl]carbamic acid 1,1-dimethylethyl ester (3.90 g, 18 mmol) in ethanol (30 mL) over 90 min. After 40 hours the reaction mixture was evaporated, dissolved in dichloromethane, preadsorbed onto silica gel, and purified by flash chromatography (7 cm diameter, gradient elution with 0-5% methanol in dichloromethane) to yield [3-[(cyanomethyl)-(2-ethoxy-3,4-dioxo-1-cyclobuten-1-yl)amino]propyl]carbamic acid 1,1-dimethylethyl ester as a yellow oil (5.48 g, 90%); IR (neat, cm-1): 3360, 1800; MS (+FAB): 282 (76), 238 (98), 158 (100); 1H NMR (CDCl3, 400 MHz): δ 4.81 (q, J=7 Hz, 2H), 4.75 (br s, NH), 4.45, 3.66 (s, 2H), 3.84, 3.60 (br m, 2H), 3.26-3.15 (m, 2H), 1.91 (p, J=6.5 Hz, 2H), 1.50 (t, J=7 Hz, 3H), 1.45 (s, 9H).

Workup

  1. customAfter 40 hours the reaction mixture was evaporated
  2. dissolutiondissolved in dichloromethane
  3. custompurified by flash chromatography (7 cm diameter, gradient elution with 0-5% methanol in dichloromethane)

Sources & evidence

ORD record
ord-5743054727df44bfab2054b7ea21e3dc
Source dataset
uspto-grants-1993_08
Patent number
US05240946

Reaction notes

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