Diethyl squarate synthesis
- Product Name:Diethyl squarate
- CAS Number:5231-87-8
- Molecular formula:C8H10O4
- Molecular Weight:170.16
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5231-87-8
1. Squaric acid (1.0023 g) was dissolved in 30 mL of anhydrous ethanol and heated to reflux overnight. After the reaction was completed, the reaction solution was concentrated and purified by fast column chromatography to give 0.7430 g of diethyl ester of squaric acid in 50% yield. 2. The resulting diethyl (ethyl) squarate, 2-aminopyridine (100 mg, 0.588 mmol) and triethylamine (10 drops) were dissolved in dichloromethane (10 mL) and stirred at room temperature overnight. After completion of the reaction, the reaction solution was concentrated under reduced pressure and purified by fast column chromatography (petroleum ether/ethyl acetate, 2:1) to afford compound 6 as a white solid in 73% yield. 3. The NMR data of compound 6 were as follows: 1H NMR (400 MHz, acetone-d6) δ 10.26 (s, 1H), 8.50-8.29 (m, 1H), 7.98-7.78 (m, 1H), 7.68 (d, J = 8.3 Hz, 1H), 7.14 (dd, J = 6.9, 5.3 Hz, 1H), 4.85 (q, J = 7.1 Hz, 2H), 1.48 (t, J = 7.1 Hz, 3H); 13C NMR (100 MHz, acetone-d6) δ 186.42, 180.83, 170.33, 166.86, 152.22, 149.33, 139.43, 120.17, 113.63, 70.65, 16.06.
122-51-0
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5231-87-8
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Yield:5231-87-8 97%
Reaction Conditions:
in ethanol at 80; for 48 h;
Steps:
2.2.8 Synthesis of 2-diethoxy-1-cyclobutene-3,4-dione
To a stirred solution of 3,4-dihydroxycyclobut-3-ene-1,2-dione (3.00g, 26.4mmol) in anhydrous ethanol (150mL) was added triethyl orthoformate (72.2mmol, 12.0mL) at room temperature. The mixture was heated to reflux at 80°C and left for 48h before being concentrated under reduced pressure. The crude yellow oil was purified by flash chromatography (DCM) to yield the title compound (3.57g, 97%) as an intensely yellow oil which was not purified further; 1H NMR (300MHz, CDCl3): δ 4.72 (m, 4H), 1.44 (t, J=87.9Hz, 6H). Data are in agreement with that previously reported [43].
References:
Ryan, Philip;Shi, Yun;von Itzstein, Mark;Rudrawar, Santosh [Bioorganic Chemistry,2021,vol. 110,art. no. 104738]
79-37-8
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5231-87-8
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61699-62-5
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5231-87-8
224 suppliers
$10.00/1g
64-17-5
856 suppliers
$10.00/50g
122-51-0
518 suppliers
$10.00/5ml
2892-51-5
415 suppliers
$5.00/1g
5231-87-8
224 suppliers
$10.00/1g