2-Furancarboxylic acid → HCID 699395, compound

Temperature

-15 °C

To a solution of furan-2-carboxylic acid (2.0 g, 17.8 mmols) and N-methylmorpholine (1.95 ml, 17.8 mmols) in anhydrous THF (10 ml), cooled at −15° C. was added dropwise under stirring an equivalent quantity of isobutylchloroformate (2.33 ml, 17.8 mmols). After 30 minutes a solution of L-leucine methylester hydrochloride (3.23 g, 17.8 mmol) and N-metylmorpholine (1.95 ml, 17.7 mmols in anhydrous THF (15 ml) was slowly added, maintaining the mixture under stirring at −15° C. for two hours. The reaction mixture was diluted with CH2Cl2 (100 ml) and washed with HCl 1N (30 ml×2), NaHCO3 saturated solution (30 ml×2), and NaCl saturated solution (30 ml). After drying the organic phase on Na2SO4 and removal of the solvent at a reduced pressure, the raw product was obtained as an oily residue which spontaneously solidified. By grinding the solid substance in petroleum ether, white crystals of either N-[(furan-2-yl) carbonyl]- L-leucine methylester were obtained: 3.32 g (80%); m.p. 88-90° C., [a] D22=−23° C. (1, methanol); IR (CHCl3): 3424, 2956, 1741, 1663, 1595, 1517, 1351, 1177 cm−1; 1H-NMR (CLCl3): d 0.95 and 1.02 [two s, 6, CH2CH(CH3)2], 1.45-2.00 [m, 3, CH2CH(CH3)2], 3.85 (s, 3, OCH3), 4.73-5.13 (m, 1, aCH), 6.39-7.45 [m, 3, furan aromatics and 6.89 (d, 1, NH, J=8 Hz)]. Calculated for C12H17NO4: C, 60.24; H 7.16; N 5.85. Found C 60.15; H 7.22; N 5.88%.

1. additionwas added dropwise
2. temperaturemaintaining the mixture
3. washwashed with HCl 1N (30 ml×2), NaHCO3 saturated solution (30 ml×2), and NaCl saturated solution (30 ml)
4. customAfter drying the organic phase
5. customon Na2SO4 and removal of the solvent at a reduced pressure
6. customthe raw product was obtained as an oily residue which

ORD record

ord-7b5982508a114a6fbdfa1927be54a1b6

Source dataset

uspto-grants-2002_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06339160B1