Hydrochloric Acid → HCID 53951462, compound

Participants

Reaction Steps

To a stirred solution of (4R)-3-(3-carboxypropanoyl)-2-(2-hydroxyphenyl)-4-thiazolidinecarboxylic acid ethyl ester (compound 8a) (1.06 g) and N-methylmorpholine (0.33 ml) in 20 ml of anhydrous tetrahydrofuran, isobutyl chloroformate (0.39 ml) was added dropwise at -15° C., and stirred for additional 2 hours at this temperature. To this solution, the methanol solution of hydroxylamine (0.3 g) was added dropwise at -50° C. The reaction mixture was stirred for 1 hour at room temperature, acidified with N hydrochloric acid, and extracted with ethyl acetate. The organic layer was washed with saturated sodium chloride solution, dried over anhydrous magnesium sulfate, and concentrated in vacuo. The residual oil was purified by silica gel column chlromatography to give 0.7 g (63%) of the titled compound. IR (KBr, cm-1) 3220, 1727, 1625, 1595, 1200, 1092, 753. NMR (acetone-d6, δ): 1.24 (3H, t, J=7.5 Hz, CO2CH2CH3), 2.17-3.07 (4H, m, CO--CH2)2CO), 3.30 (1H, ABq (A part), d, J=10.0, 2.0 Hz, C5 --HA), 3.47 (1H, ABq (B part), d, J=10.0, 7.0 Hz, C5 --HB), 4.14 (2H, q, J=7.5 Hz, CO2CH2), 5.18 (1H, dd, J=2.0, 7.0 Hz, C4 --H), 6.40 (1H, S, C2 --H), 6.88-7.27 (4H, m, arom. H), 8.60 (2H, br. s, NHOH), 9.77 (1H, br. s, OH )

Provenance & Evidence