Hydrochloric Acid → N-iodopropargyloxycarbonyl glycine

Participants

Reaction Conditions

Reaction Steps

N-Iodopropargyloxycarbonyl glycine methyl ester (Compound 2, 8.03 g., 27.03 mmole) was dissolved in 100 ml. of tetrahydrofuran, cooled to 0° C. with an ice bath and treated during 15 minutes with 30.5 ml. of 1M aqueous lithium hydroxide. The reaction mixture was stirred at 0° C. for 3/4 hr. or until the starting material was no longer present. The reaction progress was monitored by thin layer chromatography (silica gel, methylene chloride/acetic acid 90:10). After the reaction was complete, the aqueous solution was acidified (pH=2) with 10% aqueous potassium hydrogen sulfate (100 ml) and 3N aqueous hydrogen chloride (10 ml.). This mixture was extracted several times with diethyl ether. The ether layers were combined and washed with water, dried over magnesium sulfate, filtered and concentrated under reduced pressure to afford N-iodopropargyloxycarbonyl glycine (Compound 1) as a pale amber oil, which crystallized upon standing (6.63 g., 86.7% yield after drying in vacuo over P2O5). m.p. 108° -110° C. 1H-NMR (200 MHz., DMSOd6) δppm =3.67., d, 2H (--NH--CH2 --), 4.76, s, 2H (C--CH2 --O), 7.66, t, 1H (NH).

Provenance & Evidence