Pyridine → HCID 13572150, compound

Participants

Reaction Steps

A solution of 0.1 mol of p-aminobenzaldehyde ethylene glycol acetal in 100 mL of anhydrous THF is added dropwise over 10 minutes to a solution of 0.1 mol glycine methyl ester isocyanate and 0.35 mol pyridine in 100 mL THF at room temperature under N2. The yellow reaction mixture is stirred at room temperature for 2 hours. After 1/2 hour a yellow-orange precipitate begins to form. After 2 hours the solvent is removed by rotary evaporator to give an orange, semisolid mass. A solution of 0.11 mmol hydroxylamine hydrochloride and 0.1 mol trimethyl orthoformate in CH3OH is added, and the reaction mixture is heated to reflux under N2 for 1 hour. The reaction mixture is reduced to about 1/4 volume by rotary evaporator, and water is added. Pale yellow crystals of product form, which are isolated by filtration and dried overnight in a vacuum oven at 50°-55° C. The yield of crude product (mp 158°-161° C.): 70-75 %. The product is purified by recrystallization from a 10:6:1 solution of CH3OH:H2O: compound. The product is washed with cold water and dried in a vacuum oven at 50° C. to give off-white crystals of N-[4-hydroxyiminomethyl)phenyl]-N'-methoxycarbonylmethylurea, mp. 167.5°-168.5° C. Elemental analysis: calcd. C 52.59, H 5.22, N 16.72; found C 52.38, H 5.16, N 16.65. 1H NMR (acetone-d6): δ10.15 s, 1H, --NOH; 8.4 s, 1H, --NH--; 8.1 s/d, 1H, --CH=N; 7.55 bs, 4H, phenyl; 6.21 s/d, 1H, --NH--; 4.02 s/d, 2H, --CH2 --; 3.74 s, 3H, CH3O--. 13C NMR (acetone-d6): δ172, --COO--; 156, --NCON--; 149, --CH=N--; 119, 128, 142, phenyl; 52, CH 3 O--; 42, --CH2 --. UV-vis (CH3OH): λmax =279 nm, ε=2.90×104.

Provenance & Evidence