Diphosgene → Propanoic acid, 2-isocyanato-, methyl ester (9CI)

HRID 248315Notes

Reaction equation

Cl.[CH3:2][O:3][C:4](=[O:8])[C@H:5]([CH3:7])[NH2:6].Cl[C:10]([O:13]C(Cl)=O)(Cl)Cl>O1CCOCC1>[CH3:2][O:3][C:4](=[O:8])[CH:5]([N:6]=[C:10]=[O:13])[CH3:7]

Participants

Conditions

Temperature: 55 °C

Procedure

L-Alanine methyl ester hydrochloride (6.00 g., 42.99 mmole) was slurried in anhydrous 1,4-dioxane (125 ml.), treated with trichloromethylchloroformate (7.8 ml., 64.66 mmole) and heated at 55° C. for 20.5 hours. The excess trichloromethylchloroformate and 1,4-dioxane were removed from the reaction mixture by distillation under slightly reduced pressure. The resultant residue was subjected to distillation to afford the desired intermediate 2-isocyanatopropionic acid methyl ester (4.64 g., 83.6% yield) as a clear colorless liquid. B.P. 58° C. (15-20 mm Hg.). 1H-NMR (200 MHz, CDCl3) δppm =1.54, d, J=8 Hz., 3H (--CH3), 3.87, s, 3H (--OCH3), 4.13, q, J=8 Hz., 1H(--CH--CH3), IR(neat) 3000, 2960, 2270, 1745, 1455, 1445, 1385, 1305, 1230, 1110 cm-1.

Workup

customThe excess trichloromethylchloroformate and 1,4-dioxane were removed from the reaction mixture by distillation under slightly reduced pressure
distillationThe resultant residue was subjected to distillation

Sources & evidence

ORD record: ord-8f288ffbbaf04cbe9ce2858058b33d5c
Source dataset: uspto-grants-1993_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05209930

Reaction notes

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