Ethylmorpholine → HCID 11752641, compound

Participants

Reaction Steps

The carboxylic acid from step 3 (239 mg, 0.49 mmol) was dissolved in 4 ml of THF. After that, ethyl chloroformate (64 mg, 0.59 mmol) and N-ethylmorpholine (79.7 mg, 0.69 mmol) were added at 0° C. and preactivation was carried out at this temperature for one hour. O-Trimethylsilylhydroxylamine (208 mg, 1.98 mmol) was then added and the mixture was stirred overnight at from 0° C. to RT. The solvent was removed under reduced pressure and the residue was taken up in ethyl acetate; this solution was extracted by shaking with dilute HCl, water and sodium carbonate solution. The residue was dissolved, for direct preparative RP-HPLC, in a small quantity of a mixture of acetonitrile, water and 0.01% trifluoroacetic acid. Resulting fractions were pooled, acetonitrile was removed under reduced pressure and the remaining aqueous phase was freeze-dried. Yield: 4.5 mg; unreacted carboxylic acid and other, not specifically characterized, byproducts are obtained in addition. Analytical data are given in Table 1.

Provenance & Evidence