1,1'-Carbonyldiimidazole → HCID 54534973, compound

8.2 g of 1,1'-carbonyldiimidazole (CDI) was added to a mixture of 6.35 g of 1B and 75 ml of dry tetrahydrofuran (THF) and the mixture was stirred for 2 hours at room temperature. Then 7.5 g of alanine ethyl ester hydrochloride was added, the mixture was stirred overnight, filtered, and the filtrate was stripped of solvent. The residue was dissolved in 100 ml of a 9:1 v:v mixture of methylene chloride and ethyl acetate, the solution was filtered through silica gel, the gel was washed with 900 ml of the same solvent, then the combined filtrate and washings was stripped of solvent. The residue was a yellow oil that crystallized on standing. The crystals were washed with pentane and dried, to give N-(5-methyl-3-isoxazolylcarbonyl)alanine ethyl ester (1C), as a solid, m.p.: 65°-66° C. 1C was converted to the corresponding acid (1D, a solid, m.p.: 148°-150° C.) in the manner that 1A was converted to 1B.

1. stirringthe mixture was stirred overnight
2. filtrationfiltered
3. dissolutionThe residue was dissolved in 100 ml of a 9:1 v
4. additionv mixture of methylene chloride and ethyl acetate
5. filtrationthe solution was filtered through silica gel
6. washthe gel was washed with 900 ml of the same solvent
7. customthat crystallized
8. washThe crystals were washed with pentane
9. customdried

ORD record

ord-d9fe60ce89734c6b8c6ac535663d4bd5

Source dataset

uspto-grants-1989_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04853027