Triethylamine → HCID 178501430, compound

Temperature

0 °C

In 200 ml of dry chloroform was suspended 10.0 g of L-histidine methyl ester dihydrochloride, and to the suspension were successively added 18.4 ml of triethylamine and 10.2 g of 4-methoxybenzyloxycarbonylazide under cooling. The mixture was stirred for 16 hours at 0° C., and then the reaction mixture was evaporated under reduced pressure. To the residue was added a 5% aqueous sodium bicarbonate solution, and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with water, dried over anhydrous magnesium sulfate, and evaporated under reduced pressure. The residue was purified by silica gel flash column chromatography (eluent: chloroform/methanol=10/1) to obtain 11.0 g of N-(4-methoxybenzyloxycarbonyl)-L-histidine methyl ester as a yellow oil. In 112 ml of methanol was dissolved 10.9 g of the ester compound obtained, and to the solution was added 9.9 ml of hydrazine monohydrate. The mixture was stirred for 4 hours at room temperature, and then the reaction mixture was evaporated under reduced pressure. The residue was washed with ethanol and then dried at below 40° C. to obtain 4.9 g of N-(4-methoxybenzyloxycarbonyl)-L-histidine hydrazide as a white powder.

1. temperatureunder cooling
2. customthe reaction mixture was evaporated under reduced pressure
3. additionTo the residue was added a 5% aqueous sodium bicarbonate solution
4. extractionthe mixture was extracted with ethyl acetate
5. washThe ethyl acetate layer was washed with water
6. dry with materialdried over anhydrous magnesium sulfate
7. customevaporated under reduced pressure
8. customThe residue was purified by silica gel flash column chromatography (eluent: chloroform/methanol=10/1)

ORD record

ord-b3987510b65f4cd184853af7fa6d0f5f

Source dataset

uspto-grants-1989_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04870183