反应详情

温度

-30 °C

Into a -30° C. cold mixture of 0.66 g (1.5 mmol) of (Z)-2-amino-α-[[1-(diphenylmethoxycarbonyl)-1-methylethoxy]imino]-4-thiazoleacetic acid in 13 ml of dry dimethylformamide, 0.63 ml (4.5 mmol) of triethylamine was dropped, followed by 0.33 ml (1.5 mmol) of diphenylchlorophosphate. After stirring at -30° C. for 1 hour, 0.42 ml (3.0 mmol) of triethylamine was dropped in, followed by the addition of 0.80 g (1.5 mmol) of (S)-3-amino-1-[[[[2-[[(3,4-dihydroxyphenyl)amino]carbonyl]hydrazino]sulfonyl]amino]carbonyl]-2-oxoazetidine. The mixture was stirred for 2 hours at -10° C. and an additional 2 hours at 0° C. The solvent was removed in vacuo and the residue was taken up in a few ml of ethyl acetate and ice water. The pH of the mixture was corrected to pH=2 the addition of dilute hydrochloric acid. The insoluble material was collected by suction1) and stirred with a few ml of ethyl acetate until it became crystalline; yield after drying in vacuo: 0.31 g. This material was used in the next step without further purification.

1. additionwas dropped
2. stirringThe mixture was stirred for 2 hours at -10° C. and an additional 2 hours at 0° C
3. customThe solvent was removed in vacuo
4. customThe insoluble material was collected by suction1) and
5. customyield
6. customafter drying in vacuo
7. customThis material was used in the next step without further purification