反応 #55421

反応方程式

7-amino-3-[1-(2-carbamoylethyl)tetrazol-5-ylthiomethyl]-3-cephem-4-carboxylic acid

O-t-butyldiisopropylpseudourea

→

7-amino-3-[1-(2-carbamoylethyl)tetrazol-5-ylthiomethyl]-3-cephem-4-carboxylic acid t-butyl ester

溶媒

methylene chloride

methylene chloride

反応条件

後処理

1. 1
   workup.ADDITIONTo a suspension of 19.3 g
2. 2
   その他The precipitate is removed by filtration
3. 3
   その他the filtrate is evaporated
4. 4
   その他to give a residue which
5. 5
   ろ過of benzene and filtered again
6. 6
   抽出The filtrate is extracted with three 100 ml
7. 7
   workup.ADDITIONthe pH is adjusted to 7.5 by addition of solid sodium bicarbonate
8. 8
   その他The organic layer is separated
9. 9
   抽出the aqueous phase is extracted with two 150 ml
10. 10
    乾燥The combined extracts are dried (MgSO4)
11. 11
    ろ過filtered
12. 12
    その他evaporated to dryness

実験手順

To a suspension of 19.3 g. (0.05 mol.) of 7-amino-3-[1-(2-carbamoylethyl)tetrazol-5-ylthiomethyl]-3-cephem-4-carboxylic acid in 500 ml. of dry methylene chloride is added in one portion 30.0 g. (0.15 mol.) of O-t-butyldiisopropylpseudourea in 50 ml. of methylene chloride and the mixture is stirred at ambient temperature for 24 hours. The precipitate is removed by filtration and the filtrate is evaporated to give a residue which is taken up in 200 ml. of benzene and filtered again. The filtrate is extracted with three 100 ml. portions of cold 1N hydrochloric acid. The aqueous extracts are layered with ethyl acetate and the pH is adjusted to 7.5 by addition of solid sodium bicarbonate. The organic layer is separated and the aqueous phase is extracted with two 150 ml. portions of ethyl acetate. The combined extracts are dried (MgSO4), filtered and evaporated to dryness to give 7-amino-3-[1-(2-carbamoylethyl)tetrazol-5-ylthiomethyl]-3-cephem-4-carboxylic acid t-butyl ester.

出典