反应详情

A suspension of 5 grams of 7-[[amino[4-hydroxy-3-(methoxymethyl)phenyl]acetyl]amino]-7-methoxy-3-methyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid, sodium salt and 8.5 grams of N-tert-butoxycarbonyl-L-valine chloromethyl ester, which is prepared by the general procedure described in W. German Offen. No. 2,236,620, are mixed in 100 ml of dimethylformamide and stirred for 72 hours. The mixture is diluted with ethyl acetate, washed with water and aqueous bicarbonate and again with water. The ethyl acetate portion is dried over magnesium sulfate, filtered and evaporated to give 7-[[amino[4-hydroxy-3-(methoxymethyl)phenyl]acetyl]amino]-7-methoxy-3-methyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid, N-tert-butoxycarbonyl-2-amino-3-methylbutyryloxymethyl ester from which the protecting group can be removed by standard procedures to give the title compound.

1. customis prepared by the general procedure
2. washwashed with water and aqueous bicarbonate and again with water
3. dry with materialThe ethyl acetate portion is dried over magnesium sulfate
4. filtrationfiltered
5. customevaporated