| 摘要 |
<p>1341827 Silyl derivatives of 7-isocyanatocephalosporanic acid KONINKLIJKE NEDERLANDSCHE GIST-EN SPIRITUSFABRIEK NV 18 Dec 1970 [18 Dec 1969] 61842/69 Heading C3S [Also in Division C2] The invention comprises 7-isocyanatocephalosporanic acid derivatives of the formula wherein R represents a hydrogen atom, a protected hydroxy group or an acyloxy group, and E represents a carboxylic protecting group such as a silyl group of general formula (R 1 ) 3 Siin which R 1 represents C 1 -C 6 alkyl, phenyl or phenyl (C 1 -C 6 ) alkyl. In particular E may represent the trimethylsilyl group. The above compounds also include those in which R is a protected hydroxy group of formula -OSi(R 1 ) 3 in which R 1 is C 1 -C 6 alkyl, phenyl or phenyl (C 1 -C 6 ) alkyl. Examples of such compounds are trimethylsilyl esters of 7-isocyanato-cephalosporanic and 7-isocyanatodesacetoxycephalosporanic acid. The 7-isocyanate cephalosporanic acid derivatives are prepared by reacting phosgene with a cephalosporanic acid derivative of formula wherein W represents a hydrogen atom or a group (R 1 ) 3 Siin which R 1 represents a C 1 -C 6 alkyl group, phenyl group or phenyl (C 1 -C 6 ) alkyl group in an inert organic solvent, to convert the grouping W-NH- into the isocyanate group without affecting the rest of the molecule. Reference has been directed by the Comptroller to Specification 1,174,335.</p> |
