Claims
- 1. The process for preparing a 3-chloro-3-cephem ester of the formula ##STR9## which comprises the step of reacting a 3-hydroxy-3-cephem sulfoxide ester of the formula ##STR10## under substantially anhydrous conditions in the presence of dimethylformamide at a temperature between about -65.degree. C. and about 25.degree. C. with between about 2 and about 9 moles of a chlorinating agent selected from the group of phosphorus trichloride, phosphorus pentachloride and phosgene, per mole of said sulfoxide ester wherein R is an acyl group of the formula ##STR11## wherein R' is C.sub.1 -C.sub.6 alkyl, phenyl, or phenyl substituted by halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, nitro, or carboxy; or R is an acyl group of the formula ##STR12## wherein R" is thienyl, furyl, phenyl, or phenyl substituted by halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, nitro, or carboxy, n is 0 or 1; and when n is 1 R" is other than thienyl or furyl; R.sub.1 is hydrogen or R.sub.1 and R taken together with the nitrogen atom to which they are attached are succinimido or phthalimido; and R.sub.2 is benzyl, 4-methoxybenzyl, 3,5-dimethoxybenzyl, 3,5-dimethoxy-4-hydroxybenzyl, 4-nitrobenzyl, diphenylmethyl, 4-methoxydiphenylmethyl, 2,2,2-trichloroethyl, t-butyl, phenacyl, 4-nitrophenacyl, or methoxymethyl.
- 2. The process of claim 1 wherein phosphorus trichloride in the chlorinating agent.
- 3. The process of claim 2 wherein between about 3 and about 4 moles of phosphorus trichloride per mole of 3-hydroxy-3-cephem sulfoxide ester is used.
- 4. The process of claim 3 wherein the reaction is carried out at a temperature between about -55.degree. C. and about 0.degree. C.
- 5. The process of claim 1 wherein R is phenylacetyl, phenoxyacetyl, or thienylacetyl, R.sub.1 is hydrogen, and R.sub.2 is 2,2,2-trichloroethyl, benzyl, diphenylmethyl, 4-methoxybenzyl, or 4-nitrobenzyl
- 6. The process of claim 5 wherein R is phenoxyacetyl and R.sub.2 is 4-nitrobenzyl.
- 7. The process of claim 6 wherein between about 3 and about 4 moles of phosphorus trichloride per mole of 3-hydroxy-3-cephem sulfoxide ester is used.
- 8. The process of claim 1 wherein R and R.sub.1 are taken together and represent phthalimido.
- 9. The process of claim 8 wherein R.sub.2 is 4-nitrobenzyl.
CROSS REFERENCE TO RELATED APPLICATION
This applicatin is a continuation-in-part of application Ser. No. 714,948 filed Aug. 16, 1976, now abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3641014 |
Murphy et al. |
Feb 1972 |
|
3925372 |
Chauvette |
Dec 1975 |
|
3962227 |
Chauvette |
Jun 1976 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
714948 |
Aug 1976 |
|