64485-82-1

Usage

Uses

Ethyl 2-amino-α-(hydroxyimino)-4-thiazoleacetate may be used in chemical synthesis.

InChI:InChI=1/C7H9N3O3S/c1-2-13-6(11)5(10-12)4-3-14-7(8)9-4/h3,12H,2H2,1H3,(H2,8,9)/b10-5-

Synthetic route

thiourea (17356-08-0) + ethyl 4-chloro-2-hydroxyimino-3-oxo-butyrate (66338-95-2) → (Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1)

Conditions	Yield
In ethanol; water at 20℃; for 1h;
In N,N-dimethyl acetamide at 20℃; for 3h;	8.9 g

ethyl 2-(hydroxyimino)-3-oxybutyrate (66508-93-8) → (Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1)

Conditions	Yield
Multi-step reaction with 2 steps 1: SO2Cl2; glac. AcOH / 1 h / 58 - 60 °C 2: 8.9 g / N,N-dimethyl-acetamide / 3 h / 20 °C View Scheme
With sulfuryl dichloride; thiourea; 2,3-Dimethylaniline In diethyl ether; ethanol; dichloromethane

ethyl acetoacetate (141-97-9) + 3,7,8,8-tetramethyl-non-6ξ-en-1-yn-3-ol → (Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1)

Conditions	Yield
Multi-step reaction with 3 steps 1: aq. NaNO2; glac. AcOH / 0.5 h / 10 °C 2: SO2Cl2; glac. AcOH / 1 h / 58 - 60 °C 3: 8.9 g / N,N-dimethyl-acetamide / 3 h / 20 °C View Scheme

ethyl acetoacetate (141-97-9) → (Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1)

Conditions	Yield
Multi-step reaction with 2 steps 1.1: sodium nitrite; acetic acid / water / 3.7 h / 20 °C 2.1: sulfuric acid / water; methanol; ethanol / 15 - 20 °C 2.2: 3407 / 2.5 h / 20 - 28 °C View Scheme

ethyl 2-(hydroxyimino)-3-oxybutyrate (66508-93-8) + thiourea (17356-08-0) → (Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1)

Conditions	Yield
Stage #1: ethyl 2-(hydroxyimino)-3-oxybutyrate With sulfuric acid In methanol; ethanol; water at 15 - 20℃; Stage #2: thiourea With tetrabutylammomium bromide; potassium carbonate In methanol at 20 - 28℃; for 2.5h;

trityl chloride (76-83-5) + (Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → ethyl 2-(2-tritylaminothiazol-4-yl)-(Z)-2-(tritylhydroxyimino)acetate (69689-86-7)

Conditions	Yield
Stage #1: (Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate With triethylamine In acetonitrile at 20 - 25℃; for 0.166667h; Stage #2: trityl chloride In acetonitrile at 55 - 60℃; for 1h;	99.2%
With triethylamine In N,N-dimethyl-formamide at 50℃;	85%
With triethylamine In N,N-dimethyl-formamide at 50℃;	85%

sodium hydrogencarbonate (144-55-8) + 3-bromopropylamine tert-butylcarbamate (83948-53-2) + (Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → ethyl (2Z)-2-(2-aminothiazol-4-yl)-2-(3-N-tert-butoxycarbonylaminopropoxyimino)acetate

Conditions	Yield
With potassium carbonate In water; ethyl acetate; N,N-dimethyl-formamide	96%
With potassium carbonate In water; ethyl acetate; N,N-dimethyl-formamide	96%

triphenylmethyl alcohol (76-84-6) + (Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → ethyl (2-aminothiazol-4-yl)-2-(Z)-(trityloxyimino)acetate (128438-00-6)

Conditions	Yield
Stage #1: triphenylmethyl alcohol; (Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate With boron trifluoride diethyl etherate; acetic acid In water; ethyl acetate at -5 - 45℃; for 25.5h; Inert atmosphere; Stage #2: With sodium hydrogencarbonate In water	92%

chloroacetyl chloride (79-04-9) + (Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → 4-<(Z)-1-Carbethoxy-1-hydroxyimino>methyl-2-chloroacetamidothiazole (94418-08-3)

Conditions	Yield
In N,N-dimethyl acetamide 1) 30 min., 0 deg C, 2) 30 min., room temper.;	88%

Cyclopentyl bromide (137-43-9) + (Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → ethyl (Z)-2-(2-aminothiazol-4-yl)-2-(cyclopentyloxyimino)acetate (74439-94-4)

Conditions	Yield
With potassium carbonate In dimethyl sulfoxide at 50℃; for 20h;	81%

benzimidazo[2,1-a]benz[de]isoquinoline-7-one-12-carboxylic acyl chloride + (Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → ethyl (Z)-2-(hydroxyimino)-2-(2-(benzimidazo[2,1-α]benz[de]isoquinoline-7-one-12-carboxamido)thiazol-4-yl)acetate

Conditions	Yield
In chloroform; N,N-dimethyl-formamide at 20℃; for 0.5h;	21%

trityl chloride (76-83-5) + (Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → ethyl (Z)-2-hydroxyimino-2-(2-triphenylmethylaminothiazol-4-yl)acetate (66338-99-6)

Conditions	Yield
With triethylamine In N,N-dimethyl-formamide for 1h;
With triethylamine In N,N-dimethyl-formamide at 20℃;

(Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → 2-(2-Amino-1,3-thiazol-4-yl)-2-(hydroxyimino)acetic acid (66338-96-3)

Conditions	Yield
With sodium hydroxide In ethanol at 45℃; for 0.5h;
With sodium hydroxide In ethanol
With sodium hydroxide In ethanol

N,N-dimethyl acetamide (127-19-5) + trityl chloride (76-83-5) + (Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → (Z)-(2-aminothiazol-4-yl)-2-trityloxyiminoacetic acid N,N-dimethylacetamide solvate

Conditions	Yield
Yield given. Multistep reaction;

trityl chloride (76-83-5) + (Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → ethyl 2-(2-tritylaminothiazol-4-yl)-(Z)-2-(tritylhydroxyimino)acetate (69689-86-7) + ethyl (2-aminothiazol-4-yl)-2-(Z)-(trityloxyimino)acetate (128438-00-6)

Conditions	Yield
With potassium tert-butylate In tetrahydrofuran 1.) r.t., 2 h, 2.) 40 deg C, 4 h; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

trityl chloride (76-83-5) + (Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → (Z)-2-(2-aminothiazol-4-yl)-2-(triphenylmethoxyimino)acetic acid (128438-01-7) + (Z)-2-(trityloxyimino)-2-(2-tritylamino-4-thiazolyl)acetic acid (68786-47-0)

Conditions	Yield
With potassium tert-butylate 1.) THF, r.t., 2 h; 40 deg C, 4 h, 2.) EtOH, reflux, 4 h; Multistep reaction. Yields of byproduct given. Title compound not separated from byproducts;
With potassium tert-butylate 1.) THF, r.t., 2 h; 40 deg C, 4 h, 2.) EtOH, reflux, 4 h; Yield given. Multistep reaction. Title compound not separated from byproducts;

trityl chloride (76-83-5) + (Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → ethyl (2-aminothiazol-4-yl)-2-(Z)-(trityloxyimino)acetate (128438-00-6)

Conditions	Yield
With potassium tert-butylate In tetrahydrofuran
In tetrahydrofuran; chloroform; mineral oil

(Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → cefdinir (91832-40-5)

Conditions	Yield
Multi-step reaction with 5 steps 1: 52.2 percent / TEA / CHCl3 / 1.5 h / 20 °C 2: 97.6 percent / aq. NaOH / dioxane / 2 h / 100 - 110 °C 3: 92.4 percent / N,N-dimethylaniline; POCl3 / CH2Cl2 / 1.5 h / -15 - -10 °C 4: TFA; anisole / CH2Cl2 / 0 - 5 °C 5: 2.54 g / aq. HCOOH / 3 h / 20 °C View Scheme

(Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → 7β-[(Z)-2-(2-amino-4-thiazolyl)-2-(trityloxyamino)acetamido]-3-vinylcephem-4-carboxylic acid (128454-32-0)

Conditions	Yield
Multi-step reaction with 4 steps 1: 52.2 percent / TEA / CHCl3 / 1.5 h / 20 °C 2: 97.6 percent / aq. NaOH / dioxane / 2 h / 100 - 110 °C 3: 92.4 percent / N,N-dimethylaniline; POCl3 / CH2Cl2 / 1.5 h / -15 - -10 °C 4: TFA; anisole / CH2Cl2 / 0 - 5 °C View Scheme

(Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → sodium 2-(2-tritylaminothiazol-4-yl)-(Z)-2-(tritylhydroxyimino)acetate

Conditions	Yield
Multi-step reaction with 2 steps 1: 52.2 percent / TEA / CHCl3 / 1.5 h / 20 °C 2: 97.6 percent / aq. NaOH / dioxane / 2 h / 100 - 110 °C View Scheme

(Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → diphenylmethyl 7β-[2-(2-tritylaminothiazol-4-yl)-(Z)-2-tritylhydroxyimino]-3-vinyl-3-cephem-4-carboxylate (123201-39-8)

Conditions	Yield
Multi-step reaction with 3 steps 1: 52.2 percent / TEA / CHCl3 / 1.5 h / 20 °C 2: 97.6 percent / aq. NaOH / dioxane / 2 h / 100 - 110 °C 3: 92.4 percent / N,N-dimethylaniline; POCl3 / CH2Cl2 / 1.5 h / -15 - -10 °C View Scheme

(Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → (Z)-2-(2-aminothiazol-4-yl)-2-(triphenylmethoxyimino)acetic acid (128438-01-7)

Conditions	Yield
Multi-step reaction with 2 steps 1: T-BuOK / tetrahydrofuran 2: KOH / ethanol / Saponification View Scheme
Multi-step reaction with 2 steps 1.1: boron trifluoride diethyl etherate / acetic acid / ethyl acetate; water / 25.5 h / -5 - 45 °C / Inert atmosphere 2.1: potassium hydroxide; water / ethanol / 20 - 30 °C / Reflux 2.2: pH 4 - 5 View Scheme

(Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → (Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(triphenylmethoxyimino)acetic acid (189449-52-3)

Conditions	Yield
Multi-step reaction with 3 steps 1: T-BuOK / tetrahydrofuran 2: KOH / ethanol / Saponification 3: 71 percent / N-chlorosuccinimide / dimethylformamide / 20 °C View Scheme

(Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → MC-02,479

Conditions

Yield

Multi-step reaction with 7 steps 1.1: T-BuOK / tetrahydrofuran 2.1: KOH / ethanol / Saponification 3.1: 71 percent / N-chlorosuccinimide / dimethylformamide / 20 °C 4.1: 65 percent / pyridine; POCl3 / tetrahydrofuran / 0.5 h / cooling 5.1: 95 percent / sodium hydrogen sulfide hydrate / dimethylformamide / 0.25 h / -20 °C 6.1: 26 percent / dimethylformamide / 20 °C 7.1: trifluoroacetic acid / CH2Cl2 / 1.5 h 7.2: formic acid / H2O / 4 h / 20 °C View Scheme

(Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → (7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(triphenylmethoxyimino)acetamido]-3-chloro-3-cephem-4-carboxylate diphenylmethyl ester (189449-54-5)

Conditions	Yield
Multi-step reaction with 4 steps 1: T-BuOK / tetrahydrofuran 2: KOH / ethanol / Saponification 3: 71 percent / N-chlorosuccinimide / dimethylformamide / 20 °C 4: 65 percent / pyridine; POCl3 / tetrahydrofuran / 0.5 h / cooling View Scheme

(Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → (7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(triphenylmethoxyimino)acetamido]-3-mercapto-3-cephem-4-carboxylate diphenylmethyl ester (189449-55-6)

Conditions	Yield
Multi-step reaction with 5 steps 1: T-BuOK / tetrahydrofuran 2: KOH / ethanol / Saponification 3: 71 percent / N-chlorosuccinimide / dimethylformamide / 20 °C 4: 65 percent / pyridine; POCl3 / tetrahydrofuran / 0.5 h / cooling 5: 95 percent / sodium hydrogen sulfide hydrate / dimethylformamide / 0.25 h / -20 °C View Scheme

(Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → (7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(triphenylmethoxyimino)acetamido]-3-[3-(N-tert-butoxycarbonylaminoethylthiomethyl)pyrid-4-ylthio]-3-cephem-4-carboxylate diphenylmethyl ester (189449-58-9)

Conditions	Yield
Multi-step reaction with 6 steps 1: T-BuOK / tetrahydrofuran 2: KOH / ethanol / Saponification 3: 71 percent / N-chlorosuccinimide / dimethylformamide / 20 °C 4: 65 percent / pyridine; POCl3 / tetrahydrofuran / 0.5 h / cooling 5: 95 percent / sodium hydrogen sulfide hydrate / dimethylformamide / 0.25 h / -20 °C 6: 26 percent / dimethylformamide / 20 °C View Scheme

(Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → S-(2-benzothiazolyl) 2-(2-aminothiazol-4-yl)-2(Z)-trityloxyiminothioacetate (143183-03-3)

Conditions	Yield
Multi-step reaction with 2 steps 2: 1.) Ph3P / 1.) CH2Cl2, r.t., 40 min, 2.) r.t., 1.5 h View Scheme

(Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → (6R,7R)-7-{2-(2-Amino-thiazol-4-yl)-2-[(Z)-trityloxyimino]-acetylamino}-3-methoxymethyl-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid (S)-1-(2,2-dimethyl-propionyloxy)-ethyl ester (152401-10-0)

Conditions	Yield
Multi-step reaction with 3 steps 2: 1.) Ph3P / 1.) CH2Cl2, r.t., 40 min, 2.) r.t., 1.5 h 3: dimethylformamide; propan-1-ol / 2 h / Ambient temperature View Scheme

(Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → (6R,7R)-7-{2-(2-Amino-thiazol-4-yl)-2-[(Z)-hydroxyimino]-acetylamino}-3-methoxymethyl-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid (S)-1-(2,2-dimethyl-propionyloxy)-ethyl ester; compound with toluene-4-sulfonic acid

Conditions	Yield
Multi-step reaction with 4 steps 2: 1.) Ph3P / 1.) CH2Cl2, r.t., 40 min, 2.) r.t., 1.5 h 3: dimethylformamide; propan-1-ol / 2 h / Ambient temperature 4: 86 percent / propan-1-ol / 1.5 h / 80 °C View Scheme

(Z)-ethyl 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetate (64485-82-1) → (Z)-2-(2-aminothiazol-4-yl)-2-(cyclopentyloxyimino)acetic acid (74439-96-6)

Conditions	Yield
Multi-step reaction with 2 steps 1: 81 percent / potassium carbonate / dimethylsulfoxide / 20 h / 50 °C 2: 80 percent / aq. NaOH / H2O; ethanol / 16 h / Ambient temperature View Scheme

Upstream product

• 17356-08-0 thiourea 
• 66338-95-2 ethyl 4-chloro-2-hydroxyimino-3-oxo-butyrate 
• 66508-93-8 ethyl 2-(hydroxyimino)-3-oxybutyrate 
• 141-97-9 ethyl acetoacetate 

Downstream Products

• 69689-86-7 ethyl 2-(2-tritylaminothiazol-4-yl)-(Z)-2-(tritylhydroxyimino)acetate 
• 128438-00-6 ethyl (2-aminothiazol-4-yl)-2-(Z)-(trityloxyimino)acetate 
• 128438-01-7 (Z)-2-(2-aminothiazol-4-yl)-2-(triphenylmethoxyimino)acetic acid 
• 68786-47-0 (Z)-2-(trityloxyimino)-2-(2-tritylamino-4-thiazolyl)acetic acid 
• 86299-46-9 ethyl (Z)-2-(2-aminothiazole-4-yl)-2-(2-tert.-butoxycarbonylprop-2-oxyimino) acetate 
• 94418-20-9 4-<(Z)-1-Acetonyloxycarbonyl-1-trityloxyimino>methyl-2-chloroacetamidothiazole N-Oxide 
• 94418-11-8 4-<(Z)-1-Acetonyloxycarbonyl-1-trityloxyimino>methyl-2-chloroacetamidothiazole 
• 94418-19-6 4-<(Z)-1-Carboxy-1-trityloxyimino>methyl-2-chloroacetamidothiazole 
• 94418-10-7 4-<(Z)-1-Carbethoxy-1-trityloxyimino>methyl-2-chloroacetamidothiazole 
• 94418-09-4 4-<(Z)-1-Carboxy-1-trityloxyimino>methyl-2-chloroacetamidothiazole 
• 152401-10-0 (6R,7R)-7-{2-(2-Amino-thiazol-4-yl)-2-[(Z)-trityloxyimino]-acetylamino}-3-methoxymethyl-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid (S)-1-(2,2-dimethyl-propionyloxy)-ethyl ester 
• 143183-03-3 S-(2-benzothiazolyl) 2-(2-aminothiazol-4-yl)-2(Z)-trityloxyiminothioacetate 
• 189449-58-9 (7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(triphenylmethoxyimino)acetamido]-3-[3-(N-tert-butoxycarbonylaminoethylthiomethyl)pyrid-4-ylthio]-3-cephem-4-carboxylate diphenylmethyl ester 
• 189449-55-6 (7R)-7-[(Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(triphenylmethoxyimino)acetamido]-3-mercapto-3-cephem-4-carboxylate diphenylmethyl ester 

Relevant academic research and scientific papers

Synthetic method for ceftazidime side chain acid ethyl ester

The invention belongs to the technical field of medicine, and particularly relates to a synthetic method for ceftazidime side chain acid ethyl ester. The method comprises the following steps: adding sodium nitrite and ethyl acetoacetate into water, adding acetic acid for a reaction, performing extraction, and collecting the organic phase; performing distillation on the collected organic phase under normal and reduced pressure to obtain an oxime compound, performing dehydration treatment on the oxime compound, adding an alcohol, a catalyst and chlorine gas, and performing a chlorination reaction to obtain a chloride; performing a reaction on methanol, thiourea, a phase transfer catalyst, a buffer salt solution and the chloride to obtain an ethyl 2-(2-aminothiazole-4-yl)-2-hydroxyiminoacetate solution; and performing distillation on the ethyl 2-(2-aminothiazole-4-yl)-2-hydroxyiminoacetate solution under reduced pressure to obtain ethyl 2-(2-aminothiazole-4-yl)-2-hydroxyiminoacetate solution and a buffer salt, adding tert-butyl 2-bromoisobutyrate, a condensation catalyst and a solvent, and performing a reaction to obtain the ceftazidime side chain acid ethyl ester. The method is moreefficient, simpler, and more environmentally friendly and has higher quality and yield than a previous processes, and is suitable for large-scale industrial production.

An alternative procedure for preparation of cefdinir

Cefdinir, a broad spectrum third-generation cephalosporin for oral administration, was prepared by the following synthetic pathway: synthesis of diphenylmethyl 7β-amino-3-vinyl-3-cephem-4-carboxylate hydrochloride from 7-aminocephalosporanic acid (7-ACA), preparation of sodium 2-(2-tritylaminothiazol-4-yl)-(Z)-2-(tritylhydroxyimino) acetate from ethyl acetoacetate, coupling of both intermediaries to obtain diphenylmethyl 7β-[2-(2-tritylaminothiazol-4-yl)-(Z)-2-tritylhydroxyimino-3- vinyl-3-cephem-4-carboxylate and final cleavage of trityl and diphenylmethyl protective groups. This procedure allows to obtain better yields of cefdinir and to avoid the use of diketene during the synthesis of this antibiotic by the previously reported method.

(6R,7R)-7-[(Z)-2-(2-Aminothiazol-4-yl)-2-(2-carboxyprop-2-oxyimino)acetamido]-3-(1-pyridiniummethyl)-ceph-3-em-4-carboxylate and salts thereof

Cephalosporin antibiotics of the general formula STR1 (wherein Ra and Rb, which may be the same or different, each represent a C1-4 alkyl group or Ra and Rb together with the carbon atom to which they are attached form a C3-7 cycloalkylidene group; and R4 represents hydrogen or a 3- or 4-carbamoyl group) exhibit broad spectrum antibiotic activity, the activity being unusually high against gram-negative organisms such as strains of Pseudomonas organisms. A particular antibiotic compound of formula (I) possessing excellent antibacterial activity against strains of Pseudomonas organisms, as well as other valuable therapeutic properties, is (6R,7R)-7-[(Z)-2-(2-aminothiazol-4-yl)-2-(2-carboxyprop-2-oxyimono) acetamido]-3-(1-pyridiniummethyl)-ceph-3-em-4 carboxylate. The invention also includes the non-toxic salts and non-toxic metabolically labile esters of compounds of formula (I). Also described are compositions containing the antibiotics of the invention and processes for the preparation of such antibiotics.

7-[2-(2-Aminothiazol-4-yl)-2-(syn)-methoxyiminoacetamido] cephalosporins

A 7-[2-(2-aminothiazol-4-yl)-2-(syn)-methoxyiminoacetamido] cephalosporin derivative of the formula; STR1 wherein R3 is hydrogen or a residue of a nucleophilic compound; R2 NH is an amino group which may optionally be protected, pharmaceutically acceptable salt or ester thereof, is found to have excellent anti-bacterial activity against a broad spectrum of bacteria inclusive of gram-negative bacteria such as Escherichia coli, Serratia marcescens, Proteus rettgeri, Enterobacter cloacae and Citrobacter freundii. Thus, this compound may be used for an antibacterial agent in therapeutical purposes.

Cephalosporanic acid derivatives

Novel syn isomers of 7-amino-thiazolyl-acetamido-3-acetoxymethyl-cephalosporanic acid derivatives of the formula STR1 wherein R1 is selected from the group consisting of --CN, --CONH2 and --COOR1 ', R1 ' is selected from the group consisting of alkyl of 1 to 3 carbon atoms, hydrogen, alkali metal, alkaline earth metal, ammonium, magnesium and a non-toxic, pharmaceutically acceptable organic amine, A is selected from the group consisting of hydrogen, alkali metal, alkaline earth metal, ammonium, magnesium and a non-toxic, pharmaceutically acceptable organic amine, R' and R" are individually selected from the group consisting of hydrogen and alkyl of 1 to 3 carbon atoms with the STR2 group in the syn position with the proviso that when R1 is --COOR1 ' and R1 ' is hydrogen, A is hydrogen and when R1 is --COOR1 ' and R1 ' is an alkali metal, alkaline earth metal, magnesium, ammonium or an organic amine, A is an alkali metal, alkaline earth metal, magnesium ammonium or an organic amine having antibiotic properties and novel intermediates and processes.

3-Acetoxymethyl-7-(iminoacetamido)-cephalosporanic acid derivatives

Compounds of the formula STR1 wherein R is hydrogen, R' is selected from the group consisting of alkenyl and alkynyl of 2 to 4 carbon atoms, A is selected from the group consisting of hydrogen, alkali metal and equivalents of an alkaline earth metal or magnesium and an organic amine base and the OR' group is in the syn position having antibiotic activity and process for their preparation.

3-Acetoxymethyl-7-(iminoacetamido)-cephalosporanic acid derivatives

Compounds of the formula STR1 wherein R is selected from the group consisting of hydrogen and groups easily removable by acid hydrolysis or hydrogenolysis, R' is selected from the group consisting of hydrogen, alkyl of 1 to 4 carbon atoms, alkenyl and alkynyl of 2 to 4 carbon atoms and groups easily removable by acid hydrolysis or hydrogenolysis, A is selected from the group consisting of hydrogen, alkali metal and equivalents of an alkaline earth metal or magnesium and an organic amine base with the proviso that when R' is a group easily removable by acid hydrolysis or hydrogenolysis, R is also and when R' is hydrogen, R also is hydrogen and the wavy line means the OR' group may be in either one of the two possible syn or anti positions having antibiotic activity and process for their preparation.