CA1063102A - 7-METHOXY-7-.alpha.-UREIDO(THIENYL AND FURYL) ACETAMIDOCEPHALOSPORINS - Google Patents

Abstract

Abstract Compounds of the formula wherein R is H, heterocyclic thio, pyridinium, carbamoyloxy or acetoxy; Y is H, Cl, Br, I, nitro or methylsulfonyl; Z is O or S;
and pharmaceutically acceptable salts and esters thereof are effective antibacterial agents.

Description

~310Z GG172/162 This invention relates to new 7-methoxy thienyl- and uryl-ureido-cephalosporins o the general formula Y - ~ CH-Il-NH ~ ~ ~ (V) O O N ~ C~I2R
C02~[

wherein R is H, heterocyclic thio, e.g. pyridyl-l-oxo-2-thio, 3-methyl-1,2,4-thiadiazolylthio, 1-methyl-tetrazolyl-5-thio,

2-methyl-1,3,4-thiadiazolyl~5-thio; pyridinium, carbamoyloxy or acetoxyS Y i9 hydrogen, Cl, Br, F, nitro or methylsulfonyl;
Z is O or S; and pharmaceutically acceptable carboxylate salts, lower alkyl esters, haloloweralkyl esters or acyloxymethyl esters thereof. The compounds of the present invention are effective antibacterial agents and are useful in the treatment of many gram negative and gram positive infections. These compounds are useful as disinfectants and also as nutritional supplements in animal feeds. The 7-methoxy group occupies the ~-configuration.
The compounds of the present invention may be prepared from a heterocyclic aldehyde o the formula Y ~ CHO (I) Z

.~

The heterocyclic aldehyde (I) is first converted to an :~
amino acid by known methods, for example, the well known Strecker amino acid synthesis, Ann 75, 27 (1850); 91, 349 (1854). This method involves the synthesis of a-amino acids ;~
by the simultaneous reaction of aldehydes with ammonia and hydrogen cyanide followed by hydrolysis of the resulting amino nitriles. As applied to the heterocyclic aldehyde I of the present invention the reaction is as follows:

Y~ CHO ~ L~--~1HC~ ~ Y~l HCO2H

In addition, various well known modifications of the Strecker synthesi~ may be employed. Fo.r example the Erlenmeyer modification:
. ~H2 1~ HCN IH2 Y~CHO + IIH3 -~ Y~3 CHOH 2 ) H20/H+ Y~CHCO2H

the Tiemann modification:

OH NH
Y ~ CHO + HCN ---~ Y~1HCN -~ ~ Y~ 1HCN

H20/H ., or OH ~

\ ~ INH2 ' Y~ CHC02H

.

, :: . . , ~: . ~ . .. .

10~3iOZ GG172/162 the Zel~nsky-Stadnikoff modification: ~
~H2 Y ~ CHO + NH4Cl -~ KCN ~ Y ~ CHCN

! H O/H+
lH2 Y~ HC02H
. ~.
and the Bucherer modification:

1) HCN ¦ (NH ~ CO
Y- ~ CHO ~ Y ~ CHCN 4 2 3> F ~=

CO-NH

Y ~ CHCO2H

The amino acid o the formula NH
2 (II) Y~CH-C02H

produced by any suitable method, for example, those described above, is then raacted with an alkali metal cyanate or an alkaline earth metal cyanate to form an a-ureido compound of the formula l (III) ~: -NH--C--y~CH~C02H

: _3_ ' ~ ' , .' ' ' ' ' . .
, .
. .

lQ~3102 GG172/162 This reaction takes place by treating an aqueous suspension of the ~-amino acid with the alkali or alkaline earth metal cyanate. Acidification with hydrochloric acid precipitates the ~-ureido acid in good yield. A solution of th~ a-ureido acid in an organic solvent containing a tri-(lower)alkyl amine is converted to a mixed carbonic or other anhydride by treating with an anhydride forming reagent, e.g., a lower alkyl chloro-formate, an aryl chloroformate, or an acyl halide, at reduced temperatures of from about 0C to about -20C. The reaction takes place in a solvent such as methylene chloride, chloroform, dioxane, dimethoxyethane, benzene, aqueous acetone or dlmethoxy-ethane, acetonitrile, or dimethylformamide.
Reaction at reduced temperatures o the mixed anhydride with a protected ester, e~g., benzhydryl, trichloroethyl, or tertiarybutyl, o a compound o the formula OCH
3f ~ : ::

20o// ~ H2R (VII) COOH

wherein R is as previously defined yields the compounds of the present invention after removal of the ester group. `
In general, a compound of formula V may be obtained by converting a compound of formula III to an activated ester or by reacting a compound of formula III with a carboxyl group activating agent, such as, or example, dicyclohexylcarbodiimide or bisimidazole carbonyl, and then coupling the activated form o the compound o formula III with a protected ester of the ,~ . :,-~ ' .

1~3~02 GGl72/162 compound of Formula VII. In some cases, as will be obvious to those skilled in the art, the carboxyl group may be activated by conversion to an acid halide, e,g., the chloride, or to an azide prior to coupling with a protected ester of the Formula VII compound. A more detail~d discussion of carboxyl activating groups may be obtained by reference to standard works on peptide synthesis, for example, Bodanszky et al., "Peptide Synthesis", Interscience, 1966.
Alternatively, the ~-amino acid (II) produced, for example by subjecting the heterocyclic aldehyde to the Strecker reaction or a modification thereof, may be used to acylate a protected ester of the Formula VII compound. The resulting ~-amino acid derivative of the Formula VII compound is then reacted with an alkali metal cyanate or an alkaline earth metal cyanate in the presence of water to form the compounds (V) of the present invention.
In the case of the products of Formula V wherein R is heterocyclic thio, the heterocyclic thio group may be inserted as the last step by displacement of the acetoxy group of the corresponding product of Formula V wherein R is acetoxy with the desired heterocyclic thio group by reaction with the desired mercaptoheterocycle according to conventional methods. The insertion can also be effected at an earlier stage by reacting a compound of Formula VII wherein R is acetoxy with the desired mercaptoheterocycle, see also Abraham and Newton (1950) Ciba Foundation Symposium, Amino Acids, Peptides, Antimetabolic Activity, p. 205; U. S. Patent 3,225,038; and Belgian patents 641 r 338 and 652,148.

, , ~.- ~ ., ~L~63~0Z

The a-amino acid (II) or the ~-ureido acid (III) obtained occurs as a racemate of D and L optical isomers. It is gen-erally possible to resolve these compounds by using optically pure bases (or acids) using methods known to the art, for example, as described by L. Velluz, "Substances Naturelle de Synthesese," 9, pp. 119-174 (1954), or E.L. Eliel, "Stereo-chemistry of Carbon Compounds," Chapter 4, McGraw-Hill Book Co., N.Y. (1962). The resulting pure D or L acid may then be coupled to a protected ester of the Formula VII moiety. ; ~ ?
10 Generally the coupling of the D form leads to the more active ~ ;
product.
When preparing compounds of the present invention according to the reaction sequence wherein a protected ester of the com-pound of Formula VII i9 acylated with an a-amino aaid of Formula II, it may be desirable to protect the a-amino group during the acylation reaction by means of an amino protecting group. Such amino protecting groups are well known in the art and are described, for example, by Bodanszky et al., "Peptide Synthesis," supra. ~
Specific examples of methods for acylating the cephalo- ~ ;
sporin of Formula VII are similar to those described for the acylation of 7-ACA or 7-ADCA, for example, in Netherlands Patent 6,812,382, Belgian Patent 675,298, as well as in the ~;
following articles:
Spencer et al., J. Med. Chem., 9, 746 tl966);
Ryan et al., ibid, 1~, 310 tl969).
A general reaction scheme for preparing compounds of the . ~;, .. .
present invention is shown below wherein for ease of represen ~-tation A is the residue of the cephalosporin moiety of Formula VII.

- . .::. . . . . .

~0~3~z GGl72/162 1) HCN ~ 1 2 HO 3) H2O/H y_ ~ CH-cO2H

(I) / (II) / ~alkali or alkaline earth cyanate/H20 / \ ' 1l' ~ / NHC-NH (III) Y~ CH-C02H

Y- ~ ~ CH-C-A (VI) ~:
~Z O 1) tri-(lower)alkyl \ 2) anhydride forming \ reagent :~

~ / NH--C-NH2 \ Y ~ CH-C-OCR (IV) : :
alkali or \
alkaline earth \ . .
cyanate/H20 \ ., AH '~

\ ~ NH-Il-NH
y ~ CH-~-A (V) ..

7- ? ' : ' . . ' ' ' ' ' ' ' ' '', ,. ' ~ ' , ` ; : .

1~3~

The carboxylate salts of the compounds (V) of the present invention are formed by reacting the carbo~yl group of the ceph-alosporanic acid moiety with a salt formin~ ion, e.g., an alkali metal such as sodium or potassium, or an a]Lkaline earth metal such as magnesium or calcium, or a metal of group IIIA such as aluminum, or the radical of an organic base such as dibenzyl-amine, N,N-dibenzylethylenediamine or other organic bases known to form salts with cephalosporanic acids.
The lower alkyl esters may be obtained by esterifying the carboxyl group of the cephalosporanic acid moiety with a str~aight or branched chain lower alkyl halide of from 1 to 3 carbon atoms, e.g., methyl chloride, ethyl bromide and the like, or with a diazoalkane of from 1 to 3 carbon atoms, e.g., diazo-methane, diazoethane, and the like. The resulting ester group is then formed by a radical such as methyl, ethyl, propyl, or isopropyl.
The acyloxymethyl esters may be obtained according to known methods, for example, a method adapted from that of `
Daehne et al., J. Med. Chem~ 13, 607 (1970), by reacting the carboxyl group or a metal ~alt thereof of the cephalosporanic acid moiety with a halide of the formula O . ~' Il ~.. ..
X-CH2-O-C-R' ! .
wherein R' may be lower alkyl of up to 5 carbon atoms, phenyl, -benzyl or phenethyl, and X is chlorine or bromine. Thus, suit~
able compounds include acetoxymethyl chloride, propionyloxy~
methyl chloride, butyryloxymethy1 chloride, pivaloyloxymethyl chloride, valeryloxymethyl chloride, benzoyloxymethyl chloride, or phenacetoxymethyl chloride, and the like.

. ~ . . .
.

~31~2 GG172/162 It will be appreciated that certain of the compounds of this invention exist in various states of solvation as well as in different optically active forms. The various forms as well as their mixtures are within the scope of this invention.
The compounds of this invention have a broad spectrum of antibacterial activity against both gram positive and gram negative organisms such as Staph~lococcus aureus, Salmonella schottmuelleri, Proteus vul~aris~ Escherichia coli and Streptococcus pyogenes. They may be used an antibacterial agents in a prophylactic manner, e.g., in cleaning or dis-infecting compositions, or otherwise to combat infections due to organisms such as those named above, and in general may be utilized in a manner similar to cephalosporin C, cephalothin and other cephalosporins. For example, a compound of formula V
or a physiologically acceptable salt or ester thereof may be used in various animal species in an amount of about 1 to 200 mg./kg. daily, orally or parenterally, in single or two to four ~, divided doses to treat infections of bacterial origin.
Up to about 600 mg of a compound of formula I or a pharmaceutically acceptable salt or ester thereof may be incor-porated in an oral dosage form such as tablets, capsules or eli~irs or in an injectable form in a sterile aqueous vehicle prepared according to conventional pharmaceutical practice.
In cleaning or disinfecting compositions, e.g., in barns or dairy equipment, a concentration of about 0.01 to 1~ by weight of such compounds admixed with, suspended or dissolved in conventional inert dry or aqueous carriers for application by washing or spraying may be used.
They are also useful as nutritional supplem~nts in animal feeds.

.:

:~ :

~63iOZ ~ .
The compounds of the present invention in the described dosages may be administered orally; however r other routes such as intraperitoneally, subcutaneously, intramuscularly or intra-venously may be employed.
The active compounds of the present invention are orally administered, for example, with an inert diluent or with an assimilable edible carrier, or they may be enclosed in hard or soft gelatin capsules, or they may be compressed into tablets, or they may be incorporate~ directly with the food of the diet.
For oral therapeutic administration, the active compounds Of n this invention may be incorporated with excipients and used in the form of tablets, troches r capsules, elixirs, suspensions, syrups, waers, chewing gum, and the like. The amount of active compound in such therapeutically useful compositions or pre- ;
parations is such that a suitable dosage will be obtained.
The tablets, troches, pills, capsules and the like may -~
also contain the following: a binder such as gum tragacanth, acacia, corn starch or gelatin; an excipient such as dicalcium ;
phosphate; a disintegrating agent such as corn starch, potato starch, alginic acid and the like; a lubricant such as magnesium `
stearate; and a sweetening agent such as sucrose, lactose or saccharin may be added or a flavoring agent such as peppermint, oil of wintergreen, or cherry flavoring. When the dosage unit form is a capsule, it may contain in addition to materials of the above type a liquid carrier such as a fatty oil. Various other materials may be present as coatings or to otherwise modify the physical form of the dosage unit, for instance, tablets, pills or capsules may be coated with shellac, sugar, or both. A syrup or elixir may contain the active compounds, sucrose as a sweetening agent, methyl and propyl parabens as . , ~ . . . . .

1~3~0Z
preservatives, a dye and a flavoring such as cherry or orange flavor. Of course, any material used in preparing any dosage unit form should be pharmaceutically pure and substantially non-toxic in the amounts employed.
In the compound of Formula VII wherein R is as previously defined OCH
H2~ ~
~ ~ C 2 I `' COO~ , ~. ...

the 7-methoxy group has the a-configuration. :~

'.

-. , ~ ; . .

1~6310Z GG172/162 The following exampl~s illustrate the present invention without, however, limiting the same thereto.
Example 1 7-[2-Ureido-2-(2-thien~l)acetamidol-7-methox~cephalosporanic acid Method A
2-Thiophene carboxaldehyde is reacted with ammonium cyanide prepared in situ from ammonium chloride and sodium cyanide. The resulting amino nitrile is hydrolyzed to yield thienyl-2-(2-amino)acetic acid. A suspension of the latter compound (0.10 ~, moles in 150 ml of water is treated with 8.1 g of potassium cyanate. The resulting mixture is heated to about 80C to gi~e a clear solution which is then allowed to stand at roorn temperature for about 24 hours, Acidification to pH 3.5 with hydrochloric acid preclpitates the a-ureido compound~ A solution containing 0.10 moles of the a-ureido acid in 100 ml of acetone containing 10.1 g. of triethylamine at a temperature of from about 0C ~o about -20C is converted to a mixed carbonic anhydride by treating with 10.~ g of ethyl chloroformate for about 30 minutes. A cold (about -10C) solution of 0~10 mole of 7-amino-7-methoxy-cephalosporanic acid, benzhydryl ester [Cama et al., J.A.C.S., 94, 1408 (1972)] in 400 ml o 1:1 acetone containing 10.1 g of triethylamine is added to the solution of mixed anhydride and the reaction mixture stirred vigorou~ly at about 0C for approximately 30-45 minutes. The volume of the solution is reduced by evaporating the bulk of the acetone at reduced pressure at room temperature or below.
One liter of ethyl acetate is added and the solution washed with 2 X 200 ml of ice cold 5~ aqueous sodium bicarbonate 100 ml of water, 2 X 200 ml of 0.5 molar hydrochloric acid, and 100 ml again of water. The ethyl acetate solution is dried :: ~ ' '::,: .

10~3~0Z GG172/162 (Na2SO4) and evaporated to deposit the benzhydryl ester of the title compound.
The free acid is obtained by dissolving the ester (1 g) and anisole (500 mg) in 20 ml of ice cold trifluoroacetic acid and keeping it at 0-5C for 30 minutes. The acid solvent is evaporated at reduced pressure. The residue is treated with 50 ml of water and the pH adjusted to 7.5 to dissolve the ;
product. The solution is washed with ethyl acetate.
(Lyophilization of the aqueous solution deposits the sodium ~;
10 salt of the title compound). The aqueous layer is acidified "
to precipitate the title compound.
Method B
A solution containing 0.1 mole of 2-(p-methoxybenzyloxy-carbonylamino)-2-thiophene acetic acid in 100 ml of acetone containing 10.1 g o triethylamine at a temperature of -10C
is converted to a mixed carbonic anhydride by treating with 10.8 g of ethyl chloroformate for about 30 minutes. ~ cold (about -10C.) solution of 0.1 mole of 7-amino-7-meth~xy cephalosporanic acid benzhydryl ester in 400 ml of 1:1 acetone containing 10.1 g of triethylamine is added to the solution of mixed anhydride and the reaction mixture stirred vigorously at about 0C for approximately 30-45 minutes. The volume of the solution is reduced by evaporating the bulk of the acetone at reduced pressure at room temperature.
One liter of ethyl acetate is added and the solution -washed with 2 X 200 ml of ice cold 5% aqueous sodium bicarbonate, 100 ml of water, 2 X 200 ml of 0.5 molar hydrochloric acid, and 100 ml again of water. The ethyl acetate solution is dried (Na2SO4) and evaporated to yield the 7-[2~p-methoxybenzyloxy-, ~, ' carbonylamino)-2-thiophene acetamido]-7-methoxy cephalosporanic acid benzhydryl ester.
The free amino acid i~ obtained by dissolving the ester ;~
(11 g.) and anisole (30 ml) in 150 ml of ice cold trifluoro- ;
acetic acid and keeping it at -5C for 20 minutes. The acid solvent is evaporated at reduced pressure. The residue is triturated with ether and dried .
The 7-thienylglycyl-7-methoxy-cephalosporanic acid (5 g.) ~
and potassium cyanate (1.4 g.) are dissolved in water (35 ml.). ~ - -The mixture is stirred for three hours, filtered and the filtrate adjusted to pH 1.5 to precipitate the compound of the title.
Ex mple 2 7-[7-Ureido-2-(2-thienyl)aaetamido]-7-methoxy-3-desaaetoxy-cephalosporanic acid Following the procedure of example 1 but substituting ~
0.1 mole of 7-amino-7-methoxy-3-desacetoxycephalosporanic acid ~ ;
benzhydryl ester for 7-amino-7-methoxycephalosporanic acid benzhydryl ester, the title compound is obtained.
, Example 3 Pivaloyloxymethyl ester of 7-[2-ureido-2-(2-thienyl)-acetamldo]-7-methoxy-3-desacetoxy cephalosporanic acid Chloromethylpivalate (20 mmole) is combined with 10 mmole of the product of example 2, 0.4 ml o a 5% aqueous sodium ;
iodide solution, and 170 ml of acetone. Triethyl amine, 2.0 gm.
(20 mmole), is added and the mixture stirred for 10 hours, then refluxed for one hour. The reaction mixture is cooled and con-centrated ln vacuoO The residue is partitioned between ethyl acetate, and 5% aqueous sodium bicarbonate. The organic layer is dried over sodium sulfa~e and evaporated to give the crude ~33L~2 product which is obtained as a powder upon trituration wi~h ether.
Example 4 Pivaloyloxymethyl ester of 7-[?-ureido-2-(2-thienyl)-acetamido~-7~methox ce halos oranic acid Y P P
Following the procedure of example 3 but substituting 10 mmole of the product of example 1 for the produat of example

3, the title compound is obtained.
Exam~le 5 7-[2~Ureido-2-(2-thienyl)acetamido]-7-methoxy-3-desacetoxy cephalosporanic acid, methyl ester A 0.1 molar solution of the product of example 2 in dimethoxyethane i9 treated with an excess o ethereal diazo- ,~
methane. Evaporation o~ the solvent at reduced pressure deposits the title compound.
Example 6 Aceto~methyl ester of 7-[2-ureido-2-(2-thienyl)acetamido]-7-methoxy~cephalosporanic acid ,: . .
Following the procedure of example 4 but substituting chloromethylacetate for chloromethylpivalate, the title compound is obtained.
Example 7 7-~2-Ureido-2~(2-thienyl)acetamido~-7-methoxycephalosporanic acid, potassium salt .
One millimole of the product of example 1 is dissolved in 10 ml of a 0.01 N aqueous KOH solution. Lyophilization of the solution yields the title compound.

... .
, :

i~363~0Z
Example 8 7-[2-Ureido-2-(2~thienyl)acetamido]~7-methoxy-3-desacetoxy cephalosporanic acid, calcium salt . ~
One millimole o the product of example 2 is dissolved in 10 ml of a 0.05 N aqueous Ca(OH~2 solution. Lyophilization ~ ~
of the solution yields the title compound. - i Example 9 :. :
7-[2~Ureido-2-(2-thienyl)acetamido]-7-methoxy-3-[2-(5-methyl-1,3,4~thiadiazolyl~thiomethyl-~3-cephem-4-carboxylic acid A solution (0.026 mole) of the product of example 1, NaHCO3 (2.1 g) and 3.8 g 2-mercapto-1,3,4-thiadiazole in 200 ml of pH -6.4 phosphate buffer is stirred for 5.5 hours at 60C. The reaction is cooled to room temperature, acidified to pH 3 and extracted with ethyl acetate. The ethyl acetate layer is worked with saturated NaCl solution, dried (Na2SO4), and evaporated at reduced pressure to deposit the product.
Exam~le 10 7-[2-Ureido-2-(2-thienyl)acetamido~-7-methoxyce~haloSporaniC
acid, N,N'-dibenzylethylenediamine salt A solution of 0.010 mole of the product of example 1 in 25 ml of ethanol is added to a solution of 1.20 g of N,N-dibenzylethylenediamine in 25 ml of ethanol at room temperature.
- After 15 minutes stirring the solvent is evaporated to deposit the title compound. ~-Example 11 7-[2-Ureido-2-(2-th:ienyl)acetamido]-7-methoxycephalosporanic acid 2-Thiophene carboxaldehyde is reacted with ammonium cyanide preparad ln situ from ammonium chloride and sodium cyanideO The resulting amino nitrile is hydrolyzed to yield thienyl-2-(2-; : . ~ . - ~ .
.
.: , .i . . .. ..

1~63~ \2 amino)acetic acid. A suspension of the latter compound (0.10 moles) in 150 ml of water is treated with 8.1 g of potassium cyanate. The resulting mixture is heated to about 80~C to give a clear solution which is then allowed to stand at room tem-perature for about 24 hours. Acidification to pH 3.5 with hydrochloric acid precipitates the ~-ureido compound. A
solution containing 0.10 mol~s of the ~-ureido acid in 100 ml.
of acetone containing 10.1 g of triethylamine at a temperature of from about 0C to about -20C is converted to a mixed carbonic anhydride by treating with 10.8 g of ethyl chloro-formate for about 30 minutes. A cold (about -10C.) solution ;
of 0.10 mole of 7-amino-7-methoxy-trichloroethyl ester (prepared as described in Netherlands Patent 7r204,982) in 400 ml. of 1:1 acetone containing 10~1 g of triethylamine is added to the solution of mixed anhydride and the reaction mixture stirred vigorously at about 0C for approximately ~;
30-45 minutes. The volume of the solution is reduced by evaporating the bulk of the acetone at reduced pressure at room temperature or below.
One liter of ethyl acetate is added and the solution washed with 2 X 200 ml. of ice cold 5% a~ueous sodium bicar-bonate, 100 ml of water, 2 X 200 ml of 0.5 molar hydrochloric acid, and 100 ml again of water. The ethyl acetate solution -~
dried (Na2SO4) and evaporated to deposit the trichloroethyl ;
ester of the title compound. ;
The free acid is obtained by dissolving the ester (1 g.) in 30 ml. of cold 90% acetic acid and adding 1 g of zinc to :,. .
the vigorously stirred solution. After one hour the acid ~ ~
solvent is evaporated at reduced pressure. The residue is ~ ~ -30 treated with 50 ml of water and the pH adjusted to 7.5 to `-.: .
;. ,. : : . . ~

~G172/162 ~C~63~0Z ~
dissolve the product. The solution is washed with ethyl acetate. (Lyophilization of the aqueous solution deposits the sodium salt of the title compound). The aqueous layer ;~
is acidified to precipitate the title compound.
Example 12 7-~2-Ureido-2 (2-thienyl)acetamidol-7-methoxy-3-carbamoyloxy-.
methyl-~3-cephem-4-carboxylic acid 2-Thiophene carboxaldehyde is reacted with ammonium cyanide prepared in situ from ammonium chloride and sodium cyanide. The resulting amino nitrile is hydrolyzed to yield thienyl-2-~2-amino)acetic acid. A suspension of the latter compound (0.10 moles) in 150 ml of water is treated with 8.1 g.
of potassium c~anate. The resulting mixture is heated to about 80C. to give a clear solution which is then allowed to stand at room temperature for about 24 hours. Acidification to pH 3.5 with hydrochloric acid precipitates the ~-ureido compound. A solution containing 0.10 moles of the ~-ureido acid in 100 ml of a~etone containing 10.1 g of triethylamine at a temperature of from about 0C to about -20C is converted ~`
to a mixed carbonic anhydride by treating with 10.8 g of ethyl chloroformate for about ~0 minutes. A cold (about -10C) solution of 0.10 mole of 7-amino-7-methoxy-3-carbamoyloxymethyl-~3-cephemr4-carboxylic acid, benzhydryl ester in 400 ml of 1:1 , acetone containing 10.1 g of triethylamina is added to the solution of mixed anhydride and the reaction mi~ture stirred vigorously at about 0C for approximately 30-45 minutes. The volume of the solution is reduced by evaporating the bulk of the aceton~ at reduced pressure at room temperature or below.
One liter of ethyl aceta~e is added and the solution 30 washed with 2 X 200 ml of ice cold 5% aqueous sodium bicarbonate, . . , :

~3~(~Z
100 ml of water, 2 X 200 ml of 0.5 molar hydrochloric acid, and 100 ml again of water. The ethyl acetate solution is dried (Na2SO4) and evaporated to deposit the benzhydryl ester of the title compound.
The free acid is obtained by dissolving the ester (1 g) and anisole (500 mg~ in 20 ml of ice cold tri~luoroacetic acid and keeping it at 0-5C for 30 minutes. The acid solvent is evaporated at reduced pressure. The residue is treated with 50 ml of water and the pH adjusted to 7.5 to dissolve the product. The solution is washed with ethyl acetate. (Lyophilization of the aqueous solution deposits the sodium salt of the title compound). The aqueous layer is acidified to precipitate the title compound.
Examples 13-15 Following the procedure of example 9 but s~bstituting for 2-mercapto-1,3,4-thiadiazole, the heterocyclicthio compound listed below in column I, there is obtained respectively the ~inal compound of column II.
I II
13. Pyridinyl-l-oxo-2-thiol 7-E2-Ureido-2-(2-thienyl)-acetamido]-7-methoxy-3-~2-(l-oxopyridinyl)thiomethyl]-~3-cephem-4-carboxylic acid.
14. 3-methyl-1,2,4-thiadia- 7-[2-Ureido-2-(2-thienyl)-zolyl-5-thiol acetamidol-7-methoxy-3-[5-(3-methyl-1,2,4-thiadiazolyl)-thiomethyl]-~3-cephem-4-car-boxylic acid 15. 1-methyltetrazolyl-5- 7-[2-Ureido-2-(2-thienyl)-thiol acetamido]-7-methoxy-3-(5-(1- ~-methyltetrazolyl)-thiomethyl]-~3-cephem-4-carboxylic acid : ' ' '' .'' ' ~0~3102 GG172/162 Example 16 7-[2-Ureido-2-(2~thienyl)acetam_do-7-methoxy-3-[1-pyridinium-methyl] ~3-cephem-4-carboxylic acid .
.
A solution of 0.046 mole of the product of example 1, -sodium salt, 10 g of potassium thiocyanate and 10 ml of pyridine ~;
in 50 ml of water is adjusted to pH 6.5 with 85% phosphoric acid and warmed to 60 for 6 hours~ The solution is cooled to room temperature and extracted with a 25% solution of Amberlite LA-l (acetate form~ in methyl isobutylketone (6 X 100 ml). After ;
standing overnight at 0 to 5C the title compound separates.
Example 17 ':
7-[2-Ureido-2-(2-thienyl)acetamido-7-methoxy-3-(5-(1-methyl-tetrazolyl)thiomethyl]-~3-cephem-4-carboxylic acid Following the procedure of example 1, but substituting for 7-amino-7-methoxy-cephalosporanic benzhydryl ester, the 7-amino-7-methoxy-3-[5(1-methyltetrazolyl)-thiomethyl]-~3-cephem-4-diphenylmethyl carboxylate (Belgium Patent 817836), the title compound (m.p. 170-175) is obtained.
Example_18 7-[2-Ureido-2-(2-furyl)acetamido]-7-methox~cephalosporanic acid Furfural is reacted with ammonium cyanide prepared in situ from ammonium chloride and sodium cyanide. The resulting amino nitrile is hydrolyzed to yield furyl-2-(2-amino)acetic acid. A
suspension of the latter compound (0.10 moles) in 150 ml of water is treated with 8.1 g of potassium cyanate. The resulting mix-ture is heated to about 80C to give a clear solution which is then allowed to stand at room temperature for about 24 hours.

Acidification to pH 3,5 with hydrochloric acid precipitates the ~-ureido compound. A solution containing 0.10 moles of the ~-ureido acid in 100 ml of acetone containing 10.1 g of triethyl-.

. . . .. - . .. . ..

:

i31~f~
amine at a temperatuxe of from about 0C to about -20C is converted -to a mixed carbonic anhydride by treating with 10.8 g of ethyl chloroformate for about 30 minutes. A cold tabout -10C) solution of 0.10 mole of 7-amino-7-methoxy-cephalosporanic acid, benzhydryl ester [Cama et al., J.A.C.S., 94, 1408 (1972)] in 400 ml of 1:1 acetone-wa'cer containing 10.1 g of triethylamine is added to the solution of mixed anhydride and the reaction mixture stirred vigorously at about 0C for approximately 30-45 minutes. The volume of the solution is reduced by evaporating the bulk of the acetone at reduced pressure at room temperature or below.
One liter o-f ethyl acetate is added and the solution washed with 2 X 200 ml of ice cold 5% aqueous sodium bicarbonate, 100 ml of water, 2 X 200 ml of 0.5 molar hydrochloric acid, and 100 ml again of water. The ethyl acetate solution is dried (Na2SO4) and evaporated to deposit the benzhydryl ester vf the title compound.
The free acid is obtained by dissolving the ester ~l g) and anisole (500 mg) in 20 ml of ice cold trifluoroacetic acid and keeping it at 0-5C for 30 minutes. The acid solvent is evaporated at reduced pressure. The residue is treated with 50 ml o water and the pH adjusted to 7.5 to dissolve the product. The solution is washed with ethyl acetate. (Lyophili-zation of the aqueous solution deposits the sodium salt of the title compound). The aqueous layer is acidified to precipitate the title compound.

. .

~... .
... . . . . . . . . . . . .
,, ~

10~3~Z GG172/162 Example 19 7-[2-Ureido-2-(2-furyl~acetamido~-7-methoxy-3-desacetoxy cephalosporanic acid Following the procedure of example 18 but substituting 0.1 mole of 7-amino-7-methoxy-3-desacetoxycephalosporanic acid for 7-amino-7-methoxycephalosporanic acid, the title compound is obtained.
Example 20 Pivaloyloxymethyl ester of 7-[2-ureido-2-(2-furyl)acetamido]-7-methoxy-3-desacetoxy cephalosporanic acid Chloromethylpivalate (20 mmole) is combined with 10 mmole of the product of example 19, 0.4 ml of a 5~ aqueous sodium iodide solution, and 170 ml of acetone. Triethylamine, 2.0 gm (20 mmole), is added and the mixture stirred for 10 hours, then refluxed for one hour. The reaction mixture is cooled and con-centrated ln vacuo. The residue is partitioned between ethyl acetate, and 5% aqueous sodium bicarbonate. The organic layer is dried over sodium sulfate and evaporated to give the crude product which is obtained as a powder upon trituration with ether.
Exa ple 21 Pivaloyloxymethyl ester of 7-[2-ureido-2-(2-furyl)acetamido-?-methoxy cephalosporanic acid Following the procedure of example 20 but substituting 10 mmole of the product of example 18 for the product of example 19, the title compound is obtained.
Example 22 - 7-[2-Ureido-2-(2-fur~l?acetamido~-7-methoxy-3-desacetoxy cephalosporanic acid, methyl ester A 0.1 molar solution of the product of example 19 in di--~0 methoxyethane is treated with an excess of ethereal diazomethane.

,.~ , . . .

,, ; . . .

63~0Z
Evaporation of the solvent at reduced pressure deposits the title compound.
Example 23 Acetoxymethyl eA~e r ~ 7 ~Z ~rèido-2-(2-furyl)acetamido]-7-methox ce halos oranic acid _ ~ P P
Following the procedure of example 21 but substituting chloromethylacetate for chloromethylpivalate, the title compound is obtained.

, :
7-[2-Ureido-2-(2-furyl)acetamido]-7-methoxycephalosporan:ic acid, potassium salt One millimole of the product of example 18 i9 dissolved in `~
10 ml of a 0.01 N aqueous KOH solution. Lyophilization of the solution yields the title compound.
Example 25 7-[2-Ureido-2-(2-furyl)acetamido]-7-methoxy-3-desacetoxy cephalosporanic acld, calcium salt One millimole of the product of example 19 is dissolved in 10 ml of a 0.05 N aqueous Ca(OH)2 solution. Lyophilization of the solution yields the title compound.
Example 26-33 :
Following the procedure of example 18 but substituting for furfural an equivalent amount of the aldehyde indicated in column I, there is obtained the 7-methoxy cephalosporanic acid indicated in column II.
I II
26. 5-chloro-2-furaldehyde 7-[2~ureido-2-(5 chloro-2-furyl)acetamido]-7-methoxy-cephalosporanic acid : , . . . .
Jt. I.1,, ' ~ . ' GG172/162 ~ ~
1CÇ~311~2 ~ ~

27, 5-iodo-2-furaldehyde 7-[2-ureido-2-(5-iodo-2- -furyl)acetamido]-7-methoxy-cephalosporanic acid 28. 5-nitro-2-furaldehyde 7-[2-ureido-2-~5-nitro-2- ~-furyl)acetamido]-7-methoxy-cephalosporanic acid 29. 5-phenyl-2-furaldehyde 7-[2-ureido-2-(5-phenyl-2-furyl)acetamido]-7-methoxy-cephalosporanic acid 30. 3-furaldehyde 7-[2-ureido-2-(3-furyl)-acetamido]-7-methoxy-cephalosporanlc acid 31, 5-bromo-2-furaldehyde 7-12-ureido-2-(5-bromo-2-furyl)acetamido]-7-methoxy-cephalosporanic acid 32. 5-methylsulfonyl-2- 7-[2-ureido-2-(5-methylsulfonyl-furaldehyde 2-furyl)acetamido]-7-methoxy-cephalosporanic acid 33. 4-chloro-3-furaldehyde 7-[2-ureido-(4-chloro-3-furyl)acetamido]-7-methoxy-3-desacetoxy-cephalosporanic acid 7-~2-Ureido-2-(2-furyl)acetamido]-7-methoxycephalosporanic acid, N,N'-dibenzylethylenediamine salt_ :
A solution of 0.010 mole of the product of example 18 in 25 ml of ethanol is added to a solution of 1.20 g of N,N'-di- ~ ;
benzylethy~nediamine in 25 ml of ethanol at room temperature.
Ater 15 minutes stirring the solvent is evaporated to deposit the title compound.

: ~

31~3Z

~ le 35 7-[2-Ureido-2-(2-furyl)acetamido]-7-methoxy-3-[2-(5-methyl-1,3,4-thiadiazolyl-thiomethyl~-~3-cephem-4~-carbox~lic acid A solution (0.026 mole) of the product of example 18 NaHCO3 (2.1 g) and 3.8 g 2-mercapto-1,3,4-thiadiazole in 200 ml of p~ 6.4 phosphate buffer is stirred for 5.5 hours at 60C. The reaction is cooled to room temperature, acidiied to pH 3 and extracted with ethyl acetate. The ethyl acetate layer is worked with saturated NaCl solution, dried (Na~SO4), 0 and evaporated at reduced pressure to deposit the product.
Exam~le 36 7-[2-Ureldo-2-(2-furyl)acetamido]-7-methoxy-3-carbamoyloxy-methyl-~3-cephem-4-carboxylic acid Furfural is reacted with ammonium cyanide prepared in situ from ammonium chloride and sodium cyanide. The resulting amino nitrile is hydrolyzed to yield thienyl-2-(2-amino)acetic acid.
A suspension of the latter compound (0.10 moles) in 150 ml of water is treated with 8.1 g of potassium cyanate. The resulting mixture is heated to about 80C to give a clear solution which is then allowed to stand at room temperature for about 24 hours.
Acidification to pH 3.5 with hydrochloric acid precipitates the a ureido compound. A solution containing 0.10 moles o~ the ~-ureido acid in 100 ml of acetone containing 10.1 g of triethyl-amine at a temperature of from about 0C to about -20C is converted to a mixed carbonic anhydride by treating with 10.8 g of ethyl chloroformate for about 30 minutes. A co~d (about -10C) solution of 0.10 mole of 7-amino-7-methoxy-3~carbamoyl-oxymethyl-~3-cephem-4-carboxylic acid, benzhydryl ester in 400 ml of 1:1 acetone containing 10.1 g of triethylamine is added to the solution of mixed anhydride and the reaction 10~3102 GG172/162 mixture stirred vigorously at about 0C for approximately 30-45 minutes. The volume of the solution is reduced by evaporating the bulk of the acetone at reduced pressure at room temperature or below.
One liter of ethyl acetate is added and the solution washed with 2 X 200 ml of ice cold 5~ aqueous sodium bicarbonate, 100 ml of water, 2 X 200 ml of 0.5 molar hydrochloric acid, and 100 ml again of water. The ethyl acetate solution is dried (Na2SO4) and evaporated to deposit the benzhydryl ester of the title compound.
The free acid is obtained by dissolving the ester (1 g) and anisole (500 mg) in 20 ml of ice cold tri1uoroacetic acid and keeping it at 0-5C for 30 minute~, The acid solvent is evaporated at reduced pressure. The residue is treated with 50 ml o water and the pH adjusted to 7.5 to dissolve the product. The solution is washed with ethyl acetate. (Lyophili~
zation of the aqueous solution deposits the sodium salt of the ~itle compound). The aqueous layer is acidified to precipitate the title compound.
Examples 37-39 Following the procedures o example 35 but substituting for 2-mercapto-1,3,4-thiadiazole, the heterocyclicthio compound listed below in column I, there is obtained respectively the final compound of column II.
I II
37. Pyridinyl-l oxo-2-thiol 7-[2-Ureido-2-(2-furyl)-acetamido]-7-methoxy-3-[2-(l-oxopyridinyl)thiomethyl]-~3-cephem-4-carboxylic acid ~ ~ GG172/162 38. 3-methyl-1,2,4-thia- 7-12-Ureido-2-(2-furyl)~
diazolyl-5-thiol acetamido]-7-methoxy-3-[5-(3-,, . ;, methyl-1,2,4-thiadiazolyl)-thiomethyl~Q3-cephem~4-carboxylic acid 39, l-methyltetrazolyl- 7-[2-Ureido-2-(2-furyl)-5-thiol acetamido]-7-methoxy-3-(5-(1-methyltetrazolyl)thiomethyl-Q3-cephem-4-carboxylic acid Example 40 7-[2~Ureido-2-(2-furyl)acetamido-7-methoxy-3-[1-~yridlnium-methyl]-Q3-cephem-4-carboxylic acid A solution of 0.046 mole o~ the product of example 18 sodium salt, 10 g of potassium thiocyanate and 10 ml of pyridine in 50 ml of water is adjusted to pH 6.5 with 85~ ~
phosphoric acid and warmed to 60 for 6 hours. The solution ~ ~ ;
is cooled to room temperature and extracted with a 25% solution of Amberlite LA-l (acetate form) in methyl isobutylketone ;
(6 X 100 ml). After standing overnight at 0 to 5C the title compound separates. ' .

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Claims (2)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A process for preparing a compound of the formula and pharmaceutically acceptable salts, thereof, characterized by (a) reacting a compound of the formula with a compound of the formula wherein R is acetoxy or 1-methyltetrazol-5-ylthio, and where R is acetoxy, further reacting the product thereof with 1-methyltetrazol-5-ylthiol, or (b) reacting a compound of the formula with a compound of the formula wherein R is acetoxy or 1-methyltetrazol-5-ylthio, and further reacting the product thereof with an alkali metal cyanate or alkaline earth metal cyanate, and where R of said product is acetoxy, further reacting said product with 1-methyl-tetrazol-5-ylthiol.

2. A compound of the formula and pharmaceutically acceptable salts thereof, whenever prepared by the process of claim 1.