CA1041515A - Preparation of 6,7-dialkoxy-4-oxy-quinoline- 3 carboxylic acid ester compounds - Google Patents
Preparation of 6,7-dialkoxy-4-oxy-quinoline- 3 carboxylic acid ester compoundsInfo
- Publication number
- CA1041515A CA1041515A CA207,853A CA207853A CA1041515A CA 1041515 A CA1041515 A CA 1041515A CA 207853 A CA207853 A CA 207853A CA 1041515 A CA1041515 A CA 1041515A
- Authority
- CA
- Canada
- Prior art keywords
- carboxylic acid
- process according
- ethoxy
- oxyquinoline
- quinoline
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D215/00—Heterocyclic compounds containing quinoline or hydrogenated quinoline ring systems
- C07D215/02—Heterocyclic compounds containing quinoline or hydrogenated quinoline ring systems having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen atoms or carbon atoms directly attached to the ring nitrogen atom
- C07D215/16—Heterocyclic compounds containing quinoline or hydrogenated quinoline ring systems having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen atoms or carbon atoms directly attached to the ring nitrogen atom with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D215/48—Carbon atoms having three bonds to hetero atoms with at the most one bond to halogen
- C07D215/54—Carbon atoms having three bonds to hetero atoms with at the most one bond to halogen attached in position 3
- C07D215/56—Carbon atoms having three bonds to hetero atoms with at the most one bond to halogen attached in position 3 with oxygen atoms in position 4
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
- Quinoline Compounds (AREA)
- Plural Heterocyclic Compounds (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
This invention relates to a process for the preparation of 6,7-dialkoxy-4-oxyquinoline-3-carboxyl acid-esters of the general formula:
(I) wherein R1 stands for a C1-4 alkyl group, R2 stands for an alkenyl or alkyl group, containing 3-12 carbon atoms, and R3 stands for a C1-4 alkyl or phenyl-C1-4 alkyl group, which comprises alkylating a compound of the general formula II:
This invention relates to a process for the preparation of 6,7-dialkoxy-4-oxyquinoline-3-carboxyl acid-esters of the general formula:
(I) wherein R1 stands for a C1-4 alkyl group, R2 stands for an alkenyl or alkyl group, containing 3-12 carbon atoms, and R3 stands for a C1-4 alkyl or phenyl-C1-4 alkyl group, which comprises alkylating a compound of the general formula II:
Description
~)41515 The present invention is directed to a new process for the preparation of known 6,7-dialkoxy-4-oxy-quinoline-3-carboxylic acid esters of the general formula I
OH O
R O ~ CoOR3 R O ~ COOR (I) wherein R stands for a C1 4 alkyl group, R stands for an alkenyl or alkyl group containing 3-12 carbon atoms and R3 stands for a C1 4 alkyl or phenyl-C1 4-alkyl group.
The compounds of the formula I are known coccidiostatica.
According to the literature the 6~7-dialkoxy-4-oxy-quinoline~
3-carboxylic acid derivatives have been prepared from 3,4-dialkoxy-aniline derivatives, i.e. the corresponding dialkoxy-groups have been --formed on the benzene ring.
Thus~according to British Patent Specification No. 1~188,364 and French Patent Specification No. 1,531,495 4-decyloxy-3-ethoxy-aniline is condensed with ethoxy-methylene-malon ester (EMME), and the desired 6,7-dialkoxy-substituted quinoline derivative is prepared by subjecting the compound thus obtained to ring~closure.
According to German Patent Specification No. 1,954,189 3,4-di-isobutoxy-anilino-methylene-malon-ester is subjected to ring-closure.
According to German Patent Specification No. 2,058,002 3,4-dialkoxy-aniline is reacted with ortho-formic acid ester and p-toluene-sulphonic acid to yield 6,7-dialkoxy-quinoline derivatives. 6,7-dialkoxy-4-hydroxy-quinoline-qF
. . ~ , .
!:'., ~. "' ' ' : , . . ,:. :
:
l`C~4151S
ester compounds are prepared from 6,7-dialkoxy-4-chloro-quinoline-3-carboxylic acid ester accordinglto USP Specification No. 3~665~oo5.
According to the above mentioned "traditional" methods 6,7-di-alkoxy-4-hydroxy-quinoline-3-carboxylic acid derivatives were prepared from 3,4-dialkoxy-aniline derivatives.
According to the present invention there is provided a process for the preparation of 6,7-dialkoxy-4-oxy-quinoline-3-carboxylic acid derivatives of the general formula I by alkenylating or alkylating the compounds of the general formula II
OH o HO ~ CoOR3 HO ~ CoOR3 ll 1 l (II) Rl ~ ~ A`N ~ 1 ~ ~ ~ N~
H ~-wherein R and R are defined as above.
The disadvantage of the process wherein the coccidiostatic ~
4-oxy-3-carbalkoxy-quinolines were prepared by thermal cyclization is, -that the cyclization takes place at 250 & and thus due to decomposition the product is contaminated and canno~be easily purified. These compounds '; ' ,' ' ' '.
are generally insoluble and the repeated recrystallizations are accompanied with several losses.
According to the present invention the alkylation is preferably ~;-carried out in a solvent which can be used for the purification of the product as well. The preferred reaction temperature is 50-100~C, which is achieved by using water-bath.
From the point of view of the product, it is of great importance, that the last step of the entire synthesis is not a thermal ring-closure, but an alkylation carried out at lower temperature.
~3~
, . .
.
. , ::--.
, ~ :
16~41515 The compounds of the general formula II exist in tautomeric keto- and enol forms.
In the formula I R stands for a straight or branched chain lower alkyl group containing 1-4 carbon atoms, preferably a methyl or ethyl group.
R stands for an alkenyl or alkyl group containing 3-12 carbon atoms, preferably a n-butyl, n-decyl or allyl group.
R stands for alkyl group containing 1-4 carbon atoms, preferably an ethyl group, or a phenyl-C1 4 alkyl group~ preferably a benzyl group.
The alkylation of the new compounds of the general formula II
is preferably carried out with an alkylating agent of high boiling point, most preferably with alky~ halidès. Othèr alkylating agents of high boiling point e.g. p-toluene-sulphonic acid ester may also be used.
The alkylation is preferably carried out in the presence of an acid-binding agent, preferably in the presence of sodium hydride. Other acid binding agents e.g. potassium carbonate may also be used.
According to an advantageous embodiment of the present invention the reaction is carried~lout in an organic solvent, preferably in dimethylformamide.
The reaction may be carried out by heating the reactio~mLxture on a water-bath of a temperature of 100 C, but other temperature inter-vals as 50-15~ C (boiling-point of dimethylformamide) may be applied as well. At a lower temperature the reaction gets very slow.
Further details of the present invention are to be found in the Examples without limiting the scope of the in-,., 1~41515 vention to the Examples.
Example 1 1.38 g (0.005 moles) of 6-hydroxy-7-ethoxy-4-oxy-quinoline-3-carboxylic acid ethyl ester are suspended in 60 ml of warm dimethylformamide, whereafter 0.5 g (0.01 mole) of oily sodium hydride suspension are added at 50C, the latter was flushed with 10 ml of dimethylformamide.
After adding of 1.32 g (0.006 moles) of n-decylbromide the tempera-ture of the waterbath is elevated to 100C and the mixture is stirred for 20 hours. The mixture is evaporated to dryness in vacuo, the residue is taken up in 40 ml of water and the pH of the suspension is adjusted to neutral by adding of diluted hydrochloric acid. me precipitated substance is fil-tered and covered with water. 1.47 g of beige 6-n-decyloxy-7-ethoxy-4-hydroxy-quinoline-3-carboxylic acid ethyl-ester are obtained. Mp.: 230-232C.
Yield: ?1 %. After recrystallization from dimethylformamide white product `
is obtained which melts at 242-244C.
Exam~le 2 Accordir,g to the method described in Example 1, 6-decyloxy-7-ethoxy-quinoline-3-carboxylic acid-benzyl-ester is obtained. Mp. of the crude product is 198C~ after recrystallization the product melts at 202-203C.
Analysis:
Calculated: C 72.62 % H 7.78 % N 2.92 %
Found: C 72.78 % H 7.93 % N 3.04 %.
_xample 3
OH O
R O ~ CoOR3 R O ~ COOR (I) wherein R stands for a C1 4 alkyl group, R stands for an alkenyl or alkyl group containing 3-12 carbon atoms and R3 stands for a C1 4 alkyl or phenyl-C1 4-alkyl group.
The compounds of the formula I are known coccidiostatica.
According to the literature the 6~7-dialkoxy-4-oxy-quinoline~
3-carboxylic acid derivatives have been prepared from 3,4-dialkoxy-aniline derivatives, i.e. the corresponding dialkoxy-groups have been --formed on the benzene ring.
Thus~according to British Patent Specification No. 1~188,364 and French Patent Specification No. 1,531,495 4-decyloxy-3-ethoxy-aniline is condensed with ethoxy-methylene-malon ester (EMME), and the desired 6,7-dialkoxy-substituted quinoline derivative is prepared by subjecting the compound thus obtained to ring~closure.
According to German Patent Specification No. 1,954,189 3,4-di-isobutoxy-anilino-methylene-malon-ester is subjected to ring-closure.
According to German Patent Specification No. 2,058,002 3,4-dialkoxy-aniline is reacted with ortho-formic acid ester and p-toluene-sulphonic acid to yield 6,7-dialkoxy-quinoline derivatives. 6,7-dialkoxy-4-hydroxy-quinoline-qF
. . ~ , .
!:'., ~. "' ' ' : , . . ,:. :
:
l`C~4151S
ester compounds are prepared from 6,7-dialkoxy-4-chloro-quinoline-3-carboxylic acid ester accordinglto USP Specification No. 3~665~oo5.
According to the above mentioned "traditional" methods 6,7-di-alkoxy-4-hydroxy-quinoline-3-carboxylic acid derivatives were prepared from 3,4-dialkoxy-aniline derivatives.
According to the present invention there is provided a process for the preparation of 6,7-dialkoxy-4-oxy-quinoline-3-carboxylic acid derivatives of the general formula I by alkenylating or alkylating the compounds of the general formula II
OH o HO ~ CoOR3 HO ~ CoOR3 ll 1 l (II) Rl ~ ~ A`N ~ 1 ~ ~ ~ N~
H ~-wherein R and R are defined as above.
The disadvantage of the process wherein the coccidiostatic ~
4-oxy-3-carbalkoxy-quinolines were prepared by thermal cyclization is, -that the cyclization takes place at 250 & and thus due to decomposition the product is contaminated and canno~be easily purified. These compounds '; ' ,' ' ' '.
are generally insoluble and the repeated recrystallizations are accompanied with several losses.
According to the present invention the alkylation is preferably ~;-carried out in a solvent which can be used for the purification of the product as well. The preferred reaction temperature is 50-100~C, which is achieved by using water-bath.
From the point of view of the product, it is of great importance, that the last step of the entire synthesis is not a thermal ring-closure, but an alkylation carried out at lower temperature.
~3~
, . .
.
. , ::--.
, ~ :
16~41515 The compounds of the general formula II exist in tautomeric keto- and enol forms.
In the formula I R stands for a straight or branched chain lower alkyl group containing 1-4 carbon atoms, preferably a methyl or ethyl group.
R stands for an alkenyl or alkyl group containing 3-12 carbon atoms, preferably a n-butyl, n-decyl or allyl group.
R stands for alkyl group containing 1-4 carbon atoms, preferably an ethyl group, or a phenyl-C1 4 alkyl group~ preferably a benzyl group.
The alkylation of the new compounds of the general formula II
is preferably carried out with an alkylating agent of high boiling point, most preferably with alky~ halidès. Othèr alkylating agents of high boiling point e.g. p-toluene-sulphonic acid ester may also be used.
The alkylation is preferably carried out in the presence of an acid-binding agent, preferably in the presence of sodium hydride. Other acid binding agents e.g. potassium carbonate may also be used.
According to an advantageous embodiment of the present invention the reaction is carried~lout in an organic solvent, preferably in dimethylformamide.
The reaction may be carried out by heating the reactio~mLxture on a water-bath of a temperature of 100 C, but other temperature inter-vals as 50-15~ C (boiling-point of dimethylformamide) may be applied as well. At a lower temperature the reaction gets very slow.
Further details of the present invention are to be found in the Examples without limiting the scope of the in-,., 1~41515 vention to the Examples.
Example 1 1.38 g (0.005 moles) of 6-hydroxy-7-ethoxy-4-oxy-quinoline-3-carboxylic acid ethyl ester are suspended in 60 ml of warm dimethylformamide, whereafter 0.5 g (0.01 mole) of oily sodium hydride suspension are added at 50C, the latter was flushed with 10 ml of dimethylformamide.
After adding of 1.32 g (0.006 moles) of n-decylbromide the tempera-ture of the waterbath is elevated to 100C and the mixture is stirred for 20 hours. The mixture is evaporated to dryness in vacuo, the residue is taken up in 40 ml of water and the pH of the suspension is adjusted to neutral by adding of diluted hydrochloric acid. me precipitated substance is fil-tered and covered with water. 1.47 g of beige 6-n-decyloxy-7-ethoxy-4-hydroxy-quinoline-3-carboxylic acid ethyl-ester are obtained. Mp.: 230-232C.
Yield: ?1 %. After recrystallization from dimethylformamide white product `
is obtained which melts at 242-244C.
Exam~le 2 Accordir,g to the method described in Example 1, 6-decyloxy-7-ethoxy-quinoline-3-carboxylic acid-benzyl-ester is obtained. Mp. of the crude product is 198C~ after recrystallization the product melts at 202-203C.
Analysis:
Calculated: C 72.62 % H 7.78 % N 2.92 %
Found: C 72.78 % H 7.93 % N 3.04 %.
_xample 3
2.76 g (0.01 mole) of 6-hydroxy-7-ethoxy-4-oxy-quinoline-3-carboxylic acid-ethyl-ester are stirred in 120 ml of warm dimethylformamide, 1.0 g (0.02 moles) of oily sodium hydride suspension is added to the mixture at ;
50C, the suspension is flushed with 20 ml of dimethylformamide. After adding 1.64 g (0.012 moles) of n-butyl-bromide the temperaturè of waterbath is successively elevated to 100C and at this temperature the mixture is stirred .. . .. .; .
1~34151S
for 30 hours. After the reaction time the mixture is evaporated to dry in vacuo and the residue is taken up in 40 ml of water. The pH is adjusted to neutral by adding diluted hydrochloric acid and the precipitated solid sub-stance is filtered, covered with water, thus 3.1 g of 6-n-butoxy-7-ethoxy-4-oxy-quinoline-3-carboxylic acid-ethyl-ester is obtained. Mp.: 220C.
Yield: 93.2 %. After recrystallization the product melts at 257C.
Example 4 The process is the same when reacting the 6-hydroxy-derivative with allyl-bromide, but the reaction time will be 50 hours. Thus 6-allyl-oxy-7-ethoxy-4-oxyquinoline-3-carboxylic acid-ethyl-ester is obtained with a yield of 91.5 %. Mp.: 220C. After recrystallization from dimethylformamide the product melts at 233C.
50C, the suspension is flushed with 20 ml of dimethylformamide. After adding 1.64 g (0.012 moles) of n-butyl-bromide the temperaturè of waterbath is successively elevated to 100C and at this temperature the mixture is stirred .. . .. .; .
1~34151S
for 30 hours. After the reaction time the mixture is evaporated to dry in vacuo and the residue is taken up in 40 ml of water. The pH is adjusted to neutral by adding diluted hydrochloric acid and the precipitated solid sub-stance is filtered, covered with water, thus 3.1 g of 6-n-butoxy-7-ethoxy-4-oxy-quinoline-3-carboxylic acid-ethyl-ester is obtained. Mp.: 220C.
Yield: 93.2 %. After recrystallization the product melts at 257C.
Example 4 The process is the same when reacting the 6-hydroxy-derivative with allyl-bromide, but the reaction time will be 50 hours. Thus 6-allyl-oxy-7-ethoxy-4-oxyquinoline-3-carboxylic acid-ethyl-ester is obtained with a yield of 91.5 %. Mp.: 220C. After recrystallization from dimethylformamide the product melts at 233C.
Claims (11)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Process for the preparation of 6,7-dialkoxy-4-oxy-quinoline-3-carboxylic acid esters of the general formula I
(I) wherein R1 stands for a C1-4 alkyl group, R2 stands for an alkenyl or alkyl group, containing 3-12 carbon atoms, and R3 stands for C1-4 alkyl or phenyl-C1-4-alkyl group, which comprises alkenylating or alkylating a compound of the general formula II
(II) wherein R1 and R3 are defined as above.
(I) wherein R1 stands for a C1-4 alkyl group, R2 stands for an alkenyl or alkyl group, containing 3-12 carbon atoms, and R3 stands for C1-4 alkyl or phenyl-C1-4-alkyl group, which comprises alkenylating or alkylating a compound of the general formula II
(II) wherein R1 and R3 are defined as above.
2. Process according to claim 1, which comprises carrying out the alkenylation or alkylation with an alkenylating or alkylating agent of high boiling point.
3. Process according to claim 1, which comprises carrying out the reaction in the presence of an acid-binding agent.
4. Process according to claim 1, which comprises carrying out the reaction in an organic solvent at 50°- 100°C.
5. Process according to claim 1 in which the alkenylation or alkylation is carried out with an alkenyl or alkyl halide.
6. A process according to claim 5 in which the alkenyl or alkyl halide is alkyl, n-butyl or n-decyl bromide.
7. Process according to claim 1 in which 6-n-decyloxy-7-ethoxy-4-hydroxyquinoline-3-carboxylic acid ethyl ester is prepared by reacting 6-hydroxy-7-ethoxy-4-oxyquinoline-3-carboxylic acid ethyl ester with n-decyl bromide.
8. Process according to claim 1 in which 6-n-decyloxy-7-ethoxy-quinoline-3-carboxylic acid benzyl ester is prepared by reacting 6-hydroxy-7-ethoxy-4-oxyquinoline-3-carboxylic acid benzyl ester with n-decyl bromide.
9. Process according to claim 1 in which 6-n-butoxy-7-ethoxy-4-oxyquinoline-3-carboxylic acid ethyl ester is prepared by reacting 6-hydroxy-7-ethoxy-4-oxyquinoline-3-carboxylic acid ethyl ester with n-butyl bromide.
10. Process according to claim 1 in which 6-allyloxy-7-ethoxy-4-oxyquinoline-3-carboxylic acid ethyl ester is prepared by reacting 6-hydroxy-7-ethoxy-4-oxyquinoline-3-carboxylic acid ethyl ester with allyl bromide.
11. Process according to claim 3 in which the acid-binding agent is sodium hydride.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| HUCI1402A HU167571B (en) | 1973-08-28 | 1973-08-28 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1041515A true CA1041515A (en) | 1978-10-31 |
Family
ID=10994489
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA207,853A Expired CA1041515A (en) | 1973-08-28 | 1974-08-27 | Preparation of 6,7-dialkoxy-4-oxy-quinoline- 3 carboxylic acid ester compounds |
Country Status (14)
| Country | Link |
|---|---|
| AT (1) | AT338788B (en) |
| CA (1) | CA1041515A (en) |
| CH (1) | CH605772A5 (en) |
| CS (1) | CS188334B1 (en) |
| DD (1) | DD113357A1 (en) |
| DK (1) | DK138114B (en) |
| ES (1) | ES429569A1 (en) |
| GB (1) | GB1467224A (en) |
| HU (1) | HU167571B (en) |
| NL (1) | NL7411388A (en) |
| NO (1) | NO145760C (en) |
| PL (1) | PL93796B1 (en) |
| SE (1) | SE404602B (en) |
| SU (1) | SU634666A3 (en) |
-
1973
- 1973-08-28 HU HUCI1402A patent/HU167571B/hu unknown
-
1974
- 1974-08-23 SE SE7410744A patent/SE404602B/en unknown
- 1974-08-26 PL PL1974173678A patent/PL93796B1/pl unknown
- 1974-08-26 AT AT688274A patent/AT338788B/en not_active IP Right Cessation
- 1974-08-27 CH CH1168474A patent/CH605772A5/xx not_active IP Right Cessation
- 1974-08-27 DK DK454674AA patent/DK138114B/en not_active IP Right Cessation
- 1974-08-27 GB GB3744574A patent/GB1467224A/en not_active Expired
- 1974-08-27 ES ES429569A patent/ES429569A1/en not_active Expired
- 1974-08-27 CA CA207,853A patent/CA1041515A/en not_active Expired
- 1974-08-27 SU SU742057142A patent/SU634666A3/en active
- 1974-08-27 NL NL7411388A patent/NL7411388A/en not_active Application Discontinuation
- 1974-08-27 CS CS745898A patent/CS188334B1/en unknown
- 1974-08-27 NO NO743063A patent/NO145760C/en unknown
- 1974-08-28 DD DD180756A patent/DD113357A1/xx unknown
Also Published As
| Publication number | Publication date |
|---|---|
| HU167571B (en) | 1975-11-28 |
| NL7411388A (en) | 1975-03-04 |
| DK138114B (en) | 1978-07-17 |
| PL93796B1 (en) | 1977-06-30 |
| SE7410744L (en) | 1975-03-03 |
| NO743063L (en) | 1975-03-24 |
| DK138114C (en) | 1978-12-18 |
| CH605772A5 (en) | 1978-10-13 |
| DK454674A (en) | 1975-04-28 |
| DD113357A1 (en) | 1975-06-05 |
| NO145760C (en) | 1982-05-26 |
| AT338788B (en) | 1977-09-12 |
| CS188334B1 (en) | 1979-03-30 |
| SE404602B (en) | 1978-10-16 |
| GB1467224A (en) | 1977-03-16 |
| SU634666A3 (en) | 1978-11-25 |
| NO145760B (en) | 1982-02-15 |
| ES429569A1 (en) | 1976-09-16 |
| ATA688274A (en) | 1977-01-15 |
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