CS202637B1 - Process for preparing 1-/5-nitro-2furyl/-2-/5-substituted 1,3,4,-oxadiazolyl/ethenes - Google Patents

Description

CZECHOSLOVAKIASOCIALISTREPUBLIC (19)

DESCRIPTION OF THE INVENTION

TO CERTIFICATE 202 637 »« <B1)

W) (23) Exhibition priority. (22) Entries 24 08 79 (21) PV 5754-79 (51) Int. Cl. C 07 D 413/06

OFFICE OFFICE

AND DISCOVERIES (40) Published 30 04 80 (45) Published 01 06 83 (75)

Author of the Invention POVAŽANEC FRANTIŠEK ing. CSc.

KOVÁČ JAROSLAV prof. DrSc., BRATISLAVA (54) Preparation of 1- (5-nitro-2-furyl) -2- (5-substituted-1,3,4-oxadiazolyl) ethene 1

The present invention provides a novel process for the preparation of 1- (5-nitro-2-furyl) -2- (5-substituted-1,3,4-oxadiazolyl) ethenes. Preparation of 1- (5-nitro-2-furyl) -2- (5-substituted-1,3,4-oxadiazolyl) ethene bole ethanes described by Sugihar and Itom (Yakugaku Zasshi 85, 744 (1965); Chem. Abstr) 63, 13240e (1965)) by cyclizing the cykl, Ν-disubstituted acid hydrazides using POCl 2 as a dehydrating agent. The disadvantage of this method is the long reaction Saxons. Another method used to prepare this group of compounds is the oxidation of N-substituted arylidenehydrazides of 3- (5-nitro-2-furyl / acrylic tetraacetate) (Sasaki T., Yoshioka T.: Bull. Chem. Soo. Japan 42 »2989 (1970)]. The modified Huisgen method was used by Sugihara and Ito in Japanese Patent (Fujisawa Pharmaceutical Co.Ltd. Japan 17586 ('65); Chem. Abstr. 2, 18105a / 1965), where they were placed on 5-substituted tetrazoles with 3- / 5-nitrofuryl chloride. acrylic in xylene and obtain the corresponding 1,3,4-oxadiazoles. The main disadvantage of both methods is the low yields and low product purity.

These disadvantages of the prior art are eliminated by the novel process for the preparation of 1- (5-nitro-2-furyl) -2- (5-substituted-1,3,4-oxadiazolyl) ethenes which shortens the reaction times from 4 to 1 hour to 15-20. minutes while providing products in high yields. 202 637 202 037

Synthesized derivatives are of interest for bactericidal and fungicidal activity (A. Sugihara, H. Ito: Yakugaku Zasshi 8J, 744/1965) and also structurally belong to the same class of substances as Furamizole, which was introduced as a drug in practice in 1971.

According to the invention, the novel process for the preparation of 1- (5-nitro-2-furyl) -2- (5-substituted-1,3,4-oxadiazolyl) ethanes is that 1- (5-nitro-2- furyl (2- [5-substituted-1,3,4-oxadiazolyl] ethenes of general formula (NO-1)

-OH = CH where R is phenyl, 2-furyl, 5- (2-nitrophenyl) -2-furyl, 5- (4-bromophenyl) -2-furyl, 5- (3-chlorophenyl) -2-furyl 5- (2-chlorophenyl) -2-furyl and 5- (4-methoxyphenyl) -2-furyl are prepared by reacting 5-substituted tetrazoles of the formula

NH N

And H- (1 H) wherein R is phenyl, 2-furyl, 5- (2-nitrophenyl) -2-furyl, 5- (4-bromophenyl) -2-furyl, 5- (3-) chloro-phenyl / -2-furyl, 5- (2-chlorophenyl) -2-furyl and 5- (4-methoxyphenyl) -2-furyl, with 3- (5-nitro-2-furyl) acryloylacetylanhydride of formula

in inert solvents such as benzene, toluene, o-, m-, p-xylene, mesitylene, at temperatures from 70 to 140 ° C. The substituted ethylenes obtained are in the form of pure E isomers. The advantage of the process according to the invention is, inter alia, that it allows the preparation of 1- (5-nitro-2-furyl) -2- (5-substituted-1,3,4-oxadiazolyl) ethers by a simple coupling in the course of 15 to 20 minutes, in the simplicity of isolation from the reaction mixtures, the high yields and the stability and availability of the starting substrates.

The following examples illustrate, but are not limited to, the following. Example 1 Preparation of 1- (5-nitro-2-furyl) -2- (5-phenyl-1,3,4-oxadiazolyl) ethene

A mixture of 1.46 g (0.01 mol) of 5-phenyltetrazole, 1.25 g (0.01 mol) of 3- (5-nitro-2-furyl) acryloylacetylanic anhydride and 30 ml of xylene was heated at 138 ° C for 15 minutes. C. After cooling the reaction mixture, the precipitated oxadiazole is filtered off with suction, washed with ethanol and dried. 202 637 1.81 g (64%) of the E isomer of 1- (5-nitro-2-furyl) -2- (5-phenyl-1,3,4-oxadiazolyl) ethene were obtained which crystallized from ethanol of m.p. ° C. Example 2

A mixture of 1.36 g (0.01 mol) of 5- [2-furyl / tetrazole, 1.25 g (0.01 mol) of 3- (5-nitro-2-furyl / acryloylacetylanic anhydride) in 30 ml of toluene is heated at 100 ° C for 20 minutes. After cooling the reaction mixture, the solid residue is filtered off with suction. After crystallization of the crude oxadiazole from ethanol, 1.36 g (50%) of 1- (5-nitro-2-furyl) -2- [5- (2-furyl) -1,3,4-oxadiazolyl] ethene with tt206 to 208 ° C. Example 3

A mixture of 2.52 g (0.01 mole) of 5- 5- (4-methoxyphenyl) -2-furyl tetrazole, 1.25 g (0.01 mole) of 3- (5-nitro-2-furyl / acryloylacetylanic anhydride in 30) ml of benzene was heated at 80 ° C for 20 minutes. After cooling the reaction mixture, the solid residue is filtered off with suction, washed with ethanol and crystallized from ethylene glycol monomethyl ether. 2.46 g (65%) of 1- (5-nitro-2-furyl) -2- [5- (4-methoxyphenyl) -2-furyl] -1,3,4-oxadiazolyl / ethene are obtained mp 234-235 ° C.

Table 1

Physical constants 1- (5-nitro-2-furyl) -2- (5-X-2-furyl) -1,4,4-oxadiazolyl] ethene X Synthesis Molecular Weight T.t.c. You calculated / calculated # C% H% N 2-K02CfiH4 394.30 230 to 231 55.05 2.55 14.21 C18H10N4 ° 7 75 54.93 2.54 14.11 4-BrC6H4a 428.21 225 to 226 50.60 2.36 9.83 C18H10BrN3 ° 5 72 50.38 2.44 9.71 3-ClC6H4b 383.75 234 to 235 56.55 2.63 10.95 C18H10C1N3 ° 5 68 56.68 2, 71 10.63 2-C1C6h4 ° 383.75 212 to 213 .56.55 2.63 10.95 C18 »10C1N305 70 56.53 2.71 10.71 4-CH30CgH4 379.33 234 to 235 60.20 3 , 46 11.09 C19H13N3 ° 6 65 60.29 3.50 10.88 Hd 273.20 206 to 208 tt 206-7 ° C (C 12 H 7 N 3 O 5 50 Y® 283.23 235 to m.p. 235 ° C / / G 14 H 9 N 3 ° 4 64

Claims (1)

202 037 8 * Br calculated / tent. 18.67 / 18.75; b% Cl 9.26 / 9.23; 0% Cl 9.26 / 9.17; d was crystallized from ethanol, and the allys of the synthesized substance were crystallized from mono-thylene glycol to summer; Y is phenyl. BACKGROUND OF THE INVENTION The preparation of 1- (5-nitro-2-furyl) -2- (5-aubatite-1,3,4-oxadiazolyl) ethene-general formula (2) CH = CH wherein R is phenyl, 2-furyl, 5 - (2-nitrophenyl) -2-furyl, 5- (4-bromophenyl) -2-furyl, 5- (3-chlorophenyl) -2-furyl, 5- (2-fluorophenyl) -2-furyl and 5-furyl; - (4-methoxyphenyl) -2-furyl, characterized in that the 5-substituted tetrazoles of general formula wherein R is phenyl, 2-furyl, 5- (2-nitrophenyl) -2-furyl, 5- (4-bromophenyl) -2-furyl, 5- (3-chlorophenyl) -2-furyl, 5- [ 2-chlorophenyl / -2-furyl and 5- (4-methoxyphenyl) -2-furyl are treated with 3- (5-nitro-2-furyl / acryloylacetylanhydride) with NO; CH = CH-CO-O-CO-CH3 in an inert solvent such as bensene, toluene, ο-, η-, p -ylene and mesitylene, at temperatures from 70 to 140 ° C. Printed by Moravian Printing Works, Operation 12, Leninova 21, Olomouc Price; 2,40 Kčs