Claims for Patent: 3,669,966

Summary for Patent: 3,669,966

Title:	PYRAZINE DERIVATIVES AND PROCESS FOR THEIR PREPARATION
Abstract:	Pyrazine derivatives wherein a pyrazine ring is introduced into benzenesulphonyl-urea compounds, typified by the compound are disclosed. These compounds have hypoglycemic properties and are useful in the treatment of diabetic conditions.
Inventor(s):	Ambrogi; Vittorio (Bresso, IT), Logemann; Willy (Milan, IT)
Assignee:	Carlo Erba S.p.A. (Milan, IT)
Application Number:	05/022,389
Patent Claims:	1. A compound of the formula wherein R.sub.1, R.sub.2 and R.sub.3 are independently selected from the group consisting of hydrogen, halogen, lower alkyl, lower alkoxy and amino, and R.sub.4 is selected from the group consisting of lower alkyl and cycloaliphatic of five to eight carbon atoms. 2. The compound as claimed in claim 1, wherein said cycloaliphatic radical is a cycloalkyl radical of five to six carbon atoms. 3. The compound as claimed in claim 1 wherein said compound is N-{ 4-[.beta.-(pyrazine-2-carboxy-amido)-ethyl]-benzene-sulphonyl} -N'-cyclo-hexyl-urea. 4. The compound as claimed in claim 1 wherein said compound is N-{4-[.beta.-(6-methoxy-pyrazine-2-carboxy-amido)-ethyl]-benzene-sulphonyl } -N'-cyclo-hexyl-urea. 5. The compound as claimed in claim 1 wherein said compound is N-{4-[.beta.-(6-chloro-pyrazine-2-carboxy-amido)-ethyl]-benzene-sulphonyl} -N'-cyclo-hexyl-urea. 6. The compound as claimed in claim 1 wherein said compound is N-{ 4-[.beta.-(5-methyl-pyrazine-2-carboxy-amido)-ethyl]-benzene-sulphonyl} -N'-cyclo-hexyl-urea. 7. The compound as claimed in claim 1 wherein said compound is N-{ 4-[.beta.-(2,3-dimethyl-pyrazine-5-carboxy-amido)-ethyl]-benzene-sulphonyl } N-'-cyclo-hexyl-urea. 8. The compound as claimed in claim 1 wherein said compound is N-{ 4-[.beta.-(3-chloro-pyrazine-2-carboxy-amido)-ethyl]-benzene-sulphony} -N'-cyclo-hexyl-urea. 9. The compound as claimed in claim 1 wherein said compound is N-{ 4-[.beta. -(2-chloro-5,6-dimethyl-pyrazine-3-carboxy-amido)-ethyl]-benzene -sulphonyl} -N'-cyclo-hexyl-urea. 10. The compound as claimed in claim 1 wherein said compound is N-{ 4-[.beta.-(3-methoxy-pyrazine-2-carboxy-amido)-ethyl]-benzene-sulphonyl} -N'-cyclo-hexyl-urea. 11. The compound as claimed in claim 1 wherein said compound is N-{ 4-[.beta.-(6-methyl-pyrazine-2-carboxy-amido)-ethyl]-benzene-sulphonyl} -N'-cyclo-hexyl-urea. 12. The compound as claimed in claim 1 wherein said compound is N-{ 4-[.beta.-(5-methoxy-pyrazine-2-carboxy-amido)-ethyl]-benzene-sulphonyl} -N'-cyclo-hexyl-urea. 13. Process for the preparation of a compound of the formula wherein R.sub.1, R.sub.2 and R.sub.3 are independently selected from the group consisting of hydrogen, halogen, lower alkyl, lower alkoxy, hydroxy, amino, acetylamino and phenyl, wherein the lower alkyl, lower alkoxy and phenyl radicals may be substituted by at least one member selected from the group consisting of halogen, lower alkyl, lower alkoxy, R.sub.4 is selected from the group consisting of lower alkyl, lower alkenyl and cycloaliphatic of five to eight carbon atoms, wherein the cycloaliphatic radical may be substituted by at least one member selected from the group consisting of lower alkyl and lower alkoxy, said process comprising reacting at a temperature of 0.degree. to 200 .degree. C. a first compound of the formula wherein R.sub.5 is an isocyanate or amino group or a urethane or urea residue with a second compound of the formula R.sub.4 Y wherein Y is an amine or an isocyanate radical. 14. The process as claimed in claim 13 wherein R.sub.5 is selected from the group consisting of 15. Process for the preparation of a compound of the formula wherein R.sub.1, R.sub.2 and R.sub.3 are independently selected from the group consisting of hydrogen, halogen, lower alkyl, lower alkoxy, hydroxy, amino, acetylamino and phenyl, wherein the lower alkyl, lower alkoxy and phenyl radicals may be substituted by at least one member selected from the group consisting of halogen, lower alkyl, lower alkoxy, R.sub.4 is selected from the group consisting of lower alkyl, lower alkenyl and cycloaliphatic of five to eight carbon atoms, wherein the cycloaliphatic radical may be substituted by at least one member selected from the group consisting of lower alkyl and lower alkoxy, said process comprising reacting at temperature of 0.degree. to 160 .degree. C. a first compound of the formula wherein X is a carboxy group, an acid halide or a mixed anhydride, with a compound of the formula