- Solid-Phase Parallel Synthesis of N-Substituted-2-aminothiazolo[4,5-b]pyrazine Derivatives via Tandem Reaction of Isothiocyanate Terminated Resin with o-Bromo-2-Aminopyrazines
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A novel solid-phase synthesis methodology of N-substituted-2-aminothiazolo[4,5-b]pyrazine derivatives was developed. The key step in this synthesis strategy is the tandem reaction of isothiocyanate terminated resin 2 with o-bromo-2-aminopyrazine, affording cyclized 2-aminothiazolo[4,5-b]pyrazine resin 4. To increase the diversity of our library, Suzuki coupling reaction was performed at the position C6. Further functionalization of 2-aminothiazolo[4,5-b]pyrazine core skeleton with various electrophiles such as alkyl halides, acyl chlorides, and sulfonyl chlorides and cleavage from the resin with TFA in DCM generated N-alkyl-, N-acyl-, and N-sulfonyl-2-aminothiazolo[4,5-b]pyrazine derivatives. The physicochemical properties and the polar surface areas of synthesized compounds were evaluated.
- Abdildinova, Aizhan,Yang, Seung-Ju,Gong, Young-Dae
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- ACETIC ACID AMIDE DERIVATIVE HAVING INHIBITORY ACTIVITY ON VASCULAR ENDOTHELIAL LIPASE
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Disclosed is a compound which is useful as an endothelial lipase inhibitor. A pharmaceutical composition having inhibitory activity on endothelial lipase comprising a compound represented by the formula: , its pharmaceutically acceptable salt, or a solvate thereof, wherein Ring A is nitrogen-containing hetero ring, Ring A may be substituted with a substituent other than a group represented by the formula: -C(R1R2)-C(=O)-NR3R4 and a group represented by the formula: -R5, a broken line represents the presence or the absence of a bond, Z is -NR6-, =N-, -O-, or -S-, R6 is halogen, substituted or unsubstituted alkyl or the like, R1 and R2 are each independently hydrogen, halogen, hydroxy, cyano, nitro, carboxy or substituted or unsubstituted alkyl, R3 is hydrogen or substituted or unsubstituted alkyl, R4 is hydrogen, substituted or unsubstituted alkyl or the like, R3 and R4 taken together with the adjacent nitrogen atom to which they are attached may form a substituted or unsubstituted ring, R5 is hydrogen, halogen, hydroxy, cyano, nitro, carboxy, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl or the like.
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Page/Page column 74
(2011/08/08)
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- TRANSFORMATIONS OF 1,2,4-THIADIAZOLO/2,3-x/AZINES
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Hydrolysis of 1,2,4-thiadiazolo/2,3-c/pyrimidine derivative 2 produced cyanoaminopyrimidine 4, while treatment of 1,2,4-thiadiazolo/2,3-b/pyridazine 5 with hydrazine hydrate gave thiourea derivative 7. 1,2,4-Thiadiazolo/2,3-a/pyridine 8 and 1,2,4-thiadiazolo/2,3-a/pyrazine 9 gave by alkaline hydrolysis the corresponding pyridopyrimidine 10 and pteridine 11, respectively.The compound 10 was converted with phenacyl bromide into 14 and further cyclized in PPA into pyrido/2,3-d/thiazolo/2,3-a/pyrimidine 15.Pyrazinylthiourea derivative 16 was cyclized in acidic solution into thiazolo/4,5-b/pyrazine 17, which was converted by hydrolysis and decarboxylation into amino derivative 20.This gave with ethyl acetoacetate pyrazino/2',3':4,5/thiazolo/3,2-a/pyrimidine 23. 1,2,4-Thiadiazoloazines 24 and N-ethoxycarbonyl-N'-azinylthioureas 25 were transformed with hydrogen peroxide into urea derivatives 26.
- Koren, Bozidar,Stanovnik, Branko,Tisler, Miha
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p. 689 - 697
(2007/10/02)
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