[C:1]([C:3]1[N:4]=[CH:5][C:6]([NH:9][C:10](=[O:17])[CH2:11][CH2:12][C:13]([O:15][CH3:16])=[O:14])=[N:7][CH:8]=1)#[N:2].[N-:18]=[N+:19]=[N-:20].[Na+].[Cl-].C([NH+](CC)CC)C>CN1CCCC1=O.O>[O:17]=[C:10]([NH:9][C:6]1[CH:5]=[N:4][C:3]([C:1]2[NH:20][N:19]=[N:18][N:2]=2)=[CH:8][N:7]=1)[CH2:11][CH2:12][C:13]([O:15][CH3:16])=[O:14]A mixture of methyl 4-[(5-cyanopyrazin-2-yl)amino]-4-oxo-butanoate A4 (0.168 g, 0.7173 mmol), sodium azide (0.141 g, 0.076 mL, 2.15 mmol) and triethylammonium chloride (0.156 g, 0.146 mL, 1.11 mmol) was stirred 4 h at 150° C. in 1-methyl-2-pyrrolidinone (10 mL). The mixture was cooled down and diluted with water. After acidification with aqueous hydrochloric acid (1N), the filtrate was extracted twice with ethyl acetate. The combined organic phases were combinated, dried over sodium sulfate and concentrated. The residue was suspended in ethyl acetate and filtered to methyl 4-oxo-4-[[5-(1H-tetrazol-5-yl)pyrazin-2-yl]amino]butanoate A36 (0.085 g, 43% yield). M.p.: 270-274° C. LC-MS (Method F): RT 0.49, 278 (M+H+)
Wird geladen…
