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1-[4-(pyridin-2-yl)phenyl]-4(S)-hydroxy-5(S)-2,5-diamino-6-phenyl-2-azahexane trihydrochloride[ No CAS ]
[ 198904-31-3 ]
Yield
Reaction Conditions
Operation in experiment
84%
With 4-methyl-morpholine; diisopropyl-carbodiimide; In dichloromethane; isopropyl alcohol; at -10 - 20℃;Inert atmosphere;Product distribution / selectivity;
Example 1 : Preparation of atazanavir using 1 equivalent of compound (II), 3.5 equivalents of compound (III), 3.5 equivalents of DIC, and 6.6 equivalents of NMM97.5 g of 1 -[4-(piridyn-2-yl)phenyl-4(S)-hydroxy]-5-(S)-2,5-diamino-6-phenyl- 2-azahexane trihydrochloride (trihydrochloride of compound (II) with a 10%wt content of isopropanol, 185.97mmol) were suspended into 683 ml of dichloromethane under nitrogen atmosphere at -10 0C. 135 ml_ (1227.40 mmol) of /V-methylmorpholine were added maintaining the temperature at -10 0C.Separately, 100.8 ml_ (650.90 mmol) of N,N-diisopropylcarbodiimide were added to a suspension of 123.2 g (650.90 mmol) of N-(methoxycarbonyl)-L- tert-leucine (compound (III)) into 975 ml of dichloromethane.Then, the first suspension was quickly transferred over the second one. The resulting mixture was warmed up to room temperature and was maintained at such temperature until the reaction was completed (93% atazanavir by HPLC, monoimpurity content: 1.2%). The reaction mixture was filtered off and was washed with 800 ml_ of water. Then, the organic phase was concentrated up to half volume and 500 ml_ of tert-butylmethylether were added. The mixture was concentrated again up to half volume. This operation was repeated three times up to a dichloromethane content equal or less to 20%. The precipitated product was recovered by filtration. 125.4 g of atazanavir were obtained (Yield =96%). Purity by High Performance Liquid Chromatography (HPLC) = 98.2%, with 4% of N,N-diisopropylurea (DIU) and free of the other probable diastereomers. Molar yield =92%. Recrystallization in ethanol/water 45:55 yielded 105.34 g of atazanavir (149.5 mmol). Recrystallization yield: 84%. Purity HPLC = 99.4%, free of DIU, and free of the other probable diastereomers.The formula of the three probable diastereomers and the HPLC conditions to detect their presence are included below:d-ld-ll d-lHPLC conditions:Liquid chromatograph with UV detector equipped with automatic injector, and integration systemColumn: ZORBAX Eclipse XDB-C18 150x4.6 mm, 5mum.Mobile phase: A (0.05% formic acid in water) and B (ACN)Gradient elution:Detection: 254 nmFlow: 1 mL/minColumn temperature: 25 0CInjection: 2 muLTime injection and chromatogram: 20 minRelative retention time of the diastereomers (RRT):
(2S,3S)-3-amino-4-phenyl-1-(1-(4-(pyridin-2-yl)benzyl)hydrazinyl)butan-2-ol hydrochloride[ No CAS ]
[ 162537-11-3 ]
[ 198904-31-3 ]
Yield
Reaction Conditions
Operation in experiment
To another flask N-methoxycarbonyl-(L)-tertiary leucine (V) (88.1 1 g, 0.47 mole), 1- (3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) (89.4 g, ' 0.47 mole), 1 -Hydroxy-benzotriazole (HOBT) (75.5 g, 0.49 mole) and dichloromethane (1000 mL) were charged and stirred at 25 - 30C for 4 - 5 hours. The aqueous layer of diamino compound (IV) obtained above in part A, and N, N-diisopropylethyl amine (DIPEA) (182.8 mL, 138 g) were added and stirred for 3 hours. The reaction mass was then washed with water, sodium bicarbonate solution and brine. The dichloromethane layer was concentrated to 100 - 150 ml_. Ethyl acetate (1000 ml.) was added and about half of the mixture of solvent was distilled out. n-Heptane (400 mL) was added and stirred for 1 hour at 65C. Cooled to 30C, solid was filtered, washed with mixture of ethyl acetate and n-heptane and dried to afford 101' g of atazanavir base (crude).
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