Month: March 2022

With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.36725-28-7,6-(4-Aminophenyl)-5-methyl-4,5-dihydropyridazin-3(2H)-one,as a common compound, the synthetic route is as follows.

Example 1 (Intermediate Compound) (R)-6-(4-hydrazino-phenyl)-5-methyl-4,5-dihydro-2H-pyridazin-3-one A slight modification on the procedure described in J.Med.Chem. (1990), 33(10), 2870-2875 was used as follows. A solution of sodium nitrite (1.7 g) in water (12.5 ml) was added slowly at 0-5 C. to a solution of (R)-6-(4-aminophenyl)-5-methyl-4,5-dihydro-2H-pyridazin-3-one (5 g) in 1 M hydrochloric acid (75 ml). The resulting solution was stirred on ice bath for five minutes and then added slowly to a solution of tin(II)chloride dihydrate (17 g) in 1 M hydrochloric acid (150 ml) keeping the reaction temperature below 5 C. This solution was stirred on ice for forty minutes and then a solution of 50% NaOH (75 ml) was quickly added. The resulting mixture was stirred on ice bath until the temperature reached zero degrees Celsius. The crystals were filtered and washed with dilute ammonia. Yield: 5.0 g, 93%. HPLC: enantiomerically pure. 1H NMR (400 MHz, DMSO-d6): delta=1.04 (d, 3H, CH3), 2.17 (d, 1H, J=16 Hz), 2.60 (m, 1H), 3.29 (m, 1H), 4.04 (s, 2H, NH2), 6.77 (d, 2H, J=8 Hz), 7.09 (b, 1H, NH), 7.54 (d, 2H, J=8 Hz), 10.66 (s, 1H, NHCO)., 36725-28-7

As the paragraph descriping shows that 36725-28-7 is playing an increasingly important role.

Reference：
Patent; Pystynen, Jarmo; Pippuri, Aino; Luiro, Anne; Nore, Pentii; Backstrom, Reijo; Lonnberg, Kari; Haikala, Heimo; Levijoki, Jouko; Kaheinen, Petri; Kaivola, Juha; US2003/158200; (2003); A1;,
Pyridazine – Wikipedia
Pyridazine | C4H4N2 – PubChem

With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.1352925-63-3,Ethyl 4,6-dihydroxypyridazine-3-carboxylate,as a common compound, the synthetic route is as follows.

In a 5000 ml rb flask, ethyl 4,6-dihydroxypyridazine-3-carboxylate (200 g, 1086 mmol) was dissolved in THF (2000 mL), methanol (1000 mL) and water (800 mL). LiOH (137 g, 3258 mmol) was added slowly at rt and stirred at rt for 3-4 hr. The starting material was gone. The solvent was removed at 50 C. under reduced pressure to afford a yellow solid. The solid was acidified with aqueous HCl solution (400 ml) (1:1 ratio) at 0 C. and stirred at rt for 30-40 minutes. The solid was filtered and washed with water. It was then dried under vacuum for 1-2 hr. This solid was taken into 300 ml of methanol:DCM (2:8) and stirred at rt for 20-25 minutes. The mixture was filtered and the solid was washed with methanol and dried under vacuum for 1 hr. The desired product was obtained as a yellow solid, 4,6-dihydroxypyridazine-3-carboxylic acid (153 g, 951 mmol, 88% yield). MS (M+1) m/z: 156.9 (MH+). LC retention time 0.31 min [A]. 1H NMR (400 MHz, deuterium oxide) delta 6.00-5.34 (m, 1H), 4.75 (s, 7H)

1352925-63-3, As the paragraph descriping shows that 1352925-63-3 is playing an increasingly important role.

Reference：
Patent; BRISTOL-MYERS SQUIBB COMPANY; Liu, Chunjian; Yang, Michael G.; Xiao, Zili; Chen, Ling; Moslin, Ryan M.; Tokarski, John S.; Weinstein, David S.; (84 pag.)US2019/152948; (2019); A1;,
Pyridazine – Wikipedia
Pyridazine | C4H4N2 – PubChem

446273-59-2, 3-Amino-4-bromo-6-chloropyridazine is a pyridazine compound, ?involved in a variety of chemical synthesis. Rlated chemical reaction is continuously updated

4-bromo-6-chloro-pyridazin-3-amine (30.02 g, 143 mmol) and THF (180 mL) were charged into a reaction vessel. Methylmagnesium chloride (22% in THF, 50.0 mL, 1.03 eq.) was added at 20C over 60 minutes, followed by zinc chloride in Me-THF (25%, 37 mL, 0.50 eq.) and palladium tetrakis(triphenyphosphine) (1.66 g, lmol%). The reaction mixture was heated to 50C and methylmagnesium chloride (22% in THF, 81 mL, 1.7 eq.) was added slowly. The reaction mixture was stirred at 50C until complete conversion, then at 10C for 14.5 hours and poured into a mixture of water (90 g), aqueous HCl 33% (52.5 g) and toluene (150 mL) maintained at 20-30C. The aqueous phase was separated and the organic phase was extracted with a solution of aqueous HCl 33% (2.0 g) and water (45 g). The aqueous layers were combined and washed with toluene (30 mL) twice and the pH was adjusted by addition of 25% aqueous ammonia solution. When a pH of 2.4 was reached, seeding crystals were added, the mixture was stirred further for 15 minutes and thereafter the pH was brought to 4.0. The suspension was stirred at 20C for 2 hours, the precipitate was filtered off, washed with water (20 mL) three times to afford crude 6- chloro-4-methyl-pyridazin-3-amine (29 g) as a brown solid. (0302) 29 g crude product was transferred to a reaction vessel and methanol (20 mL) was added. The mixture was refluxed for 30 minutes and 12 g water was added. The solution was cooled to 0C and stirred for 2 hours at this temperature. The precipitate was filtered off, washed with water three times and dried under reduced pressure at 40C to afford purified 6-chloro-4-methyl-pyridazin-3-amine (13.8 g, 66%) as a light brown solid. (0303) Alternative purification: (0304) 50 g crude 6-chloro-4-methyl-pyridazin-3-amine were dissolved in methanol (250 mL) and active charcoal (4.0 g) and diatomaceous earth (2.5 g) were added. The suspension was stirred at 45C for 1 hour, cooled to 30C and potassium hydrogenophosphate (2.1 g) was added. The suspension was stirred at 30C for another 90 minutes, filtered and the precipitate washed with methanol (100 mL). The filtrate was concentrated to a residual volume of 175 mL and water (120 mL) was added. The resulting suspension was heated to reflux affording a solution which was cooled to 20C resulting in a suspension. The precipitate was filtered off, washed with water (90 mL) and dried under reduced pressure to afford pure 6-chloro-4-methyl-pyridazin-3-amine (38 g, 76%) as a light yellow solid.

446273-59-2, As the paragraph descriping shows that 446273-59-2 is playing an increasingly important role.

Reference：
Patent; F. HOFFMANN-LA ROCHE AG; HOFFMANN-LA ROCHE INC.; ADAM, Jean-Michel; FANTASIA, Serena Maria; FISHLOCK, Daniel Vincent; HOFFMANN-EMERY, Fabienne; MOINE, Gerard; PFLEGER, Christophe; MOESSNER, Christian; (73 pag.)WO2019/57740; (2019); A1;,
Pyridazine – Wikipedia
Pyridazine | C4H4N2 – PubChem

With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.108784-42-5,6-Fluoropyridazin-3-amine,as a common compound, the synthetic route is as follows.

6-Fluoropyridazin-3-ylamine (10 g, 89 mmol) was combined with a 50% (w/v) aqueous solution of chloroacetaldehyde (23 mL, 177 mmol) in n-butanol (150 mL) and stirred at reflux for 1h. The cooled reaction solution was reduced in volume and diluted with diethyl ether to precipitate a brown solid, which was collected by filtration, to yield 12.0 g of the titled compound. LRMS (ESI) m/z 138.0[(M+H)]+,calc?d for C6H4FN3: 137.12., 108784-42-5

108784-42-5 6-Fluoropyridazin-3-amine 13719068, apyridazine compound, is more and more widely used in various fields.

Reference：
Article; Kostich, Walter; Hamman, Brian D.; Li, Yu-Wen; Naidu, Sreenivasulu; Dandapani, Kumaran; Feng, Jianlin; Easton, Amy; Bourin, Clotilde; Baker, Kevin; Allen, Jason; Savelieva, Katerina; Louis, Justin V.; Dokania, Manoj; Elavazhagan, Saravanan; Vattikundala, Pradeep; Sharma, Vivek; Das, Manish Lal; Shankar, Ganesh; Kumar, Anoop; Holenarsipur, Vinay K.; Gulianello, Michael; Molski, Ted; Brown, Jeffrey M.; Lewis, Martin; Huang, Yanling; Lu, Yifeng; Pieschl, Rick; O’malley, Kevin; Lippy, Jonathan; Nouraldeen, Amr; Lanthorn, Thomas H.; Ye, Guilan; Wilson, Alan; Balakrishnan, Anand; Denton, Rex; Grace, James E.; Lentz, Kimberley A.; Santone, Kenneth S.; Bi, Yingzhi; Main, Alan; Swaffield, Jon; Carson, Ken; Mandlekar, Sandhya; Vikramadithyan, Reeba K.; Nara, Susheel J.; Dzierba, Carolyn; Bronson, Joanne; Macor, John E.; Zaczek, Robert; Westphal, Ryan; Kiss, Laszlo; Bristow, Linda; Conway, Charles M.; Zambrowicz, Brian; Albright, Charles F.; Journal of Pharmacology and Experimental Therapeutics; vol. 358; 3; (2016); p. 371 – 386;,
Pyridazine – Wikipedia
Pyridazine | C4H4N2 – PubChem

446273-59-2, 3-Amino-4-bromo-6-chloropyridazine is a pyridazine compound, ?involved in a variety of chemical synthesis. Rlated chemical reaction is continuously updated,446273-59-2

6-Chloro-4-methylpyridazin-3-amineA 100 mL flask was charged with 4-bromo-6-chloropyridazin-3-amine (1 g, 4.80 mmol), dimethylzinc (9.59 mL, 9.59 mmol), Pd(PPh3)4 (0.277 g, 0.240 mmol) and DMF (10 mL). The reaction mixture was stirred at RT. Then the reaction mixture was quenched with MeOH and concentrated. The crude product was loaded onto a 10 g SCX SPE, and 3 volumes of MeOH followed by 3 volumes of 2N ammonia in MeOH were added. The fractions were combined and concentrated to afford 6-chloro-4-methylpyridazin-3-amine (693 mg, 80% yield).

446273-59-2 3-Amino-4-bromo-6-chloropyridazine 22024419, apyridazine compound, is more and more widely used in various fields.

Reference：
Patent; GLAXOSMITHKLINE LLC; BROOKS, Carl; CHEUNG, Mui; EIDAM, Hilary, Schenck; GOODMAN, Krista, B.; HAMMOND, Marlys; HILFIKER, Mark, A.; HOANG, Tram, H.; PATTERSON, Jaclyn, R.; STOY, Patrick; YE, Guosen; WO2013/12500; (2013); A1;,
Pyridazine – Wikipedia
Pyridazine | C4H4N2 – PubChem

With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.1352925-63-3,Ethyl 4,6-dihydroxypyridazine-3-carboxylate,as a common compound, the synthetic route is as follows.

Step 3[00162j To a 350 mL nitrogen purged Schlenk flask containing Int2 (3.77 g, 20.47 mmol) was added phosphorus oxychloride (38 mL, 408 mmol). The vessel was sealed and heated to 100 C for 3.5 hours. The reaction was cooled to room temperature and the excess phosphorus oxychloride was removed in vacuo. The crude oil was dissolved into chloroform, re-concentrated and then poured into ice water, rinsing with ethyl acetate.The two layers were transferred to a separatory funnel, separated and the aqueous layer extracted 3x with ethyl acetate. The combined organic layers were washed twice with water and once with brine (saturated aqueous sodium chloride) and then dried over sodium sulfate, filtered, concentrated and then purified by automated chromatography (5- 90% EtOAc:hexanes), providing Int3 (3.64 g, 16.3 mmol). ?H NMR (400MHz, chloroform-d) oe 7.70 (s, 1H), 4.55 (qd, J=7.1, 1.1 Hz, 2H), 1.46 (td, J=7.2, 0.9 Hz, 3H). LC retention time 0.79 [J]. MS(E) m/z: 221 (MHj., 1352925-63-3

1352925-63-3 Ethyl 4,6-dihydroxypyridazine-3-carboxylate 69007765, apyridazine compound, is more and more widely used in various fields.

Reference：
Patent; BRISTOL-MYERS SQUIBB COMPANY; MOSLIN, Ryan M.; WEINSTEIN, David S.; WROBLESKI, Stephen T.; TOKARSKI, John S.; KUMAR, Amit; WO2014/74661; (2014); A1;,
Pyridazine – Wikipedia
Pyridazine | C4H4N2 – PubChem