Category: 1101120-37-9

Reference of 1101120-37-9, With the rapid development and complex challenges of chemical substances, the synthesis of new drugs is usually one of the most effective ways to increase yield.1101120-37-9, name is Pyrazolo[1,5-a]pyridin-5-amine, molecular formula is C7H7N3, molecular weight is 133.15, as common compound, the synthetic route is as follows.

Decarboxylation of ester 3l (1.29 g, 2.98 mmol), except with carrying out the aqueous extraction from pH 12, gave pyrazolo[1,5-a]pyridin-5-amine (7l) as a pale brown solid (310 mg, 78%). 1H NMR delta (400 MHz, CDCl3) 8.23 (d, J = 7.4 Hz, 1H), 7.79 (d, J = 2.0 Hz, 1H), 6.58 (d, J = 2.4 Hz, 1H), 6.22 (dd, J = 7.4, 2.4 Hz, 1H), 6.13 (d, J = 2.0 Hz, 1H), 3.81 (s, 2H). LC-MS (APCI+) 134 (MH+, 100%). A solution of NaNO2 (27 mg, 0.39 mmol) in water (1 mL) was added dropwise to a solution of 7l (40 mg, 0.30 mmol) and CuCl (74 mg, 0.75 mmol) in concentrated HCl (1 mL) at 0 C over 2 min. After 30 min, the reaction mixture was heated to 80 C for 15 min, and then cooled to room temperature, basified to pH 10 with 1 M NaOH, filtered through a plug of celite and washed with CH2Cl2. The layers of the filtrate were separated and the aqueous layer extracted with CH2Cl2. The combined extracts were dried (Na2SO4) and the solvent removed in vacuo. Chromatography (eluting with hexanes: EtOAc 3:1) gave 5-chloropyrazolo[1,5-a]pyridine (7o) as a white solid (6 mg, 13%). 1H NMR delta (400 MHz, CDCl3) 8.38 (d, J = 7.4 Hz, 1H), 7.95 (d, J = 2.2 Hz, 1H), 7.53 (d, J = 1.8 Hz, 1H), 6.71 (dd, J = 7.4, 2.2 Hz, 1H), 6.47 (d, J = 1.8 Hz, 1H). LC-MS (APCI+) 153 (MH+ with 35Cl, 100%), 155 (MH+ with 37Cl, 30%). Vilsmeier reaction of 7o (6 mg, 0.039 mmol) gave 4o as a white solid (7 mg, 100%).

Statistics shows that 1101120-37-9 is playing an increasingly important role. we look forward to future research findings about Pyrazolo[1,5-a]pyridin-5-amine.

Reference:
Article; Kendall, Jackie D.; O’Connor, Patrick D.; Marshall, Andrew J.; Frederick, Raphael; Marshall, Elaine S.; Lill, Claire L.; Lee, Woo-Jeong; Kolekar, Sharada; Chao, Mindy; Malik, Alisha; Yu, Shuqiao; Chaussade, Claire; Buchanan, Christina; Rewcastle, Gordon W.; Baguley, Bruce C.; Flanagan, Jack U.; Jamieson, Stephen M.F.; Denny, William A.; Shepherd, Peter R.; Bioorganic and Medicinal Chemistry; vol. 20; 1; (2012); p. 69 – 85;,
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem

Reference of 1101120-37-9, Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps,and cheap raw materials. 1101120-37-9, name is Pyrazolo[1,5-a]pyridin-5-amine. A new synthetic method of this compound is introduced below.

A solution of the appropriate carboxylic acid (1 eq.) and the appropriate amine (1.1-1.5 eq.) in pyridine (about 0.1M) was heated to 60 C., and T3P (50% in ethyl acetate, 15 eq.) was added dropwise. Alternatively, T3P was added at RT and the mixture was then stirred at RT or heatedto 60 to 90 C. Afier 1-20 h, the reaction mixture was cooled to RT, and water and ethyl acetate were added. The aqueous phase was extracted with ethyl acetate. The combined organic phases were washed with aqueous buffer solution (pH=5), with saturated aqueous sodium bicarbonate solution and with saturated aqueous sodium chloride solution, dried over sodium sulphate and concentrated under reduced pressure. The crude product was then optionally purified either by normal phase chromatography (mobile phase: cyclohexane/ethyl acetate mixtures or dichloromethane/methanol mixtures) or by preparative RP-HPLC (water/acetonitrile gradient or water/methanol gradient).; 193 mg (583 jtmol.) of 2-{5-[(benzyloxy)carbo- nyl]-4-hydroxy-2-oxopyridin- 1 (2H)-yl}butanoic acid (race- mate) and 116 mg (874 jtmol. 1.5 eq.) of pyrazol[i,5-a] pyridine-5-amine were reacted according to General Method SD. Yield: 233 mg (purity 94%, 84% of theory)j0872] LC/MS [Method 1]: R=0.9S mm; MS (ESIpos):mlz=447 (M+H).

At the same time, in my other blogs, there are other synthetic methods of this type of compound,1101120-37-9, Pyrazolo[1,5-a]pyridin-5-amine, and friends who are interested can also refer to it.

Reference:
Patent; Bayer Pharma Aktiengesellschaft; ROeHRIG, Susanne; HILLISCH, Alexander; STRASSBURGER, Julia; HEITMEIER, Stefan; SCHMIDT, Martina Victoria; SCHLEMMER, Karl-Heinz; TERSTEEGEN, Adrian; BUCHMUeLLER, Anja; GERDES, Christoph; SCHAeFER, Martina; TELLER, Henrik; JIMENEZ NUNEZ, Eloisa; SCHIROK, Hartmut; KLAR, Juergen; (66 pag.)US2016/272637; (2016); A1;,
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem