Reference of 31037-02-2, As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 31037-02-2 name is Ethyl 5-amino-1-methyl-1H-pyrazole-4-carboxylate, This compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below.
EXAMPLE IX.5 This Example illustrates a preparation of ethyl 5-(4,4-difluorobut-3-enylthio)-1-methylpyrazol-4-yl carboxylate (Compound IX.34). Bis-(4,4-difluorobut-3-enyl)disulfide (2.90 g) and tert.butyl nitrite (1.22 g) in acetonitrile (40 cm3) were heated to 60 C. under an atmosphere of nitrogen. To the stirred solution was added dropwise ethyl 5-amino-1-methylpyrazol-4-yl carboxylate (1.00 g) in acetonitrile (10 cm3). On complete addition the reaction solution was heated for 2 hours at 60 C., evaporated under reduced pressure and fractionated by chromatography (silica; hexane:diethyl ether, 5:1 by volume) to give Compound IX.34 (yield 42%). M+ =276; 1 H NMR: delta 1.38(3H,t); 2.20(2H,m); 3.05(2H,t); 3.97(3H,s); 4.25(1H,m); 4.34(2H,q); 7.98(1H,s); (oil).
At the same time, in my other blogs, there are other synthetic methods of this type of compound, Ethyl 5-amino-1-methyl-1H-pyrazole-4-carboxylate, and friends who are interested can also refer to it.
Reference:
Patent; Zeneca Limited; US5705516; (1998); A;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics