L- methyl-3-ethynylpyrazole

The acidity of 4-acetylenenylpyrazoles increases by 0.3-0.7 log units on introducing CH2NH2 group into position 5 of the ring. Chlorine atoms have the greatest acidifying effect. Chlorine atom in position 5 increases the acidity of l-methyl-3-ethynylpyrazole. 

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