Synthesis of the Bicyclic Secondary Amines via Dimethylaminomethylene Ketones from 3-Pyrrolidone and 4-Piperidone

Synthesis and antiproliferative activity of 3-(substituted)-4,5,6,7-tetrahydro-6-(substituted)-1H-pyrazolo[3,4-c]pyridine derivatives

“…Purification of the compound 3 required purification by using column chromatography. The overall yield obtained by this method is greater than earlier reports [13]. 4,5,6,7-Tetrahydro-1H-pyrazolo [4,3-c]pyridine (3) is reacted with di-tert-butyl dicarbonate (Boc anhydride) using triethylamine as base to obtain di-tert-butyl-4,5-di hydro-7H-pyrazolo [3,4-c]pyridine-1,6-dicarboxylate (4) with yield 91%.…”

“…The obtained crude material was purified by silica gel (100-200 mesh) column chromatography by using 10-40% ethyl acetate:hexane (v:v, 10-40:90-60). The obtained compound was washed with diethyl ether (100 mL) to obtain compound 3 [13]. …”

“…1 H NMR (400 MHz, DMSO-d6, δ, ppm): 1.56 (s, 18H, N-(t-Bu)2), 2.21 (d, 2H, J = 6.2 Hz, CH2), 2.79 (m, 2H, CH2), 3.83 (s, 2H, N-CH2), 7.31 (s, 1H, Ar-H). 13 …”

“…The 1 H NMR spectra were recorded on Varian NMR (400 MHz) spectrometer. The 13 C NMR spectra were recorded on Varian NMR (100 MHz) spectrometer. …”

Regioselective synthesis of pyrazoles fused with heteroaliphatic amines at the [3,4-c] edges

“…[4][5][6][7][8][9][10][11][12] The major drawback of this approach relates to regioselectivity issues when a substituent is needed at one of the pyrazole ring nitrogen atoms. 4,6,11 In this work, we report an alternative and regioselective approach to derivatives of 1, 4 and 5, involving annulation of the heteroaliphatic ring to the corresponding polysubstituted pyrazole derivative 6, from common, readily available starting materials (Nsubstituted hydrazine, chloroacetone and potassium phthalimide) (Scheme 2).…”