Dimethyl Sulfoxide → HCID 14867576, compound

Participants

Reaction Steps

A mixture of 100 g (2.87) mmole) of 6-cyclohexyl-4,7-dihydro-2-phenyl-5H-pyrazolo[1,5-a]pyrrolo[3,4-d]pyrimidine-5,8-dione (see preparation 1), 0.82 ml. (5.7 mmoles), of ethyl 4-bromobutyrate and 0.41 g., 3.0 mmole of potassium carbonate in 11 ml. of -dimethyl-sulfoxide (DMSO) was stirred at 50° C. for 16.5 hours. Then 35 ml. of water was added and the mixture was suction filtered. The collected solid was washed with more water and air dried. The crude solid was recrystallized from 95% ethanol (100 ml), reflux cooled to room temperature, affording 1.11 g (84% yield) of the titled compound as very fine white needles, m.p. 195°-196° C. 1H NMR (CDCl3, δ) 8.06 (d, 2H, phenyl-H (ortho), 7.45 (m, 3H, phenyl-H), 6.70 (s, 1H, pyrazole-H, 4.74 (t, 2H, J=Hz, 4-NCH 2), 4.37 (s, 2H, lactam CH2), 4.16 (q, 2H, J=7 Hz, OCH2), 4.15 (m, 1H, 6-NCH), 2.49 (t, 2H, CH2CO2C2H5), 2.23 (m, 2H, CH2), 1.15-1.95 (m, 10H, cyclohexyl CH2), 1.26 (t, 3H, J"7 Hz, CH3.

Provenance & Evidence