4-BROMO-1-METHYL-1 H-PYRAZOLE-3-CARBOXYLIC ACID M ETHYL ESTER

to a mixture of methyl 4-bromo-1H-pyrazole-3-carboxylate (15.0 g, 73.2 mmol, ) andCs2CO3 (59.6 g, 182.9 mmol) in DMF(150 ml) was added mel (14.7 ml, 236.0 mmol) drop-wise at 0°c under N2. The mixture was stirred at 25 °C for 16 hours. The reaction mixture was filtered, the cake washed with ethyl acetate (200 ml x 2). The filtrate was washed with water (70 ml x 4) and the aqueous phase extracted with ethyl acetate (150 ml). The combined organic extracts were dried over Na2SO4, filtered and concentrated to dryness under reduced pressure to dryness. The crude product which was purified by fcc (gradient eluent: petroleum ether/ethyl acetate from 100/0 to 50/50) to afford the title compound 240a (8.3 g, yield 51.8percent) as a white solid and the title compound 240b (7.0 g, yield 43.7percent) as white solid. Compound 240a: 1H NMR (400mhz, CDCl3): δ 7.48 (s, 1h), 4.15 (s, 3h), 3.93 (s, 3h). MS (ESI) m/z (M+H)+ 219.0.

Molecular Weight:219.04
XLogP3:1.1
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:2
Exact Mass:217.96909
Monoisotopic Mass:217.96909
Topological Polar Surface Area:44.1
Heavy Atom Count:11
Complexity:165
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes