3-chloro-2,4,5-trifluoro-Benzenepropanoic acid ethyl ester synthesis

Yield:295330-86-8 98%

Reaction Conditions:

with triethylamine in dichloromethane at 0 - 20; for 1 h;Inert atmosphere;

Steps:

1 Step 1 - Tert-butyl 4-(3-methylsulfonyloxypropyl)piperazine-1-carboxylate

To a solution of tert-butyl 4-(3-hydroxypropyl)piperazine-1-carboxylate (1.00 g, 4.09 mmol, CAS 132710-90-8) and TEA (621 mg, 6.14 mmol) in DCM (15 mL) was added MsCl (562 mg, 4.91 mmol) at 0 °C. The reaction mixture was stirred at 0~ 20 °C for 1 hr. On completion, the reaction mixture was diluted with water (20 mL) and extracted with DCM (3 X 25 mL). The combined organic layers were washed with brine (3 X 30 mL), dried over Na2SO4, filtered and concentrated in vacuo to give the title compound (1.30 g, 98% yield) as yellow oil.¹H NMR (400 MHz, CDCl3) d 4.33 (t, J = 6.4 Hz, 2H), 3.55 - 3.40 (m, 4H), 3.03 (s, 3H), 2.61 - 2.37 (m, 6H), 2.05 - 1.93 (m, 2H), 1.46 (s, 9H).

References:

WO2020/113233,2020,A1 Location in patent:Paragraph 00962; 003314-003316