Sodium Carbonate → Methyl 5-chloro-4-(1-ethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate

Participants

Role	Name	HCID	Charge
Reactant	Sodium Carbonate	HCID 10340	—
Reactant	1-Ethylpyrazole-5-boronic acid, pinacol ester	HCID 53217252	—
Reactant	Methyl 4-bromo-5-chlorothiophene-2-carboxylate	HCID 57826388	—
Catalyst	Bis(cyclopenta-1,4-dien-1-yl(diphenyl)phosphane);dichloropalladium;iron(2+)	HCID 178418228	—
Solvent	Tetrahydrofuran	HCID 8028	—
Product	Methyl 5-chloro-4-(1-ethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate	HCID 57826590	85.9%

Reaction Conditions

Temperature	80 °C

Reaction Steps

To a solution of methyl 4-bromo-5-chloro-2-thiophenecarboxylate (300 mg, 1.17 mmol) in THF (2 mL) was added Na2CO3 (2M, 1.76 mL, 3.52 mmol), Pd(dppf)Cl2 (86, 0.117 mmol) and 1-ethyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (313 mg, 1.41 mmol). The reaction mixture was heated to 80° C. in a sealed tube under N2. After 2 h, the reaction mixture was concentrated under vacuum and purified on silica (EtOAc/Hex, 20-50%) to afford the title compound (0.272 g, 82%) as a light yellow syrup: LC-MS (ES) m/z=271 (M+H)+.

Provenance & Evidence

DOI	10.6084/m9.figshare.5104873.v1
Patent number	US08946278B2
Source dataset	uspto-grants-2015_02
ORD ID	ord-1796fde5ce384de99aac510303bab7c9
Source note	uspto-grants-2015_02