Cesium carbonate → Ethyl 5-(1-phenylvinyl)thiazolo[5,4-b]pyridine-2-carboxylate

HRID 1177400Notes

Reaction equation

Cl[C:2]1[N:7]=[C:6]2[S:8][C:9]([C:11]([O:13][CH2:14][CH3:15])=[O:12])=[N:10][C:5]2=[CH:4][CH:3]=1.[C:16]1([C:22](B(O)O)=[CH2:23])[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1.C(=O)([O-])[O-].[Cs+].[Cs+].C1(P(C2CCCCC2)C2C=CC=CC=2C2C(OC)=CC=CC=2OC)CCCCC1>C1(C)C=CC=CC=1.CC(O)=O.CC(O)=O.[Pd]>[C:16]1([C:22]([C:2]2[N:7]=[C:6]3[S:8][C:9]([C:11]([O:13][CH2:14][CH3:15])=[O:12])=[N:10][C:5]3=[CH:4][CH:3]=2)=[CH2:23])[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1

Participants

Conditions

Temperature: 90 °C

Procedure

A mixture of ethyl 5-chlorothiazolo[5,4-b]pyridine-2-carboxylate (500 mg, 2.06 mmol), 1-phenylvinylboronic acid (366 mg, 2.47 mmol), Pd(Oac)2 (18.5 mg, 82.4 μmol), cesium carbonate (1.343 g, 4.12 mmol), and 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (S-Phos; 33.8 mg, 82.4 μmol) in toluene (10.0 mL) was sparged with argon, then heated at 90° C. for 21.5 h. The resulting brown solution was diluted with dichloromethane (30 mL) and filtered through a pad of silica gel (washing pad with ethyl acetate (3×30 mL)). The filtrate was concentrated in vacuo, and the residue was purified via column chromatography (silica gel, 0-70% EtOAc/hexanes) to afford ethyl 5-(1-phenylvinyl)thiazolo[5,4-b]pyridine-2-carboxylate as a light yellow solid. MS (ESI) m/z: Calculated: 310.1; Observed: 311.1 (M++1).

Workup

customwas sparged with argon
additionThe resulting brown solution was diluted with dichloromethane (30 mL)
filtrationfiltered through a pad of silica gel (washing pad with ethyl acetate (3×30 mL))
concentrationThe filtrate was concentrated in vacuo
customthe residue was purified via column chromatography (silica gel, 0-70% EtOAc/hexanes)

Sources & evidence

ORD record: ord-9d7e54b8b43b4fa29eb1955ddf6891cc
Source dataset: uspto-grants-2010_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07842685B2

Reaction notes

Loading…