IMidodicarbonic acid, 2-[3-Methoxy-5-(4,4,5,5-tetraMethyl-1,3,2-dioxaborolan-2-yl)-2-pyrazinyl]-, 1,3-bis(1,1-diMethylethyl) ester synthesis

Yield:1111638-28-8 100%

Reaction Conditions:

with potassium acetate;(1,1'-bis(diphenylphosphino)ferrocene)palladium(II) dichloride in toluene at 50; for 96 h;

Steps:

B-79

Preparation of 1-(tert-butoxycarbonyl)-2,3-dihydro-1H-pyrrolo[2,3-b]pyridin-5-ylboronic acid (B-12- 3) B-12-2 ^{B"1 2}-³To a mixture of tert-butyl 5-bromo-2,3-dihydropyrrolo[2,3-b]pyridine-1-carboxylate (B-12-2) (725 mg, 2.42 mMoles) and bis(pinacolato) diboron (894 mg, 3.52 mMoles) in 20 ml DMF were added potassium acetate (691 mg, 7.04 mMoles) and [1 ,1-Bis(diphenylphosphino)-ferrocene]dichloropalladium (II) dichloromethane (1 :1) complex (34.3 mg, 0.0469 mMoles). The mixture was heated in 100⁰C microwave reactor for 60 min. LCMS indicated reaction was complete. RXN was filtered and the filtrate was concentrated to dryness under high vacuum. The residual was partitioned between EtOAc and saturated aqueous NaCI. The aqueous layer was extracted with EtOAc (3x40 ml_). The combined organic layers were dried over sodium sulfate, filtered and concentrated under reduced pressure. The residue was chromatographed on a 25 g silica gel cartridge with 1-4% MeOH in DCM as solvent. The crude product and was used as is in the next step.

References:

WO2009/16460,2009,A2 Location in patent:Page/Page column 93-94