Ammonium Hydroxide → HCID 58932529, compound

Participants

Reaction Conditions

Reaction Steps

To a cold solution of 8′-methoxy-3′,4′-dihydro-2′H-spiro[1,3-dioxane-2,10′pyrimido[1,2-a]indole] (0.723 g, 2.63 mmol) in anhyd. CH2Cl2 (26.4 mL) was added neat boron tribromide (0.80 mL, 8.43 mmol, 3.2 eq) drop-wise via syringe pump over a period of 55 min with cooling to −75° C. in a dry ice/iPrOH bath. The reaction was kept at about −18° C. for 13 hr then poured onto ice and neutralized to pH 7 with concentrated NH4OH keeping the reaction temperature <5° C. The reaction mixture was extracted with EtOAc. The combined organic extracts were dried over Na2SO4 and concentrated. The crude product was combined with the product (0.11 g) from a previous run and triturated with warm EtOAc and filtered to give the title compound as a dark red solid (0.178 g, 33% yield). NMR (300 Mz, DMSO-d6): consistent. MS: (APCI+) 203 [M+H].

Provenance & Evidence