Boron tribromide → 9-hydroxy-4-(4-hydroxyphenyl)pyrrolo[3,4-c]carbazole-1,3(2H,6H)-dione

Participants

Role	Name	HCID	Charge
Reactant	Boron tribromide	HCID 25134	—
Reactant	Benzyl 9-methoxy-1,3-dioxo-1,2,3,3a,4,5,6,10c-octahydropyrrolo[3,4-c]carbazole-4-carboxylate	HCID 11843004	—
Reactant	9-hydroxy-4-(4-methoxyphenyl)pyrrolo[3,4-c]carbazole-1,3(2H,6H)-dione	HCID 11843288	—
Product	9-hydroxy-4-(4-hydroxyphenyl)pyrrolo[3,4-c]carbazole-1,3(2H,6H)-dione	HCID 10405212	92%

Reaction Steps

The reaction of 9-hydroxy-4-(4-methoxyphenyl)pyrrolo[3,4-c]carbazole-1,3(2H,6H)-dione prepared as decribed in example 34 with BBr3 using the procedure described in example 80 of Scheme 2 gave 9-Hydroxy-4-(4-hydroxyphenyl)pyrrolo[3,4-c]carbazole-1,3(2H,6H)-dione (24) (I, Ar=4-hydroxyphenyl) in a 92% yield; mp 230° C. (dec). 1H NMR δ [(CD3)2SO] 11.67 (s, 1H), 10.96 (s, 1H), 9.59 (s, 1H), 9.22 (s, 1H), 8.32 (d, J=2.4 Hz, 1H), 7.51 (s, 1H), 7.43 (d, J=8.7 Hz, 1H), 7.41 (d, J=8.6 Hz, 2H), 7.04 (dd, J=8.7, 2.4 Hz, 1H), 6.84 (d, J=8.6 Hz, 2H). FABMS found [M+H]+: 345.0875. C20H13N2O4 requires 345.0875.

Provenance & Evidence

DOI	10.6084/m9.figshare.5104873.v1
Patent number	US07094798B1
Source dataset	uspto-grants-2006_08
ORD ID	ord-0d320a739e89434084f2648f376f549b
Source note	uspto-grants-2006_08