Hydrochloric Acid → (+/-)-(E)-3-{3,4-dihydro-4-oxo-spiro[2H-(1,3)-benzoxazine-2,3'-piperidin]-6-yl}-acrylic acid methyl ester

Participants

Role	Name	HCID	Charge
Reactant	Hydrochloric Acid	HCID 313	—
Reactant	(E)-3-[4-oxo-spiro(chromane-2,3'-azetidine)-6-yl]-acrylic acid methyl ester	HCID 67071396	—
Reactant	(+/-)-(E)-3-{1'-tert-butoxycarbonyl-3,4-dihydro-4-oxo-spiro[2H-(1,3)-benzoxazine-2,3'-piperidin]-6-yl}-acrylic acid methyl ester	HCID 67071413	—
Solvent	Dichloromethane	HCID 6344	—
Solvent	1,4-Dioxane	HCID 31275	—
Product	(+/-)-(E)-3-{3,4-dihydro-4-oxo-spiro[2H-(1,3)-benzoxazine-2,3'-piperidin]-6-yl}-acrylic acid methyl ester	HCID 67071418	94.6%

Reaction Steps

(±)-(E)-3-{1′-Tert-butoxycarbonyl-3,4-dihydro-4-oxo-spiro[2H-(1,3)-benzoxazine-2,3′-piperidin]-6-yl}-acrylic acid methyl ester (1.90 g, 4.72 mmol) in DCM (33 ml) was treated with 4 M HCl in dioxane (5.90 ml) as described for Intermediate 4, Step C, giving (±)-(E)-3-{3,4-dihydro-4-oxo-spiro[2H-(1,3)-benzoxazine-2,3′-piperidin]-6-yl}-acrylic acid methyl ester (1.35 g, hydrochloride salt) as a light brown solid.

Provenance & Evidence

DOI	10.6084/m9.figshare.5104873.v1
Patent number	US08980877B2
Source dataset	uspto-grants-2015_03
ORD ID	ord-73d00993994d4abbbeaaf5b4e50850b9
Source note	uspto-grants-2015_03