Reaction #1726723

Reaction equation

TFA

2-hydroxy-5-(morpholin-4-yl)benzamide

1-Boc-4-piperidone

morpholine

→

1′-(tert-butyloxycarbonyl)-6-(morpholin-4-yl)spiro[1,3-benzoxazine-2,4′-piperidine]-4(3H)-one

Yield 57.0%

Solvents

dichloromethane

MeOH

Conditions

Workup

1. 1
   Temperatureis refluxed for 6 days
2. 2
   OtherRemoval of solvent
3. 3
   Otherby rotoevaporation and purification by preparative TLC

Procedure

A mixture of 50 mg (0.23 mmol) of 2-hydroxy-5-(morpholin-4-yl)benzamide, 59 mg (0.30 mmol) of 1-Boc-4-piperidone, and 40 μL of morpholine in 3 mL of MeOH is refluxed for 6 days. Removal of solvent by rotoevaporation and purification by preparative TLC gives 53 mg (0.13 mmol, 57% yield) of 1′-(tert-butyloxycarbonyl)-6-(morpholin-4-yl)spiro[1,3-benzoxazine-2,4′-piperidine]-4(3H)-one which on treatment with 40% TFA in dichloromethane at room temperature for 2 hr. gives the bis-TFA salt of 6-(morpholin-4-yl)spiro[1,3-benzoxazine-2,4′-piperidine]-4(3H)-one in quantitative yield.

Source