Reaction #46308

Reaction equation

HCl

1-bromo-4-chlorobutane

6-(3-chloro-4-fluorobenzyl)-3,4-dihydroxy-N,N-dimethyl-5-oxo-5,6,7,8-tetrahydro-2,6-naphthyridine-1-carboxamide

magnesium methoxide

→

title compound

11-(3-Chloro-4-fluorobenzyl)-9-hydroxy-3,4,5,6,12,13-hexahydro-[1,4]oxazocino[3,4-a]-2,6-naphthyridine-1,8,10(11H)-trione

Solvents

DMSO

methanol

DMSO

Conditions

Workup

1. 1
   OtherMethanol was exhaustively removed under vacuum over 45 minutes
2. 2
   TemperatureThe reaction mixture was heated at 100° C. for 3 hrs
3. 3
   OtherThe solid precipitated
4. 4
   Filtrationwas filtered
5. 5
   workup.DISSOLUTIONdissolved in DMSO
6. 6
   Otherphase HPLC purification
7. 7
   OtherCollection and lyophization of appropriate fractions

Procedure

A mixture of 6-(3-chloro-4-fluorobenzyl)-3,4-dihydroxy-N,N-dimethyl-5-oxo-5,6,7,8-tetrahydro-2,6-naphthyridine-1-carboxamide (0.80 g, 2.19 mmol; Example 1, step 9) and magnesium methoxide in methanol (10.6 mL, 6-10% methanol solution available from Aldrich) in DMSO (22 mL) was heated at 60° C. for 30 minutes. Methanol was exhaustively removed under vacuum over 45 minutes. The residual DMSO solution was treated with 1-bromo-4-chlorobutane (1.80 g, 10.50 mmol) and stirred at 60° C. under an atmosphere of nitrogen overnight. The reaction mixture was heated at 100° C. for 3 hrs. The reaction mixture was treated with dilute HCl. The solid precipitated was filtered, dissolved in DMSO, and subjected to reverse phase HPLC purification. Collection and lyophization of appropriate fractions provided the title compound.

Source