Reaktion #969901

Reaktionsgleichung

HCl

NaHCO3

formaldehyde

product

8-[4-(benzyloxy)phenoxy]-2,3,4,5-tetrahydro-1,2,5-benzothiadiazepine 1,1-dioxide

bromocresol green

sodium cyanoborohydride

→

8-[4-(benzyloxy)phenoxy]-5-methyl-2,3,4,5-tetrahydro-1,2,5-benzothiadiazepine 1,1-dioxide

Lösungsmittel

dioxane

acetonitrile

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGThe reaction mixture is stirred overnight at ambient temperature
2. 2
   Filtrationa precipitate forms, which is filtered off
3. 3
   SonstigePurification of the title product
4. 4
   Wascheneluting with a mixture of dichloromethane/ethyl acetate 96/4

Vorschrift

Aqueous formaldehyde 37% (12.6 mmol) is added to a suspension of the product of Example 8 (2.52 mmol) in 10 ml of acetonitrile. The suspension is stirred for 1 hour at ambient temperature. A spatula tip of bromocresol green and sodium cyanoborohydride (7.56 mmol) are added in succession. The reaction mixture is brought to acid pH by adding 4N HCl solution in dioxane. The reaction mixture is stirred overnight at ambient temperature and is then neutralised by addition of 10% NaHCO3 solution. After diluting the reaction mixture with water, a precipitate forms, which is filtered off. Purification of the title product is carried out by chromatography on silica, eluting with a mixture of dichloromethane/ethyl acetate 96/4.

Quelle