Reaction #1540

Reaction equation

benzamidine hydrochloride hydrate

sodium acetate

ethyl 3,3-diethoxyacrylate

DMSO

→

6-ethoxy-2-phenyl-4(3H)-pyrimidinone

Yield 57.0%

Solvents

NaOH

Conditions

Workup

1. 1
   TemperatureThe mixture was cooled
2. 2
   Washwashed with two 100 mL portions of ether
3. 3
   Filtrationthe precipitate was collected by filtration
4. 4
   Otherdried under vacuum at 50° C.

Procedure

A mixture of 3.14 g (20.0 mmol) of benzamidine hydrochloride hydrate, 1.65 g (20.1 mmol) of powdered anhydrous sodium acetate, 4.17 g (22.2 mmol) of ethyl 3,3-diethoxyacrylate and 10 mL of DMSO was heated at 120° C. for 8 h. The mixture was cooled, diluted with 50 mL of 5% aqueous NaOH and washed with two 100 mL portions of ether. The aqueous layer was acidified with concentrated hydrochloric acid and the precipitate was collected by filtration and dried under vacuum at 50° C. to furnish 2.28 g (57%) of crude 6-ethoxy-2-phenyl-4(3H)-pyrimidinone as a yellow solid 1 H-NMR (d6-DMSO) δ 1.35(3H,t), 4.33(2H,q), 5.60(1H,s), 7.50(3H,m), 8.2(2H,m).

Source