Preheat oven to 350 degrees. Melt butter and chocolate together in a double boiler and set aside. Meanwhile mix sugar, salt, and flour, in a separate bowl. Stir in syrup and eggs. Add melted butter and chocolate. Add vanilla and pecans and blend all ingredients. Pour into an unbaked pie shell. You might want to use a quiche pan for serving ease. Bake one hour or until firm to the touch. Cool and serve.