Stir tomatoes and chicken brother together in a large saucepan; bring to a boil, reduce heat to medium-low, and cook at a simmer until slightly reduced, about 10 minutes.
Stir basil and sugar into the tomato mixture; reduce heat to low and continue cooking until the basil is wilted, about 5 minutes.
Stir cream into the tomato mixture; add butter and continue cooking, stirring occasionally, until the butter is completely melted, 5 to 7 minutes more.
