1,5-bis(4'-hydroxy-3'-methoxyphenyl)-1,4-pentadien-3-one (Gamavuton-0 or GVT-0) is one of the curcumin analog compounds that can be used as an anticancer. The prevalence of cancer in Indonesia shows a high value when compared with chronic obstructive pulmonary disease and asthma. Therefore, anticancer development is necessary. One of the anticancer development efforts is making anticancer compounds such as GVT-0. GVT-0 can be synthesized using vanillin and acetone through the Claisen-Schmidt condensation reaction. One of the factors that can affect the reaction speed is the heating time. The purpose of this study to determine the effect of heating time on GVT-0 produced. GVT-0 was synthesized using vanillin as much as 4,141 grams dissolved in ethanol and 1 ml of acidified acetone. The reaction is carried out with some variation of heating time at a regulated temperature. After the reaction is done then purification using recrystallization method. Based on the research data, linear regression analysis the relationship between time and percentage of GVT-0 formed yield regression equation y = 9,471x - 5,657 with value R2 = 0,987. The y value is the percentage of GVT-0 formed and the value of x is the required heating time for the reaction. Based on the regression equation, it can be predicted the time required to obtain 100% GVT-0 with reaction conditions that have been calculated. Based on the calculation using the regression equation, GVT-0 is predicted to be 100% at 11,2 hours.