The invention provides an amide compound with the formula a and a preparation method thereof. The compound with the formula a (shown in the Specification, and R1 is defined in the specification), is a novel compound, and is a relative matter generated from the synthesis of a compound c used for vein embolism related diseases, and can be used as the reference substance or standard substance of the relative matters in the quality control of the compound c, thereby facilitating the pharmaceutical quality control of the compound c.