Cyclopropylmethyl bromide-d4 is the deuterium labeled Cyclopropylmethyl bromide (HY-Y1100). Cyclopropylmethyl bromide is an intermediate. Cyclopropylmethyl bromide can be used in the preparation of Firocoxib (HY-14670). Firocoxib (ML 1785713) is a potent, selective, orally active COX-2 inhibitor[1][2].