2-Butenal, 2-chloro- (9CI) 2-Chloro-2-butenal 2-Chlorocrotonaldehyde 3-01-00-02981 (Beilstein Handbook Reference) 53175-28-3 BRN 1698775 CCRIS 6867 Crotonaldehyde, 2-chloro- EINECS 258-412-3 alpha-Chlorocrotonaldehyde