1-Ethynyl-4-methylbenzene 4-05-00-01531 (Beilstein Handbook Reference) 4-Methylphenylacetylene 766-97-2 BRN 0969653 Benzene, 1-ethynyl-4-methyl- (9CI) TOLUENE, p-ETHYNYL- p-Ethynyltoluene p-Methylphenylacetylene p-Tolylacetylene