In the second step, 4-coumarate : CoA ligase ( 4CL ) converts cinnamic acid to cinnamoyl-CoA by an acid-thiol ligation . 4CL effects this reaction in two steps . 4CL forms a hydroxycinnamate-AMP anhydride, followed by a nucleophile attack on the carbonyl of the acyl adenylate.
42.
"' Phenylpropiolic acid "', C 6 H 5 CCCO 2 H, formed by the action of alcoholic potash on cinnamic acid dibromide, C 6 H 5 CHBrCHBrCO 2 H, crystallizes in long needles or prisms which melt at 136 137 �C . When heated with water to 120 �C, it yields phenylacetylene ( C 6 H 5 CCH ).
43.
Also, I see several sources that call # 1 in your synthesis " Hydrocinnamic acid " which would indicate that it is more common to work your reaction mechanism backwards; that is to hydrogenate cinnamic acid to make # 1 rather that to dehydrogenate # 1 to get # 2 . . .-- 32 " "'06 : 37, 4 January 2010 ( UTC)
44.
Chromic acid oxidizes it to benzoic acid; zinc and acetic acid reduce it to cinnamic acid, C 6 H 5 CH = CHCO 2 H, whilst sodium amalgam reduces it to hydrocinnamic acid, C 6 H 5 CH 2 CH 2 CO 2 H . Ortho-nitrophenylpropiolic acid, NO 2 C 6 H 4 CCCO 2 H, prepared by the action of alcoholic potash on ortho-nitrocinnamic acid dibromide, crystallizes in needles which decompose when heated to 155 156 �C . It is readily converted into indigo.
45.
William Perkin continued active research in organic chemistry for the rest of his life : he discovered and marketed other synthetic dyes, including " Britannia Violet " and " Perkin's Green "; he discovered ways to make coumarin, one of the first synthetic perfume raw materials, and cinnamic acid . ( The reaction used to make the latter became known as the Perkin reaction . ) Local lore has it that the colour of the nearby Grand Union Canal changed from week to week depending on the activity at Perkin's Greenford dyeworks.
