Terephthalic Acid → HCID 54016886, compound
Reaction equation
[C:1]([OH:12])(=[O:11])[C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][CH:3]=1.[N+](=C)=[N-]>>[C:1]([O:12][C:5]([CH3:6])=[CH2:4])(=[O:11])[C:2]1[CH:10]=[CH:9][C:5]([C:6]([O:8][C:2]([CH3:3])=[CH2:1])=[O:7])=[CH:4][CH:3]=1Participants
Procedure
The reaction described in Example 3 was repeated using 27.0 gm (0.162 moles) of terephthalic acid instead of azelaic acid. Infrared analysis of an aliquot of the product showed several materials present. Methylation of a representative portion of the product with diazomethane and analysis of the methylated product by GLC showed the product to be predominantly the half-ester with a smaller amount of the diisopropenyl ester. We anticipate that higher yields of diisopropenyl terephthalate can be obtained if the rate of reaction is increased by conducting it at higher temperatures and pressures. Pure diisopropenyl terephthalate was obtained by passing an aliquot of the above mixed reaction products through a short plug of Florisil (a magnesium silicate) and eluting with petroleum ether. The product crystallized in rhombic shaped plates from petroleum ether, m.p. 72°-73.5° C. Carbon and hydrogen analysis: calculated % C 68.29, % H 5.96; found % C 69.05, % H 5.58. Infrared examination of the crystals in carbon disulphide solution shows band maxima at 1737, 1263, 1210, 1110, 1092, 1017, 867, and 720 cm-1. NMR analysis in deuterochloroform shows absence of the ##STR1## proton signal in the chromatographed, recrystallized sample. The mass spectrum pattern of the unpurified product, m/e 189(100%), 161(50%), 132(10%), is indicative of the diisopropenyl ester. Reactants and products for this example are shown in Table I.
Sources & evidence
- ORD record
- ord-bb760167de35493d869e7ddbdabae6a2
- Source dataset
- uspto-grants-1981_04
- Patent number
- US04262137
Reaction notes
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