22919-28-4

Basic information

• Product Name: 1,2-dihydrophthalic acid
• Synonyms: 1,2-dihydrophthalic acid;NSC131336;3,5-Cyclohexadiene-1,2-dicarboxylic acid;Cyclohexa-3,5-diene-1,2-dicarboxylic acid
• CAS NO: 22919-28-4
• Molecular Formula: C₈H₈O₄
• Molecular Weight: 168.14672
• EINECS: 245-326-6
• Mol File: 22919-28-4.mol

Chemical Properties

• Melting Point: 209-210 °C
• Boiling Point: 413°Cat760mmHg
• Flash Point: 217.7°C
• Appearance: /
• Density: 1.43g/cm³
• Vapor Pressure: 5.61E-08mmHg at 25°C
• Refractive Index: 1.579
• PKA: 3.37±0.40(Predicted)
• CAS DataBase Reference: 1,2-dihydrophthalic acid(CAS DataBase Reference)
• NIST Chemistry Reference: 1,2-dihydrophthalic acid(22919-28-4)
• EPA Substance Registry System: 1,2-dihydrophthalic acid(22919-28-4)

Safety Data

• Hazardous Substances Data: 22919-28-4(Hazardous Substances Data)

Usage

Synthesis Reference(s)

Tetrahedron Letters, 34, p. 2629, 1993 DOI: 10.1016/S0040-4039(00)77642-8

InChI:InChI=1/C8H8O4/c9-7(10)5-3-1-2-4-6(5)8(11)12/h1-6H,(H,9,10)(H,11,12)

Upstream product

• 88-99-3 benzene-1,2-dicarboxylic acid 
• 64-19-7 acetic acid 
• 64-17-5 ethanol 
• 7664-93-9 sulfuric acid 
• 7732-18-5 water 
• 85-44-9 phthalic anhydride 

Downstream Products

• 73473-80-0 1,2-Dihydrophthalyltosylat 
• 3097-60-7 bicyclo<2.2.0>hex-5-ene-2,3-dicarboxylic anhydride 
• 77803-99-7 t-2,t-3,c-4-Triacetoxy-r-1-cyclohexan-c-5,t-6-dicarbonsaeure-di-tert-butylester 
• 77803-99-7 t-2,t-3,c-4-Triacetoxy-r-1-cyclohexan-t-5,c-6-dicarbonsaeure-di-tert-butylester 
• 77804-00-3 (1R,2R,3R,4S,5R,6S)-3,4,5-Triacetoxy-6-[acetyl-(4-chloro-phenyl)-amino]-cyclohexane-1,2-dicarboxylic acid 
• 77804-00-3 (1S,2S,3R,4S,5R,6S)-3,4,5-Triacetoxy-6-[acetyl-(4-chloro-phenyl)-amino]-cyclohexane-1,2-dicarboxylic acid 
• 77803-98-6 c-6-Acetoxy-r-3-cyclohexen-c-4,t-5-dicarbonsaeure-di-tert-butylester 
• 77803-98-6 c-6-Acetoxy-r-3-cyclohexen-t-4,c-5-dicarbonsaeure-di-tert-butylester 
• 77803-95-3 r-1-Acetamido-c-2,c-3,c-4-trisacetoxycyclohexan-t-5,t-6-dicarbonsaeure-dimethylester 
• 77803-95-3 r-1-Acetamido-t-2,t-3,c-4-triacetoxy-t-5,t-6-dicarbonsaeure-dimethylester 
• 77803-95-3 r-1-Acetamido-c-2,t-3,c-4-trisacetoxycyclohexan-t-5,t-6-dicarbonsaeure-dimethylester 
• 77803-92-0 N-(p-Chlorphenyl)-1-oxa-3-azabicyclo<2.2.2>-5-octen-7-endo-8-exo-dicarbonsaeure-di-tert-butylester 
• 77803-92-0 N-(p-Chlorphenyl)-1-oxa-3-azabicyclo<2.2.2>-5-octen-7-exo-8-endo-dicarbonsaeure-di-tert-butylester 
• 77804-01-4 c-2,c-4-Diacetoxy-t-3-brom-r-1-(p-chloranilino)cyclohexan-t-5,c-6-dicarbonsaeure-di-tert-butylester 

Relevant articles and documents

Unveiling a Masked Polymer of Dewar Benzene Reveals trans-Poly(acetylene)

A dibromo derivative of Dewar benzene, trans-5,6-dibromobicyclo[2.2.0]hex-1-ene, was polymerized using ring-opening metathesis polymerization (ROMP). The reaction proceeded in a controlled manner as changing the initial monomer-to-catalyst ratio afforded monodispersed polymers with tunable molecular weights and growing polymer chains were extended upon subsequent exposure to additional monomer. Treatment of the halogenated polymers with an alkyllithium reagent resulted in elimination followed by isomerization to afford trans-poly(acetylene). Based on a series of mechanistic and spectroscopic studies, the transformation was proposed to proceed through a cyclobutenyl intermediate that undergoes rearrangement. The methodology was found to be versatile as triblock copolymers containing the halogenated homopolymer were prepared and converted to their poly(acetylene)-containing derivatives. The polymers were characterized using gel permeation chromatography as well as a range of spectroscopic (NMR, FT-IR, UV-vis, and Raman) and analytical techniques.

Preparation method of bicyclo-tetracarboxylic dianhydride

The invention discloses a preparation method of bicyclo-tetracarboxylic dianhydride, and belongs to the field of a preparation method of fine chemicals. In the technical scheme, the preparation methodis mainly characterized in that with cheap phthalic acid being initial raw materials, 3,5-cyclopentadiene-1,2-dicarboxylic acid is generated through electrolytic reduction; then the 3,5- cyclopentadiene-1,2-dicarboxylic acid reacts with maleic anhydride, acetic anhydride or propionic anhydride is used as solvent and a dehydrating agent, and bicyclo-tetracarboxylic dianhydride is generated under 1,4-addition reaction and dehydrating ring-closure reaction. In the scheme, the preparation method has the advantages of being low in manufacturing cost, high in utilization rate of atoms, high in yield, mild in reaction condition, environmentally friendly and the like.

SYNTHESIS OF 1,2-DISUBSTITUTED BENZENES AND BIPHENYLS FROM PHTHALIC ACIDS THROUGH ELECTROREDUCTION FOLLOWED BY ELECTROCYCLIC REACTIONS WITH ALKYNES

Various substituted 1,2-dihydrophthalic acids were synthesized by electroreduction of phthalic acids in excellent yields.The electrocyclic reaction of 1,2-dihydrophthalic acids or the methyl ester with alkynes gave 1,2-disubstituted benzenes and biphenyls in good yields together with fumaric acid or methyl fumarate.

Direct spectroscopic study of unstable molecules with silicon-oxygen multiple bonds: Low temperature matrix stabilization of (CH3)2Si=O and (CD3)2Si=O in the gas phase

To continue the IR spectroscopic investigations of intermediates with doublebonded silicon, the silanones (CH3)2Si=O and (CD3)2Si=O have been generated by vacuum pyrolysis of the corresponding 6-oxa-3-silabicyclohexanes and of Diels-Alder adducts of silapyranes with maleic anhydride.The above silanones have first been stabilized from the gas phase in argon matrices at 12 K and studied by IR spectroscopy.Using the dependence of the spectra on temperature and pressure in the pyrolysis zone or in warming-up experiments (to 35-40 K) the following vibrational bands of silanones have been revealed: (CH3)2Si=O 1244, 1240, 1210, 822, 798, 770, 657 cm-1; (CD3)2Si=O 1215, 1032, 1007, 995, 712, 685, 674 cm-1.The limits of thermal ( 850 deg C) and kinetic (5 x 10E-4 torr) stability of dimethylsilanone were determined.By comparison of frequencies found with computed values the band 1210 cm-1 in (CH3)2Si=O (1215 cm-1 in (CD3)2Si=O) was assigned to a Si=O streching vibration.This frequency as well as the calculated force constant (8.32 mdyn/Angstroem) and order (1.45) of the Si=O bond are considered as evidence of significant double bonding in dimethylsilanone.