3.5- Dichlorophthalic anhydride

Dichlorophthalic anhydride [4466-59-5] M 189-191 , 191-191.5 , b 339 . Boil in xylene (allowing any vapours which would contain H O to be removed, e.g. Dean and Stark trap), which causes the acid to dehydrate to the anhydride and cool. Recryst from xylene [Villiger Chem Ber 42 3539 1909 Fedoorow Izv Akad Nauk SSSR Otd Khim Nauk 397 1948, Chem Abstr 1585 1948]. 

Dichlorophthalic anhydride Carbazic acid, tert-butyl ester... 

The solution of 3,6-dichlorophthalic anhydride in 300 ml of N,N-dimethylformamide are heated to the boiling point over 15 min with t-butylcarbazate. Subsequent to evaporation of the solvent, N-(t-butyloxycarbonylamino)-3,6-dichlorophthalimide is obtained from ethanol. 

The reagent is prepared by reaction of tris(4-aminophenyl)methanol (pararosaniline) with 4,5-dichlorophthalic anhydride followed by bromination with acetyl bromide. 

The desired molecular tool, CSDP acid (-)-l, was synthesized by reacting (lS,2R,4R)-(-)-2,10-camphorsultam anion with 4,5-dichlorophthalic anhydride [(-)-l, mp 221 °C from EtOH [a]D ° -101.1 (c 1.375, MeOH) Fig. 9.2]. This carboxylic acid was condensed with alcohol in the presence of 1,3-dicyclohexylcarbodiimide (DCC) and 4-dimethylaminopyridine (DMAP) [17]. 

Dichlorophthalic anhydride, TEA, and CICH2CH2CI, followed by ring closure... 

Dichlorophthalic anhydride 2,2-Dichloropropionic acid cis-l,3-Dichloropropylene trans-1,3 -Dichloropropylene... 

Dichlorophthalic acid [56962-08-4] M 235.0, m 200 (dec to anhydride), pKggtd) 2 2, P st(2) 4.7. Crystd from water. Can be purified by converting to the anhydride, reacting with boiling EtOH to form the monoethyl ester (m 133-134°) and hydrolysing back to the diacid... 

We attempted to solve this kinetically insoluble problem by using solvent effect. For this purpose various tertiary amines have been reacted with cyclic anhydrides in aprotic media [38,48]. (amines dimethylformamide, N,N -dimethylaniline, triethyl-amine, 1,4-diaza-[2,2,2] bicyclo-octane and pyridine anthydrides tetrachloroph-thalic, 3,6-dichlorophthalic, 3-nitrophthalic, 4-nitrophthalic, 3,5-dinitrophthalic, phthalic and 1,8-naphthalic). 

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