Mucochloric acid

With the saturated analogs, i.e. succinic anhydride and its derivatives, pyridazines are formed in only a few cases. The reaction has been applied to the preparation of perhydro-pyridazines and their 3,6-diones (68MI21200, 70JOC1468). For the synthesis of 4,5-dihalopyridazinones, /3-formylacrylic acids, for example mucochloric acid, are useful syn-thons (Scheme 80). 

Mucochloric acid (2,3-dichloro-4-oxo-2-butenoic acid) [87-56-9] M 169.0, m 124-126, pK 4.20. Crystd twice from water (charcoal). 

Chloro-2-hydrazinoquinoxaline (254) with mucochloric acid (255) gave 6-chloro-2-(4,5-dichloro-6-oxo-1,6-dihydropyridazin-1 -yl)quinoxaline (256) (AcOH, reflux, 5.5 h 87% analogs likewise). ... 

Mucochloric acid (open) Fig. 4 Molecular structures of MX analogs... 

Thioureas react readily with /3-diketones, and reactions with thioureas in many cases give higher yields than ureas in pyrimidine cyclizations. d -Alkylisothioureas are frequently used instead of thioureas, as demonstrated by the reaction of A-methylthiuronium sulfate 654 with mucochloric acid (2,3-dichloromalealdehydic acid) 653 which represents an example of reaction with a masked ketoaldehyde where the ketone is protected as a vinyl chloride <2002SC153>. 

OH hydroxy or tautomeric oxo form. b Mucochloric acid (decarboxylation). c R-7 = pyridyl, thienyl. d Meldrum s acid derivative. 

Practical grade mucochloric acid obtained from Aldrich Chemical Company, Inc. (mp 125-128°C) was used. Unless otherwise stated, all reagents and solvents were of commercial grade. The checkers used mucochloric acid obtained from Eastman Organic Chemicals. 

Dichloro-5-isopropoxy-2(5H)-furanone 2(5H)-Furanone. 3,4-dichloro-5-isopropoxy- (8) 2(5H)-Furanone, 3,4-dichloro-5-(1-methylethoxy)- (9) (29814-12-8) Mucochloric acid Malealdehydic acid, dichloro- (8) 2-Butenoic acid, 2,3-dictiloro-4-oxo-, (2)- (9) (87-56-9)... 

The kinetics and mechanism of the reactions of trialkyl phosphites with mucochloric acid (dichloroaldehydoacrylic acid) have been studied.6 Cine-substitution products are formed in reactions of 2,5- and 2,6-dichloro-l,4-benzoquinone with pyrrolidine.7... 

A kinetic study of the reaction of trialkylphosphites with mucochloric acid has established that this unusual variant of the Arbuzov reaction proceeds with elimination of both alkyl halide and HC1 at the second stage.87... 

Yinylogous enamine dyes are obtained by reaction of aromatic amines with mucochloric acid (2,3-dichloro-4-oxo-2-butanoic acid), followed by condensation with quaternary quinaldine. After methylation of the enamine nitrogen atom with dimethyl sulfate, the dye 5 is obtained, which dyes bleached sulfite pulp red [15]. 

Methyl thiophenol fensulfothion, sulfoprofos Methyl thiopseudo urea guazatine, hexazinone 4 Methyl thiosemi carbazide thiazafluron Methyl thio urea tebuthiuron, thiazafluron Monobromo benzene chlorbromuron Monochloro acetic acid see Chloro acetic acid Morpholine dimethomorph, ethofumesate, nipyraclofen Mucochloric acid chloridazon, norflurazon, pyridaben... 

A related synthetic approach makes use of aldehydoacids as starting material. In particular mucochloric acid (35) or other halogenated... 

The kinetics and mechanism of the reactions of trialkyl phosphites with mucochloric acid (dichloroaldehydoacrylic acid) have been studied. Cine-substitution products are formed in reactions of 2,5- and 2,6-dichloro-l,4-benzoquinone with pyrrohdineJ The reaction of vinyl fluoride with CN has been studied by the DFT B3YLP/6-31- -G(d) method. This nucleophilic substitution is mainly a n attack with a barrier height of 14.8kcalmol , which is 17.91 kcalmoC more favovuable than the a attack. 

A kinetic study of the reaction of trialkylphosphites with mucochloric acid has estabhshed that this unusual variant of the Arbuzov reaction proceeds with ehmination of both alkyl halide and HCl at the second stage. a,) -Epoxysulfones (111), on treatment with base, have been found to undergo a new variant of the Ramberg-Backlund reaction and thereby form allylic alcohols (113). ... 

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