1,1 -dichloro-3-methyl-2,5-dihydro

A mixture of 5.7 grams (0.02 mol) of 5-chloro-2,4-disulfamylaniline and 4.9 grams (0.04 mol) of dichloroacetaldehyde in 25 ml of dimethyl formamide was heated at the boiling temperature and under reflux for 30 minutes. The reaction mixture was thereafter poured into a mixture of ice and water to precipitate the desired 6-chloro-7-sulfamyl-3-dichloro-methyl-3,4-dihydro-1,2,4-benzothiadiazine-1,1-dioxide as a crystalline solid melting at 250° to 270°C with decomposition. 

Imidazole, 4,5-dibromo-l-methyl-synthesis, S, 399 Imidazole, 4,5-di-t-butyl-synthesis, S, 483 X-ray diffraction, S, 350 Imidazole, 4,5-dichloro-chlorination, S, 398 synthesis, S, 398, 473 Imidazole, 4-(3,4-dichlorophenyl)-nitration, 5, 433 Imidazole, 4,5-dicyano-hydrolysis, S, 435-436 synthesis, S, 461, 472, 487 Imidazole, 4,5-dicyano-1-vinyl-synthesis, S, 387 Imidazole, 4,5-dihydro-mass spectra, 5, 360 Imidazole, 4-(dihydroxybutyl)-synthesis, S, 484 Imidazole, 4,5-diiodo-nitration, S, 396 synthesis, S, 400 Imidazole, 2,4-diiodo-5-methyl-iodination, S, 400 Imidazole, 1,2-dimethyl-anions... 

Indole, 3-(dialkylaminomethyl-) alkylation, 4, 275 Indole, 2,3-dibromo-synthesis, 4, 215 Indole, 2,6-dibromo-3-methyl-synthesis, 4, 215 Indole, 1,3-dichloro-synthesis, 4, 214 Indole, dihydrodehydrogenation, 4, 283, 311 in non-silver photography, 1, 383 Indole, 2,3-dihydro-synthesis, 4, 327, 352 Indole, 2,3-dihydroxy-tautomerism, 4, 37, 199 Indole, 4,6-dimethoxy-... 

Pyran, 3,4-dihydro-, 55, 63 Pyran, tetrahydro-, 2,3-dichIoro- [2//-Pyran, tetrahydro-, 2,3-dichloro-], 55, 63 Pyran, tetrahydro-, 3-chloro-2-methyl- [2H-Pyran, tetrahydro-, 3-chloro-2-methyl-], 55 63... 

Ethyl a,2-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-0X0-1H-1,2,4-triazol-1-yl]-4-fluorobenzene-propanoate... 

Ethyl 6,7-dichloro-3-methyl-2-quinoxalinecarboxylate Ethyl 6,7-dichloro-3-oxo-3,4-dihydro-2-quinoxalinecarboxylate Ethyl 6,7-diethoxy-3-oxo-3,4-dihydro-2-quinoxalinecarboxylate Ethyl 6,7-difluoro-3-methyl-2-quinoxalinecarboxylate Ethyl 6,7-difluoro-3-methyl-2-... 

Since the publication of CHEC-II(1996), there have been very few examples related to the reactivity of substituents attached to ring carbon atoms. One case involves the reaction of 3-benzylidene-2,3-dihydro-2-methyl-l,2-benzothiazin-4-one 1,1-dioxide 163 with the alkylidenephosphorane derived from salt 164 forming the tricyclic-fused ring compound 165 (Scheme 20) <1996J(P1)2541>. This material 165 was oxidized with 2,3-dichloro-5,6-dicyano-l,4-benzoquinone (DDQ) affording the biphenyl 166. Ring-opened product 167 was produced from 165 upon exposure to />-toluene-sulfonic acid and heat. 

By reacting 2-aminopyridine and epichlorohydrin, Knunjanz187 obtained the hydrochloride of 3-hydroxy-3,4-dihydro-2H-pyrido[l,2-a]pyrimidine (131 R = OH). Analogous products from 4-methyl-, 5-methyl-, 5-halo- and 3,5-dibromo-substituted 2-aminopyridines have been prepared by Soviet workers.188,189 The same products arose from the reaction of 2-aminopyridines and l,3-dichloro-2-propanol.188 189 Klusis and Kuthevicius190 reacted 2-aminopyridine with 3-chloro-1,2-propanediol (127) or 2,3-... 

Addition of tetrahydrofuran (THF) to a solution of dimeric l,2-bis(chloromethylalumino)tetrafluorobenzene 176 induces a ring contraction process that results in the formation of a mixture of three dialacycles (9-methyl-10-chloro-9,10-dihydro-9,10-diala-octafluoroantracene, 9,10-dimethyl-9,10-dihydro-9,10-diala-octafluoroantracene, and 9,10-dichloro-9,10-dihydro-9,10-diala-octafluoroantracene) as confirmed by 1H and 19F NMR spectroscopy (Equation 5) <2000JOM132>. 

C) Preparation of 7-Chloro-2,3-Dihydro-l-Methyl-5-Phenyl-lH-l,4-Benzodiazepine A mixture of 4.7 g (22.6 mol) of 7-chloro-l,2,3,4-tetrahydro-l-methyl-5H-l,4-benzodiazepin-5-one and 100 ml of phosphorus oxychloride was heated in an oil bath at 100°C for 15 minutes. The solution was concentrated to dryness in vacuo. The residue was partitioned between methylene chloride and cold saturated sodium bicarbonate solution. The methylene chloride phase was dried over sodium sulfate and sodium bicarbonate, filtered, diluted with benzene and concentrated in vacuo to produce crude 5,7-dichloro-2,3-dihydro-l-methyl-lH- 1,4-benzodiazepine. 

The 3-chloro-l,7-dimethylpyridazino[3,4-(7][l,3]oxazine-4,5-dione (149) was prepared in a four-step synthesis starting with (Z)-methyl-3-(3,6-dichloro-l-methyl-4-oxo-l,4-dihydropyridazin-5-yl)-2-methylacrylate (146) which is converted with sodium azide into the 6-azido compound (147). Heating in o-dichlorobenzene at 150°C results in cyclization to methyl 3-chloro-l,6-dimethyl-4-oxo-1,4-dihydro(7//)pyrrolo[2,3-c]pyridazine-5-carboxylate (148) via a nitrene intermediate. Ozonolysis effects ring-enlargement of the pyrrole ring into the 3-chloro-l,7-dimethylpyridazino[3,4-d][l,3]oxazine-4,5-dione (149) (Scheme 26) <79JHC1213>. 

The triazine (171) <91 AP(324)65> underwent intramolecular cycloaddition followed by elimination of nitrogen to give the 2,3-dihydro-4-methyl-7-trifluormethylpyrazino[2,3-6][l,4]oxazine (172) (Equation (24)). For a preparation of 6,7-dichloro derivatives see Section 7.19.3.2.4(ii). 

In a similar manner, 3-isobutyl-6-methyl-3,6-dihydro-2,5(l//,4//)-pyrazinedione (9, R = Me) gave 2-chloro-3-isobutyl-6-methylpyrazine (10, R = Me), 2-chloro-6-isobutyl-3-methylpyrazine (11, R = Me), and 2,5-dichloro-3-isobutyl-6-methylpyrazine (12, R = Me) (27, 21, and 4%, respectively).295... 

C5H4N4S 1,7-dihydro-6H-purine-6-thione 50-44-2 25.00 1 4634 2 4478 C5H6CI202 2,2-dichloro-l-methyl-cyclopropanecarboxylic 1447-14-9 22.50 1.3010 2... 

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