Benzimidoyl chloride

An elegant procedure for the synthesis of 5//-dibenz[c,e]azepines 14, which is an extension of the procedure outlined at the beginning of this section, has been developed in which the nitrile ylides, generated by the treatment of iV-(2-arylbenzyl)benzimidoyl chlorides 12 with potassium /er/-butoxide, undergo a 1.7-electrocyclization at the adjacent phenyl ring, followed by a hydrogen shift 13 - 14.102... 

The deamination of primary amines RNH2 (R = CsHn, PhCH2, PhCHMe or PhCH=CHCH2) to the corresponding hydrocarbons is accomplished by conversion into the benzimidoyl chlorides, followed by reduction with tributyltin hydride in the presence of AIBN (equation 121)398. 

The benzimidoyl chloride (1.6 mmol) in CH2CI2 (10 ml) is added to a stirred mixture of the phenol (2.1 mmol), NaOH (82 mg, 2.1 mmol) and TBA-Br (20 mg, 0.06 mmol) in H20 (6 ml). The mixture is stirred at room temperature for 1 h and CH2C12 (20 ml) is then added. The organic phase is separated, washed well with aqueous NaOH (5%) and H20, dried (Na2S04), and evaporated to give the imidoyl ester. 

Benzimidoyl chloride PhC(NR )Cl % yield of imidate Ph(NR )OAr % yield of amide PhCON(R )COAr ... 

Amino-1,2,3,4-thiatriazole (10) has been described as reacting with equal amounts of JV-phenyl benzimidoyl chloride (109) to give 5-imino-A -l,2,4-thiadiazoline hydrochloride (110) in 80% yield (Scheme 20). The thiadiazoline is decomposed by strong base into JV-cyanoamidine (111) and sulfur, but the free base (112) can be liberated by treatment with bicarbonate. The free base decomposes similarly into V-cyanoamidine (111) and sulfur when heated in chloroform or water. 

The step 1 product (0.25 mol) was dissolved in 220 ml DMF and the mixture treated with /V-methyl benzimidoyl chloride (0.25 mol) at ambient temperature and then stirred for 19 hours and precipitated in 1500 ml of water. The solid was isolated by filtration and dried in vacuo. The crude product (66.06 g) was dissolved in 250 ml of acetonitrile, refiltered, and 58.7 g product isolated as colorless crystals having an mp = 174-176°C. 

Similar imidazolium ylides are implicated in the aroylation of TV-phenyl benzimidoyl chlorides (92CPB2627), and in reactions of 1-substituted imidazoles with cyanogen bromide to form 2-cyano- or 2-bromo-imidazoles (88S470). 

N-Hexylpiperazine N-Isobutyl-benzimidoyl chloride Maleic acid... 

To a solution of 13.6 g (0.08 mol) of N-hexylpiperazine and 8.1 g (11.2 ml), (0.08 mol) of triethylamine in 120 ml toluene, was added 15.6 g (0.08 mol) of N-isobutyl-benzimidoyl chloride over a period of 15 minutes. The reaction mixture was stirred at room temperature for a period of 2 hours. The triethylamine hydrochloride was filtered off and the filtrate concentrated under vacuum. The residual oily base was washed with 20 ml water, extracted with 50 ml ether and dried over anhydrous magnesium sulfate. The dry ethereal solution was then added to a solution of 18.6 g (0.16 mol) maleic acid in 800 ml ether to obtain the dimaleate salt. Two recrystallizations from ethanol yielded 22.5 g (50.2%) of N-[(4-hexyl-l-piperazinyl)phenylmethylene]-2-methyl-l-propanamine product, M.P. 175°-176°C. 

Treatment of (Z)-A-(4-nitrobenzyl)benzimidoyl chloride with base generates the nitrile ylide 1018, which undergoes a 1,3-dipolar cycloaddition with 5,6-dihydropyran-2-one to afford the exo-adduct tetrahydropyran-2-one 1019 as the exclusive product (Scheme 264) <1998T11613>. A 1,3-dipolar cycloaddition of a chiral cyclic nitrone with 5,6-dihydropyran-2-one proceeds with high stereoselectivity to the co-tetrahydropyran-2-one <2000TA2015, 2001TA3163>. 

The interaction between (trifluoromethyl)trimethylsilane and TV-(phenyl)-benzimidoyl chloride (or fluoride) in the presence of a source of the fluoride ion gives 7V-(phenyl)iminotrifluoroacetophenone 23 along with 2,4-di(trifuoromethyl)-2,4-diphenyl-1,3-diazetidine 24 (94UP1). 

Reaction of iV-(2-cyanophenyl)benzimidoyl chloride 66 with sterically hindered thioureas gives intermediate l-[(2-cyanophenylimino)phenylmethyl]thioureas 67 (see also Section 14.08.7.4.2), which are prone to intramolecular S-attack and give 2-phenylquinazoline-4(377)-thione 68 as a final elimination/rearrangement product (Scheme 13 <2002MOL96 . 

Benzimidoyl chloride, N-phenyl-, Friedel-Crafts benzoylation using, 55, 195 Benz[g]indazoles. 5-trifluoroacetyl-3-trifluoromethyl-, 60, 17 Benz[c]indole, 4.5,6,7,8,9-hexafiuoro-2-phenyl-, 59, 14... 

From Anilines and N, -Dimethyl-A"-(trichlorovinyl)formimidamide or A -(1-Chlorovinyl)benzimidoyl Chlorides... 

Anilines 6 react with A,iV-dimethyl-iV -(trichlorovinyl)forniiniidaniide or iV-(l-chlorovinyl)-benzimidoyl chlorides 7 to give 2,4-disubstituted quinazolines 8a ° and Sb. ... 

Benzimidoyl chlorides and )V, -dimethyl-)V -thiobenzoylfoimamidine react to afford thioimidic acid anhydrides (270 Scheme 40). Spirocyclic thioimino esters have been prepared from benzimidoyl chlorides and thiazolin-S-thiones.- Carboxylic acid imidothio acid anhydrides (271) can be synthesized from carboxylic acid chlorides and secondary thioamides. ... 

Schiff base formation in the Busch reaction may be avoided by employing N-( 1 -chlorobenzyl)benzimidoyl chloride, in which the aldehyde one-carbon fragment is already incorporated into the N-(l-chlorobenzyl) moiety both chlorine atoms participate in the reaction with arylhydrazine, to give modest yields of a A3-l,2,4-triazoline (Scheme 5) (79ZOR1181). 

An extension to the above method involves the cyclization of /V-(trichlorovinyl)benzimidoyl chlorides 3 and amidines.409 Thus, in tetrahydrofuran at 25 °C in the presence of triethylamine, the (dichloromethyl)-l,3,5-triazines 4 are formed in 45 to 83% yield. Furthermore, 7V-(1,2,2,2-tetrachloroethyl)benzimidoyl chlorides 5 may be used as starting materials in condensations with benzimidamide hydrochloride.410... 

A(-Phenyl benzimidoyl chloride and the sodium derivative of urethane react to give A(-ethoxy-carbonyl-iv -phenyl phenylformamidine (617), which is a substrate for thermal cyclization to the corresponding quinazolinone (618) (Scheme 98) . 

Treatment of an A(-(aminothiocarbonyl)benzimidoyl chloride (180) with potassium thiocyanate in methanol, or better, in acetic acid, results in cyclization of the initially formed benzimidoyl isothiocyanate (181) to a 1,3,5-thiadiazine-2-thione (182) (Scheme 26). The isocyanates can be isolated if the reaction is carried out in acetone at room temperature, but ring close to the thiones in boiling methanol <88JPR241,89EGP263768>. 

Again one might expect that the benzoderivatives of aromatic six-membered ring imidoyl halides have reactive halo groups. Recently, an interesting route to six-membered ring benzimidoyl chlorides has been reported ( ). Reaction of o-cyanomethylbenzoic acid (LV) with 2 moles of phosphorus pentachloride produces 1,3-dichloroisoquinoline (LVI). 

The significance of imidoyl halides as intermediates in the Beckmann rearrangement has been pointed out earlier (see Chapter 3). In the Chapmann rearrangement imidoyl chlorides are used to prepare imidates, which undergo rearrangement to yield N-aroyl derivatives of diarylamines C ). For example, reaction of the sodium salt of dimethyl 4,6-dihydroxyisophthalate (XIX) with the benzimidoyl chloride XX yields the bis-imidate XXI, which can be thermally rearranged and hydrolyzed to produce the diamines XXII C). 

The hexachloroantimonate salts of unsubstituted imidoyl halides have been converted to the corresponding azides Boron trichloride complexes of N-substituted benzimidoyl chlorides are reported by Hall and co-workers... 

The outlined synthesis of 6,13-dichloroquinacridone 48 [50] (Scheme 18.20) resolved the conjecture [11]. Reaction of the disodium salt of the hydroquinone 44, generated by reduction of 2,5-dichloro-3,6-diethoxycarbonyl-l,4-benzoquinone 37, with N-phenyl-benzimidoyl chloride affords the dibenzimidate ester 45 that rearranges thermally [51, 52] to produce the N-aroyl diphenylamine 46 in excellent yield. Hydrolysis of the latter affords 2,5-dianilino-3,6-dichloroterephthalic acid 47. 

Type H (C—N—C + C—S) Syntheses.—In the course of their detailed studies of nitrile-ylides, Huisgen and his co-workers have examined cycloadditions of benzonitrile 4-nitrobenzylide (27) [arising from N-(4-nitro-benzyl)benzimidoyl chloride, (26 Ar = P-C6H4NO2)] to a variety of carbon-heteroatom multiple bonds. Thus, the interaction of (26) with em excess of methyl dithiobenzoate in triethylamine gave 85% yields of 2,5-diphenyl-4-(4-nitrophenyl)thiazole (29), with loss of methanethiol, two stereoisomeric A -thiazolines (28) being formed intermediately. The same thiazole arose by the use of monothiobenzoate from the primarily formed 5-methoxythiazoline (30) by spontaneous loss of methanol. ... 

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