Benzaldehyde, dimethylamine

The product can also be prepared from benzaldehyde, dimethylamine, and potassium cyanide in cold acetic acid and aqueous ethanol. ... 

A mixture of 1.5 1. of water and 624 g. (6.00 moles) of sodium bisulfite in a 5-1. beaker equipped with a mechanical stirrer is stirred until solution is complete. Benzaldehyde (Note 1) (636 g., 6.00 moles) is added and the mixture is stirred for 20 minutes, during which time a slurry of the benzaldehyde-bisulfite addition product is formed. A 25% aqueous solution of dimethylamine (1100 g.) containing 275 g. (6.13 moles) of the amine is run in, and stirring is continued as most of the addition compound dissolves. The beaker is immersed in an ice bath, and 294 g. (6.00 moles) of sodium cyanide (CautionI Toxic) is added over a period of 20-25 minutes. 

The procedure described above is a modification of that of Hauser, Taylor, and Ledford2 and of Luten which avoids use of anhydrous dimethylamine. It is related to the procedure of Goodson and Christopher that employs benzaldehyde, aqueous dimethylamine hydrochloride, and potassium cyanide. 

The N-bis-silylated o-phenylenediamine 1511 reacts with DMF at 120°C to give benzimidazole, in 97% yield, and dimethylamine and hexamethyldisiloxane 7, whereas reaction of benzaldehyde with 1511 gives only 29% 2-phenylbenzimida-zole 1513, because the intermediate benzimidazoline 1512 is only rather slowly dehydrogenated to 1513 [52]. Heating of N,N -bis(trimethylsilyl)ethylenediamine 1514 with DMF affords imidazoline 1515 and dimethylamine and HMDSO 7 ]52] (Scheme 9.32). The lactam 1516 cycHzes analogously with SiCU 57/triethylamine in 63% yield to give 1517 ]53]. 

Mix 0.25M substituted benzaldehyde, 0.3M nitroethane, 50 ml dry toluene and 5 ml n-butylamine (or other amine), and reflux 3 hours with a Dean-Stark trap (or prepare the nitro-propene as described elsewhere here). Add 50 g iron powder and 1 g FeCl3 optional) and reflux while adding 90 ml concentrated HCI over 3 hours. Reflux 1 hour more, add 2 liters of water and extract 3 times with ether, then dry and evaporate in vacuum (or steam distill until about 3.5 liters of distillate is obtained extract the distillate 3 times with toluene wash the toluene layers with 7 g NaHS03 in 225 ml of water, then 3 times with water and dry, evaporate in vacuum) to get the ketone. Mix 0.13M ketone, 28 g formamide (or dimethyl-formamide if the N.N-dimethylamine is desired) and 3 ml formic acid and heat at 160°. Add 3 more ml formic acid and heat 16 hours at 170-180° adding formic acid from time to time to keep the pH acid. Distill off the water formed (about 16 ml), cool and extract with 3X70 ml benzene. Distill off the benzene and reflux the residue 7 hours with 30 ml concentrated HCI. Chill, basify with 10% NaOH and extract with 3X70 ml ether. Dry and evaporate the ether in... 

Benzylic amines react with hydrogen peroxide to yield benzaldehydes. For example, 4-bromobenzyl-dimethylamine gives a 60% yield of 4-teomobenzaldehyde. Only six cases were reported, with both di-methylamino and diethylamino groups undergoing the reaction. 

The procedure has been shown applicable to the reductive amination of cyclohepta-none, cyclooctanone, acetophenone, norhomanonc, and benzaldehyde. Amines used include ammonia, methylamine, dimethylamine, morpholine, aniline, and hydroxyl-... 

Normal nucleophilic substitution reactions of alkyl and aryl chloropyrazines have been examined as follows 2-chloro-3-methyl- and 3-chloro-2,5-dimethyl(and diethyl)pyrazine with ammonia and various amines (535, 679, 680) 2-chloro-3(and 6)-methylpyrazine with methylamine and dimethylamine (681, 844), piperidine and other amines (681, 921) 2-chloro-5(and 6)-methylpyrazine with aqueous ammonia (362) alkyl (and phenyl) chloropyrazines with ammonium hydroxide at 200° (887) 2-chloro-3-methylpyrazine with aniline and substituted anilines (929), and piperazine at 140° (759) 2-chloro-3-methyl(and ethyl)pyrazine with piperidine (aqueous potassium hydroxide at reflux) (930,931) [cf. the formation of the 2,6-isomer( ) (932)] 2-chloro-3,6-dimethylpyrazine with benzylamine at 184-250° (benzaldehyde and 2-amino-3,6-dimethylpyrazine were also produced) (921) 2-chloro-3,5,6-trimethylpyrazine with aqueous ammonia and copper powder at 140-150° (933) and with dimethylamine at 180° for 3 days (934,935) 2-chloro-6-trifluoromethylpyrazine with piperazine in acetonitrile at reflux (759) 2-chloro-3-phenylpyrazine with aqueous ammonia at 200° (535) 2-chloro-5-phenylpyrazine with liquid ammonia in an autoclave at 170° (377) 2-chloro-5-phenylpyrazine with piperazine in refluxing butanol (759) but the 6-isomer in acetonitrile (759) 5-chloro-2,3-diphenylpyrazine and piperidine at reflux (741) and 5-chloro-23-diphenylpyrazine with 2-hydroxyethylamine in a sealed tube at 125° for 40 hours (834). 

Analog bildet sich aus 2 Mol Methylen-triphenylphosphoran 90 und 1 Mol a-Chlorbenzyl-dimethylamin 91 neben dem Triphenyl-methyl-phosphoniumchlorid 93 ein Ylid 92, das z.B. mit Benzaldehyd zum 1.3-Diphenyl-alkyl-N,N-dimethylamin 94 umgesetzt werden kann... 

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