Synthesis of aniline

Preparation of aniline

Preparation of aniline by reducing nitrobenzene with tin

Preparation of aniline by reducing nitrobenzene with tin

Preparation of aniline by reducing nitrobenzene with tin

In a 1 liter round-bottomed flask a mixture of 50 grams of granulated tin and 24.6 grams (or 20.5 ml) of nitrobenzene are placed. The flask is connected to a reflux condenser and through a dropping funnel in the course of about 30 minutes 110 ml of concentrated hydrochloric acid are added in the following manner. About one tenth of the hydrochloric acid is added and the mixture is stirred for a few minutes. The mixture becomes warm and the reaction becomes vigorous. If reaction does not start the flask may be warmed gently, however, no more acid should be added. The reaction should be allowed to proceed briskly, but when there is danger of the boiling becoming too violent the flask is immersed for a time in a cold water to moderate, without completely suppressing, the reaction. When the ebullition begins a second portion of about 10 ml of hydrochloric acid are added. During the addition, the reaction is kept under control but maintained at a good rate by the action of the fresh portion of hydrochloric acid. Furthermore, the mixture should be shaken well in order to bring the nitrobenzene layer completely into reaction. After the acid is all added the mixture is heated for about one-half hour to complete the reduction. The end of the reaction can be recognized from the disappearance of the odor of nitrobenzene and by diluting a few drops of the solution with water, when a perfectly clear solution should be obtained. When the reaction is complete, the flask is cooled and a solution of 75 grams of sodium hydroxide dissolved in 150 ml of water are added. The hydroxides of tin which are first precipitated should all dissolve and the solution should be distinctly alkaline. The content of the reduction reaction is transferred in a steam distillation apparatus and aniline is removed by steam distillation. The aniline passes over, along with water, as a nearly colorless oil. Since aniline dissolves in water to the extent of about 3%, some of the product will be present in the distillate even after the latter has lost the original turbidity. To remove aniline from water the solution is treated with sodium chloride (” salt out “) and the aniline is extracted with ether. About 25 grams of common salt is required for each 100 ml of distillate. The ethereal extract is dried over sodium hydroxide and if the solid largely dissolves in the water which it absorbs it is well to decant from the saturated alkaline solution and a fresh drying agent is added to the ethereal solution. Calcium chloride cannot be used to dry the ethereal solution because it reacts with aniline. After drying for several hours, the ethereal solution is decanted into a large Erlenmeyer flask. Ether is removed by evaporation and the residual aniline is distilled with small amount of zinc dust. The fraction boiling at 180-185° C is collecting yielding 80% of the theoretical amount. Pure aniline is a colorless, refracting liquid boiling at 184.4° C and possessing a peculiar odor characteristic also of many of its homologues. The discoloration which occurs on standing, particularly when exposed to the light, is the result of atmospheric oxidation. A sample which has become very red may be purified by adding a pinch of zinc dust and distilling the material.

Experiments in Organic Chemistry, L. F. Fieser, 149-151, 1941

Preparation of aniline by reducing nitrobenzene with iron

The reduction of nitrobenzene, as well as other aromatic nitro derivatives, is carried out on the large-scale by the use of iron borings. This cannot be satisfactorily imitated in the laboratory; consequently it is usual to reduce nitrobenzene on the small-scale by means of tin and hydrochloric acid. If, however, very finely divided iron or “iron powder ” is used, the reduction proceeds very smoothly, and a good yield is easily obtained.

Preparation of aniline by reducing nitrobenzene with iron

Preparation of aniline by reducing nitrobenzene with iron

120 g of iron, powder together with 160 ml water are placed in a large flask of 2-3 liters capacity with stirring. The flask is warmed slightly, and a few drops of nitrobenzene added. Then 10 g of hydrochloric acid is poured into the flask, and the 100 g of the nitrobenzene in small portions at a time. During addition the flask is well stirred and cooled with cold water. The addition of nitrobenzene and amount of cooling are so arranged that the temperature keeps at about 80-90° C. When the reaction is finished (shown by no further rise in temperature), the contents of the flask are distilled with steam (it is not necessary to make the mixture alkaline) till the distillate is no longer milky. The volume of the distillate is about 400-500 ml. The distillate is transferred to a separating funnel, allowed to settle (if necessary), and the aniline, which forms the lower layer, drawn off. The water (which contains about 3 % of aniline in solution) is saturated with sodium chloride and allowed to stand for some time. The aniline, which rises to the top, is separated with a separating funnel, added to the first portion of crude aniline. The aniline is purified by distillation, were a little water passes over at first and is separately collected; the aniline then passes over at 182° C yielding  50-70 g of aniline. Aniline is colorless oil with a peculiar smell, boils at 184° C.

The Synthetic Dyestuffs and the Intermediate Products from which They are Derived, by J. C. Cain, 200, 1905

IUPAC Name

aniline

InChI

InChI=1S/C6H7N/c7-6-4-2-1-3-5-6/h1-5H,7H2

InChI Key

PAYRUJLWNCNPSJ-UHFFFAOYSA-N

Canonical SMILES

C1=CC=C(C=C1)N

MeSH Synonyms

aniline, aniline aluminium salt, aniline dihydrofluoride, aniline diphosphate (1:1), aniline diphosphate (3:1), aniline diphosphate (4:1), aniline hydrobromide, aniline hydrochloride, aniline hydrochloride-(14)C-labeled cpd, aniline hydrochloride-(15)N-labeled cpd, aniline hydrofluoride, aniline hydrogen iodide, aniline monosulfate, aniline nitrate, aniline perchlorate, aniline phosphate (1:1), aniline phosphate (1:2), aniline phosphate (2:1), aniline phosphonate (1:1), aniline sulfate, aniline sulfate (2:1), aniline sulfate (2:1), (14)C-labeled cpd, aniline, (13)C-labeled cpd, aniline, (14)C-labeled cpd, aniline, 15N-labeled cpd, aniline, 2-(13)C-labeled cpd, aniline, 3-(13)C-labeled cpd, aniline, 3H-labeled cpd, aniline, 4-(13)C-labeled cpd, aniline, conjugate acid, aniline, ion(1+), aniline, magnesium (1:1) salt, aniline, monolithium salt, aniline, sodium salt

Depositor-Supplied Synonyms

ANILINE, Benzenamine, Phenylamine, Aminobenzene, Aminophen, Anilin, Kyanol, Benzeneamine, 62-53-3, Arylamine, Benzidam, Krystallin, Anyvim, Cyanol, Blue Oil, Aniline oil, Anilina, Huile D’aniline, C.I. Oxidation Base 1, Benzene, amino, Anilin [Czech], Rcra waste number U012, CI Oxidation Base 1, C.I. 76000, Caswell No. 051C, Phenyleneamine, Benzamine, ANILINE, ACS, phenyl-amine, Aniline reagent, D’aniline, Huile d’aniline [French], RCRA waste no. U012, HSDB 43, Aniline and homologs, Aniline (and salts), Aniline and homologues, CHEBI:17296, NCI-C03736, Aniline oil, phenylamine, UNII-SIR7XX2F1K, SIR7XX2F1K, Anilina [Italian, Polish], CCRIS 44, UN 1547, BIDD:ER0581, PAYRUJLWNCNPSJ-UHFFFAOYSA-N, EINECS 200-539-3, UN1547, EPA Pesticide Chemical Code 251400, CI 76000, AI3-03053, ANL, benzenaminium, Anilinum, phenyl amine, Benzene, amino-, nchembio.257-comp9, DSSTox_CID_90, Benzene,amino (aniline), AC1Q1HGK, Aniline(S#299)-Liq, ACMC-1AZO2, CHEMBL538, Epitope ID:117704, AC1L1LU6, DSSTox_RID_75359, DSSTox_GSID_20090, KSC178M0R, 542-15-4 (nitrate), 542-11-0 (hydrobromide), 142-04-1 (hydrochloride), 45326_RIEDEL, AC1Q528I, 2424-53-5 (monosulfate), Aniline [UN1547] [Poison], 10400_FLUKA, 45326_FLUKA, 51788_FLUKA, HMDB03012, 45497-73-2 (hydriodide), BENZENE,AMINO (ANILINE), 20305-50-4 (sulfate), Aniline [UN1547] [Poison], MolPort-000-871-542, 10400_SIAL, 132934_SIAL, 242284_SIAL, STR00216, Tox21_200345, AR-1H7359, LS-270, STK301792, ZINC17886255, AKOS000268796, DB06728, MCULE-9347486445, RP18568, RTR-002007, CAS-62-53-3, 542-16-5 (sulfate [2:1]), ANILINE- 2,3,4,5,6-D5, NCGC00091297-01, NCGC00091297-02, NCGC00091297-03, NCGC00257899-01, AJ-70174, AK110130, AN-23725, BP-12047, CJ-15802, MO 08492, S667, 17843-02-6 (phosphate [2:1]), 33921-12-9 (phosphonate [1:1]), 37832-42-1 (phosphate [1:1]), 53894-37-4 (magnesium[1:1] salt), DB-013441, KB-250667, A0463, FT-0622394, 9622-EP2269990A1, 9622-EP2270011A1, 9622-EP2272817A1, 9622-EP2272822A1, 9622-EP2272849A1, 9622-EP2275102A1, 9622-EP2275403A1, 9622-EP2275413A1, 9622-EP2276085A1, 9622-EP2277865A1, 9622-EP2277880A1, 9622-EP2277881A1, 9622-EP2279750A1, 9622-EP2280001A1, 9622-EP2280004A1, 9622-EP2280005A1, 9622-EP2280012A2, 9622-EP2280020A1, 9622-EP2280021A1, 9622-EP2281817A1, 9622-EP2281818A1, 9622-EP2284157A1, 9622-EP2284161A1, 9622-EP2284174A1, 9622-EP2284920A1, 9622-EP2287152A2, 9622-EP2287156A1, 9622-EP2289884A1, 9622-EP2289893A1, 9622-EP2289894A2, 9622-EP2292593A2, 9622-EP2292597A1, 9622-EP2292610A1, 9622-EP2295053A1, 9622-EP2295402A2, 9622-EP2295409A1, 9622-EP2295411A1, 9622-EP2295418A1, 9622-EP2295421A1, 9622-EP2295429A1, 9622-EP2295439A1, 9622-EP2295503A1, 9622-EP2298312A1, 9622-EP2298743A1, 9622-EP2298749A1, 9622-EP2298768A1, 9622-EP2298770A1, 9622-EP2298776A1, 9622-EP2298828A1, 9622-EP2301920A1, 9622-EP2301923A1, 9622-EP2301928A1, 9622-EP2301930A1, 9622-EP2301939A1, 9622-EP2301983A1, 9622-EP2302132A1, 9622-EP2305652A2, 9622-EP2305687A1, 9622-EP2305769A2, 9622-EP2305808A1, 9622-EP2308833A2, 9622-EP2308839A1, 9622-EP2308840A1, 9622-EP2308848A1, 9622-EP2308851A1, 9622-EP2308858A1, 9622-EP2308861A1, 9622-EP2308872A1, 9622-EP2308873A1, 9622-EP2308877A1, 9622-EP2308880A1, 9622-EP2311802A1, 9622-EP2311803A1, 9622-EP2311804A2, 9622-EP2311806A2, 9622-EP2311807A1, 9622-EP2311808A1, 9622-EP2311816A1, 9622-EP2311817A1, 9622-EP2311818A1, 9622-EP2311825A1, 9622-EP2311829A1, 9622-EP2311830A1, 9622-EP2314558A1, 9622-EP2314576A1, 9622-EP2314590A1, 9622-EP2314593A1, 9622-EP2315502A1, 9622-EP2316452A1, 9622-EP2316829A1, 9622-EP2316831A1, 9622-EP2371810A1, 9622-EP2371812A1, 9622-EP2372804A1, 9622-EP2378585A1, C00292, EC 200-539-3, 12588-EP2272517A1, 12588-EP2272813A2, 12588-EP2275395A2, 12588-EP2275409A1, 12588-EP2275469A1, 12588-EP2276085A1, 12588-EP2284920A1, 12588-EP2287940A1, 12588-EP2289965A1, 12588-EP2292586A2, 12588-EP2292601A1, 12588-EP2292602A1, 12588-EP2292603A1, 12588-EP2292618A1, 12588-EP2293650A1, 12588-EP2295402A2, 12588-EP2295421A1, 12588-EP2298729A1, 12588-EP2298737A1, 12588-EP2298739A1, 12588-EP2298740A1, 12588-EP2298741A1, 12588-EP2298771A2, 12588-EP2298828A1, 12588-EP2299509A1, 12588-EP2299510A1, 12588-EP2301920A1, 12588-EP2301936A1, 12588-EP2301983A1, 12588-EP2305769A2, 12588-EP2308926A1, 12588-EP2309564A1, 12588-EP2311825A1, 12588-EP2311826A2, 12588-EP2314558A1, 12588-EP2315502A1, 12588-EP2316831A1, 12588-EP2371810A1, 12588-EP2371812A1, 12588-EP2371813A1, 12588-EP2372804A1, 12588-EP2378585A1, 85560-EP2281861A2, 85560-EP2298749A1, 85560-EP2305657A2, 147630-EP2289877A1, A833829, 3B4-0026, T7100197, Benzenamine,diazotized,coupledwithDyer’smulberryextract, I01-10413, InChI=1/C6H7N/c7-6-4-2-1-3-5-6/h1-5H,7H, ANILINE (SEE ALSO ANILINE HYDROCHOLORIDE 142-04-1), Benzenamine,diazotized,coupledwithaniline,condensationproducts, 146997-94-6, 37342-16-8, 91782-30-8, 97862-10-7

Removed Synonyms

aniline nitrate, Aniline hydrobromide, aniline monosulfate, aniline perchlorate, aniline hydrofluoride, aniline, sodium salt, aniline, ion(1+), aniline aluminium salt, aniline dihydrofluoride, ANILINE SULFATE, aniline hydrogen iodide, aniline, conjugate acid, aniline, monolithium salt, aniline sulfate (2:1), aniline, 3H-labeled cpd, aniline phosphate (1:1), aniline phosphate (1:2), aniline phosphate (2:1), aniline, 15N-labeled cpd, ANILINE HYDROCHLORIDE, aniline diphosphate (1:1), aniline diphosphate (3:1), aniline diphosphate (4:1), aniline phosphonate (1:1), aniline, (13)C-labeled cpd, aniline, (14)C-labeled cpd, aniline, 2-(13)C-labeled cpd, aniline, 3-(13)C-labeled cpd, aniline, 4-(13)C-labeled cpd, aniline, magnesium (1:1) salt, CID6115, c0929, aniline hydrochloride-(14)C-labeled cpd, aniline hydrochloride-(15)N-labeled cpd, aniline sulfate (2:1), (14)C-labeled cpd, C023650, 100849-37-4, 4165-61-1, 4919-17-9

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