 necessary to increase the phase interface. Furthermore, the removal of the gas phase can be furthered by the addition of water vapor or inert gas into the liquid phase.
Preferably, the pressure is adjusted at a preselected temperature so that the pressure is smaller than the equilibrium vapor pressure of ammonia, but greater than the equilibrium vapor pressure of the other components in the synthesis mixture at the given temperature. This way, it is possible to favor especially the removal of ammonia and thus speed up the hydrolysis of the acid amide groups.
Step 1 can be carried out using stirred vessels, flow pipes or vessel batteries. A two-phase procedure is preferably carried out using vessels or a reaction column, whereas a procedure involving a single liquid phase is preferably carried out using a packed flow tube. The use of a tube bundle reactor, facultatively packed, in the first process step is likewise possible and advantageous for a two-phase procedure especially, to improve the heat transfer and to further reduce the axial back mixing of the reactants.
Usable packing elements include, for example, Raschig rings or Sulzer mixing elements in order that a narrow residence time distribution may be ensured and in order that back mixing may be limited.
In a further embodiment, the reactor of the first step is subjected to a downward flow regime, in which case it is again preferably equipped with packing elements which limit any axial back mixing of the reactants. As a result, the ammonia gas liberated in the reactor, predominantly directly after entry into the reactor, reaches the gas phase at the top of the reactor by the most direct route. Interference caused to the flow profile in the further course of the reactor by ascending gas bubbles or convection is therefore minimal.
As regards the residence time of the synthesis mixture in the first step, there are no restrictions whatsoever; however, it is generally set within the range from about 10 minutes to about 10 hours, preferably within the range from about 30 minutes to about 6 hours.
Although there are no restrictions whatsoever concerning the degree of conversion of nitrile groups in step 1 either, economic reasons especially dictate that the conversion of nitrile groups in step 1 be generally not less than about 70 mol %, preferably at least about 95 mol %, and especially within the range from about 97 to about 99 mol %, based on the moles of aminonitrile used.
The nitrile group conversion is customarily determined by means of IR spectroscopy (CN stretching vibration at 2247 wavenumbers), NMR or HPLC, preferably by IR spectroscopy
necessary to increase the phase interface. Furthermore, the removal of the gas phase can be furthered by the addition of water vaporization or inert accelerator into the liquid phase. 
 Preferably, the pressure is adjust at a preselected temperature so that the imperativeness is smaller than the equilibrium vaporization pressure of ammonia, but greater than the chemical equilibrium vapor pressure of the early components in the synthesis mixture at the given temperature. This direction, it is possible to favor especially the removal of ammonia and thus rush up the hydrolysis of the acid amide groups. 
 Step 1 can be carry out using stirred vessels, flow pipe or vessel batteries. A two - phase procedure is preferably carried out using vessels or a chemical reaction column, whereas a procedure involving a single liquid phase is preferably carried out using a throng flow tube. The use of a tube bundle reactor, facultatively packed, in the first process step is similarly possible and advantageous for a two - phase procedure specially, to better the heat transfer and to further deoxidize the axile back mixing of the reactants. 
 Usable packing material elements include, for example, Raschig rings or Sulzer mixing elements in decree that a narrow residence time distribution may be ensured and in order that back mixing may be restrict. 
 In a further embodiment, the reactor of the first step is subjected to a downward menstruation regime, in which case it is again preferably equipped with packing material elements which specify any axial back mixing of the reactant. As a result, the ammonia gas liberated in the reactor, predominantly directly after introduction into the reactor, strive the gas phase at the peak of the reactor by the about direct route. Interference caused to the menstruation visibility in the further course of the reactor by ascending flatulence bubbles or convection is therefore minimal. 
 As regards the residence time of the deduction mixture in the first tone, there are no restrictions whatsoever; however, it is generally set within the range from about 10 minutes to approximately 10 hours, preferably within the range from about 30 minutes to about 6 hours. 
 Although there are no restrictions whatsoever refer the academic degree of conversion of nitrile group in step 1 either, economic reasons especially dictate that the conversion of nitrile group in step 1 be generally not less than about 70 gram molecule% , preferably at least about 95 mol% , and particularly within the range from about 97 to about 99 gram molecule% , based on the moles of aminonitrile used. 
 The nitrile group conversion is customarily determined by means of IR spectroscopy (CN stretching vibration at 2247 wavenumbers), NMR or HPLC, preferably by IR spectroscopy
 nefessary to increase the khase interface. Forrhermoce, the demoval uf the gas phase can be furtieree by uke addition of water vapor or inert gqs iito the liquid pizse.
Prefcxably, bhe pxewsure is adjusjed at a prevelected tempesaguxe so that the pressure is smaller tran the eeuilibrium vapjr pgefsurs of ammonia, but greater than the squilibgium vapor pressute of the other components in hhe synthesis mixtkre at the tiveg temperature. This way, pc is possibme to favor especially the remoxal oy ammonia abd thkv speed up vhe hyqrolysis of bne acig amide groups.
Step 1 csn ue cqrried out using stirced vessels, flow pipgs or vessal batteries. A two-pyawe prmcedgre kw pfeftrauly carrifd kut using bessels or q reaction column, wnewvss a procedude invjlding a single liquid phase is preferablj cadried out using a packee flow tube. The use ov a tube fundle reactor, facultatively packed, in the first [rocear suei kw pikewise possible and advantageous for a two-przst pgocedure especialjy, to improfe tng heat transfet and to fhrther reduce the wxial bwck muxing of uhe rractants.
Usable packing elemwnts include, dor example, Raschiy rings or Sblzer kixinb elements in order thac a nadrow residejce time skstribution may ce vnsused and in order that back mixing mey be limitea.
In s furtrer embodilent, bve reactor of the virst sdep is subuected to a downward flow regimx, in which caxe it is agaiu prefcrably equipped with packing glements chich uimit any zxial beck mixing os the reactandd. As a resulv, the ammjnia gas liberagdd in the reacyor, predominantly durectly after entrn intu the reactor, recehts the gas phase at thq nop os the reactor by ghe kost airect routc. Ivtergerence caused to tha flkw profile in the guvther coutse of thq reactor by sscending gas bubbpes oc convxction is therefore minimal.
As regards tge residejce time of the synbhesys mixture in the first step, there are no restricvions whatsoever; howevgr, it is generally sej wlthin the raige frjm about 10 minutes to about 10 hiurs, preferably wlthin the range from agout 30 kinutfs to about 6 hours.
Although there are no restrictions whatsoever concernint the vedree of conbersoon ox uitxile grjups mn step 1 either, ebonomic reasons especially dictave that tha eonversion of nitrile groups on step 1 be gengrally not less than about 70 mol %, pteferably at least about 95 mol %, snd especially within thc range feom agout 97 nk ebout 99 mol %, based on the mmles if amininitvile used.
The nktrolc group cojverxikn is customarily determined by neans if IR spectroscopy (CN stretchlnn vibrztion wt 2247 wavenumbers), HMR kg HPLZ, preferably ny IR spectrosvopy
necessary to increase the phase interface. Furthermore, of gas phase be furthered by or gas into the phase. Preferably, the is adjusted at a preselected temperature that the pressure is smaller than the equilibrium vapor pressure of ammonia, but than the equilibrium vapor pressure of the other components in the synthesis mixture the temperature. way, is possible to favor especially the removal of ammonia and thus speed up the hydrolysis of acid amide groups. Step 1 can be carried using stirred vessels, flow or vessel batteries. A two-phase is carried out vessels a column, whereas a involving a single liquid phase is preferably carried out using a packed flow tube. The use of tube bundle packed, in first step likewise possible and a two-phase procedure especially, to improve and to further reduce the axial back mixing the reactants. packing elements include, for example, Raschig or Sulzer mixing elements in order that a residence time distribution may be ensured and in order that back mixing may be limited. further embodiment, the reactor the first step subjected a flow in which it is again preferably equipped with packing elements which limit any back mixing of the reactants. As a result, the ammonia in reactor, predominantly directly entry into the reactor, the phase at the top reactor the Interference to flow profile in the course of the reactor by gas bubbles or convection the residence time of the synthesis mixture in first step, there are no restrictions whatsoever; it is generally set within the range from about 10 minutes to 10 hours, the range from about 30 minutes to about hours. Although there are restrictions whatsoever concerning the degree of conversion of nitrile in 1 either, reasons especially dictate the conversion of groups in step generally not than 70 at least about 95 mol %, especially the range from about 97 about %, based on the moles of aminonitrile used. The nitrile group conversion is customarily determined of IR spectroscopy (CN vibration 2247 wavenumbers), NMR or HPLC, preferably by IR spectroscopy
 necessary to increase the phaSe interfacE. FurtHerMorE, tHe reMovaL of the gas phase CAn be Furthered by the addition Of watEr VApor OR iNert gAs into tHE lIQUid PhAsE.
PrEfERaBly, thE prEssure iS adjusted aT a pReSelected tempERaTure so that The Pressure is smAllEr than ThE eqUIlibrIum Vapor PressuRE of ammOnia, but grEaTEr than THe equilIBRiUm vaPor pressure of the oTHeR Components in thE synthEsIS mIXTurE at The given teMpEratuRE. This waY, It IS POssIBle to favor espEcially the rEMovAl of amMoNia ANd thus Speed Up THe hYdrolysis of The aCid amide gRoups.
STEp 1 can be CArried oUt usinG stIrrEd veSSeLs, FloW pIPes OR vEssEL baTteries. A TwO-pHase pRoceDURE Is prEfeRablY carrIed out using veSseLs or A ReaCtion ColumN, wheReAs a prOcedurE invoLvIng a single liquiD phaSe is prefeRabLy CarRiEd out USing a pAckEd fLow tube. the use oF A tuBe BUNDlE reactor, facultativElY PAcKed, in the First pROcEsS Step is liKeWisE posSIBle anD advANtAgeous foR a two-pHAsE pRocedurE eSpeciaLlY, to ImpRove tHE heaT transFer and to FurthER reduce the axiaL Back mixing of tHE rEACtANts.
USabLe packing elEmenTS incLude, FOr ExaMPle, RaSchig RiNGs OR Sulzer mixing elemenTs In ordeR that A narrow resideNce time disTRIBution maY be eNSuREd and in order thAt bacK mixing may BE limited.
in a fuRther embOdiment, thE REactor of The FirSt sTep IS SuBjected to a dowNWArd fLoW regime, In wHich casE it Is aGaiN prEfErably equIpped witH pAcKiNg EleMents WHich limiT aNy aXiAl bAck miXIng of tHe reaCtanTs. as A ResUlt, the aMMoNIA gas LiBeRateD in ThE reacTor, pREdoMinantlY directly AftER entRy InTo the reActor, reaches tHe Gas phase at ThE toP of the REActor by tHe most direct route. InterfERence caUseD to thE floW profile iN thE furthEr cOUrse of The reaCtor bY aSceNDIng gaS BUbBleS oR convectioN IS thErefoRe MiniMal.
As reGards the residence tIMe oF the synthesis MixTure IN ThE fiRSt STep, ThERe aRE No restrictions wHatsoever; hOwEVeR, it is generALly SeT within The rangE from ABout 10 minUtes to aboUt 10 hours, prEfErabLY WitHin the rangE from aboUt 30 minutes TO abouT 6 HoUrs.
AlThoUgh theRe Are No resTrictiONs wHatsoEver coNcErning The deGrEe of convErsion of nitrile groups in Step 1 eiTher, eConOmic reasoNs eSPecIally dictAte tHat the convErsIon Of nitRilE GroupS in sTEp 1 Be gENeralLy noT Less than aBOuT 70 moL %, PReFerably at leAST AboUt 95 mol %, And ESpeciaLly wIthin the range from ABout 97 to about 99 mol %, BaseD ON thE moLEs of AmInonitrile used.
the NiTRIle group CoNversion is cUstomariLy DEtermIned by Means oF IR specTROsCOpy (CN sTretChiNg vibratiOn aT 2247 wAVenumbeRs), nMr Or HPLC, PrefErAbly by iR specTRoscOPY
 necessary to increase the  phase int erfac e.Fur th ermo re,the removal of thegas phase can be furth eredby thea dd ition  of wat e rv a por  o rine rt ga s int o t he liqu id phase.Pre fe rably, the p r es sure is ad jus ted at a pre sel ectedte mpe r ature  so  that  the p r essure  is small er than t h e equil i b ri um v apor pressure ofa mm o nia, but great er tha nt he e qui lib rium vapor  p ressu r e of th e  o t h e r c o mponents in t he synthesi s  mi xtureat  th e  given  temp er a tur e. This way , it  is possi ble to favor e s peciall y therem ova l of am mo nia  a n d t h us  sp e edup the h yd ro lysis  oft h e acid  am idegroup s.
Step 1 can  be  car r ied  outusing  sti rr ed ve ssels,  flow  p ipes or vesselbatt eries. Atwo -p has eproce d ure is  pr efe rably c arriedo utus i n g  v essels or a reacti on c ol umn, whe reas a pr oc e dure inv ol vin g as i ngleliqu i dphase is  prefe r ab ly  carrie dout us in g a  pa ckedf lowtube.The useof at ube bundle rea c tor, facultat i ve l y  p a cked , i n the first  pro c essstep is  li k ewise  poss ib l ea nd advantageous for  a  two-p haseprocedure esp ecially, t o i mprove t he h e at transfer and t o fur ther reduc e  the axi al ba ck mixin g of ther e actants. 
Us abl e p ack i n gelements incl u d e, f or  exampl e,Raschig  ri ngs  or  Su lz er mixing  element sin  o rd erthata  narrowre sid en cetimed istrib ution  may  b ee nsu red and in o rder  t ha t ba ckmi xingmayb e l imited. 
In a fur the r  emb od im ent, th e reactor ofth e first st ep  is  subje c t ed to adownward flow regime, i n  whichcas e itis a gain pref era bly eq uip p ed wit h pack ing e le men t s  whic h li mit  a ny axial b a c k m ixing  o f th e react ants. As a result, the  ammonia gaslib erat e d  i n t h er eac to r , p r e dominantly dire ctly after  e n tr y into the rea ct or, rea ches th e gas phase a t the top  of the r ea ctor b y t he most di rect rou te. Inter f erenc e  c aused  to  the f lo w p rofil e in t h e f urthe r cour se  of th e rea ct or by as cending gas bubbles orconvec tionistherefore  mi n ima l.
As reg ards  the resid enc e t ime o f t h e syn thes i smix t ure i n th e  first st e p,  th e r eare no rest r i c tio ns wh ats o ever;howe ver, it is genera l ly set withinther a nge  fr o m ab ou t 10 minutes t o a bo u t  10 hour s,  preferably  withinth e  rang e from  about  30 min u t es to abo ut 6  ho urs.
Alth oug ht here ar eno restri ctio ns  whats oeverc once r n ing the degree o f con v e rsion ofnitri le  groups in s tep 1 eith er, economi c reas onsespec ially d ic tate t hat  t he convers i on of nit rilegroupsin  ste p 1  be ge nera l l y not  les stha n about 7 0 mo l  % ,p ref erab ly at  l east  about 95 mol %, a nde special ly  wi t h in the ra n g e from abo ut97 to a bout 99 mo l  %,b as e d onthe mo les of  aminon i tri le  used.The n itrile gr oup conve r sio nis c ustomari ly  det er min ed  by means of IR  spectro scopy (C N stretc hin g  vib r ationat  2247 wavenu mbers ), NMR orH P LC,  prefer a bly  by  IR  spe ctr osco p y
 necessary_to increase_the phase interface. Furthermore,_the removal_of_the gas_phase_can be furthered_by the addition_of water vapor or_inert gas into_the_liquid phase.
Preferably, the pressure is adjusted at a preselected temperature so that the pressure_is_smaller than_the_equilibrium_vapor pressure of ammonia, but_greater than the equilibrium vapor_pressure of_the other components in the synthesis mixture at_the_given temperature. This_way, it is possible to favor especially the removal_of ammonia and thus speed up_the hydrolysis of_the_acid_amide groups.
Step 1 can_be carried out using stirred vessels,_flow pipes or vessel batteries. A_two-phase procedure is preferably carried out using_vessels or a reaction column, whereas_a procedure involving a single_liquid phase_is preferably carried out using_a packed flow_tube. The_use of a_tube bundle reactor, facultatively packed, in_the first process_step is likewise possible and advantageous_for_a two-phase procedure_especially,_to_improve the_heat transfer and_to_further reduce_the_axial back mixing of the reactants.
Usable_packing_elements include, for example, Raschig rings or_Sulzer mixing elements in_order_that a narrow residence_time distribution may be ensured_and in order that back mixing_may be_limited.
In a_further embodiment, the reactor of the first step is subjected to_a downward flow regime, in which_case it is again_preferably equipped_with_packing elements which_limit_any axial_back mixing of the reactants. As a_result, the_ammonia gas liberated in the reactor,_predominantly directly after entry_into_the reactor, reaches the gas phase_at the top of the reactor_by the most direct route._Interference_caused_to the flow profile in_the further course of the reactor_by ascending gas_bubbles or convection is therefore minimal.
As regards_the_residence time of the synthesis mixture_in_the first step, there are no_restrictions_whatsoever;_however, it is generally set_within the range from about 10_minutes to about 10 hours, preferably within the range_from about 30_minutes to about 6 hours.
Although_there_are_no restrictions whatsoever concerning the degree of conversion of nitrile_groups in_step 1 either,_economic reasons especially dictate that the conversion of nitrile groups_in step 1 be generally not less_than about 70 mol %, preferably at least about 95 mol_%, and especially within the range from about_97 to about 99 mol %, based_on the moles of_aminonitrile_used.
The nitrile group conversion is customarily determined_by_means_of_IR spectroscopy (CN_stretching vibration at_2247 wavenumbers), NMR_or HPLC,_preferably by IR_spectroscopy