Abstract: Crude capronitrile is purified by hydrogenation, subsequent treatment in an acidic medium and subsequent distillation in an alkaline medium, by a process in which(a) 6-aminocapronitrile is converted into crude caprolactam by reaction with water,(b) high boilers and low boilers are separated off from the crude caprolactam from step (a),(c) the crude caprolactam from step (b) is treated with hydrogen at from 50.degree. to 150.degree. C. and from 1.5 to 250 bar in the presence of a hydrogenation catalyst and, if desired, of a solvent to give a mixture A,(d1) mixture A in a solvent is passed, at from 30.degree. to 80.degree. C. and from 1 to 5 bar, over an ion exchanger containing terminal acid groups to give a mixture B1, or(d2) mixture A is distilled in the presence of sulfuric acid, any solvent present being removed before the addition of the sulfuric acid, to give a mixture B2, and(e) mixture B1 or mixture B2 is distilled in the presence of a base to give pure caprolactam.

Abstract: Caprolactam is prepared by reacting a solution of 6-aminocapronitrile with water in the liquid phase at elevated temperatures by a process in which(a) an aqueous solution of 6-aminocapronitrile in the liquid phase is heated without the addition of a catalyst in a reactor A to give a mixture I consisting essentially of water, caprolactam and a high-boiling fraction (high boiler), then(b) the water is removed from the resulting mixture I to give a mixture II consisting essentially of caprolactam and the high boilers, then(c) the caprolactam and the high boilers from mixture II are separated from one another by distillation, and then either(d1) the high boilers from stage (c) are fed into the reactor A of stage (a) or(d2) the high boilers are heated similarly to stage (a) in a further reactor B and then worked up similarly to stages (b) and (c) to give further caprolactam, or(d3) the high boilers are heated under reduced pressure in the presence of a base in a reactor C and the reacted mixture is worked up by di

Abstract: Lactams, in particular epsilon-caprolactam (a basic starting material for the production of nylon 6), are selectively prepared by cyclizing/reacting the corresponding aminonitriles with water, in the presence of a catalytically effective amount of a deactivation-resistant solid metal phosphate having the general formula (II):MH.sub.h (PO.sub.4).sub.n .multidot.(Imp).sub.pin which M is a divalent, trivalent, tetravalent or pentavalent element selected from among those of Groups 2a, 3b, 4b, 5b, 6b, 7b, 8, 2b, 3a, 4a and 5a of the Periodic Table, or mixture thereof, or M=0; Imp is a basic impregnating compound which comprises an alkali or alkaline earth metal, or mixture thereof, together with an electrical neutrality-ensuing counteranion therefor; n is 1, 2 or 3; h is 0, 1 or 2; and p is a number ranging from 0 to 1/3, corresponding to the molar ratio between the moiety Imp and the moiety MH.sub.h (PO.sub.4).sub.n.

Abstract: Invented are sulfonic acid substituted analogues of steroidal synthetic compounds, pharmaceutical compositions containing these compounds, and methods of using these compounds to inhibit steroid 5-.alpha.-reductase, including using these compounds to reduce or maintain prostate size. Also invented are intermediates used in preparing these compounds.

Abstract: A process for selective preparation of lactams which comprises contacting, in the vapor phase, an aliphatic or aromatic aminonitrile having the formula HR.sub.1 N--D--CN wherein D is a divalent organic moiety and wherein R.sub.1 is (C.sub.1 -C.sub.4) alkyl or hydrogen with an effective amount of a silica catalyst, in the form of substantially spherical beads having a BET surface area greater than about 250 m.sup.2 /g, preferably between 300 and 500 m.sup.2 /g, and an average pore diameter less than about 20 nanometers preferably 8-10 nanometers at a temperature in the range of about 200.degree. to about 400.degree. C. and at a hydrogen or inert gas flow with a pressure in the range of about 0 to about 300 kPa, in the presence of: (a) ammonia in an amount equal to from 0 to about 50 mole percent of the molar amount of aliphatic or aromatic aminonitrile present; and (b) water in an amount from at least about 1.

Abstract: Process for the selective conversion of dinitriles into the corresponding lactam by treating the dinitrile with an effective amount of a hydrogenation catalyst such as copper chromite in combination with a co-catalyst, such as titania, at a temperature in the range of from about 200.degree. C. to about 400.degree. C. and at a pressure of at least 50 kPa in the presence of water and hydrogen.