2- Pentanone, 4-amino-4-methyl

Primary amines form Schiff bases, (CH3 )2C=NR. Ammonia induces an aldol condensation followed by 1,4-addition of ammonia to produce diacetone amine (from mesityl oxide), 4-amino-4-methyl-2-pentanone [625-04-7] (CH2)2C(NH2)CH2COCH2, and triacetone amine (from phorone),... 

At this temperature 4-(dimethylamino)-3,3-dimethyl-2-butanone, which is formed initially, isomerizes to l-(dimethyl-amino)-4-methyl-3-pentanone. 

The less highly substituted Mannich bases can also be prepared directly from ketones and dimethyl(methylene)ammonium trifluoroacetate by the procedure reported here, which takes advantage of the isomerization of Mannich bases in trifluoroacetic acid. (In acetic acid the Mannich bases undergo elimination of dimethylamine to give a-methylene ketones.) This method is rapid and affords products having an isomeric purity of at least 90% without difficult separations. The 49-57% yield of l-(di-methylamino)-4-methyl-3-pentanone obtained with this procedure compares favorably with the overall yields of amino ketones prepared by the indirect routes mentioned previously. 

This method, an adaptation of a previously described procedure,2- 8-4 has been used with a variety of amino acids and anhydrides to give the following products 1-phenyl-1-propionamidO-2-butanone (75%) 6 acetamidoacetylacetone (60%) 6 N-methyl-acetamidoacetone 6 l-phenyl-2-acetamido-3-butanone (79%) 7 l-phenyl-2-propionamido-3-pentanone (41%) 7 l-phenyl-2-butyr-amido-3-hexanone (27%) 7 a-benzamidopropiophenone (42%) 7 a-benzamido-/3-phenylpropiophenone (44%) 7 1 -phenyl-1 -aceta-midoacetone (72-90%) 8-91-phenyl-1-benzamidoacetone (65%) 8 l-phenyl-2-benzamido-3-butanone (78%) 8 3-benzamido-2-buta-none (65-88%) 8 and 3-acetamido-5-methyl-2-hexanone (73%).10... 

The procedure reported here provides a convenient method for the a-hydroxylation of ketones which form enolates under the reaction conditions. The reaction has been applied successfully to a series of para-substituted acetophenones, 1-phenyl-1-propanone, 3-pentanone, cyclopentanone, cyclohexanone, cycloheptanone, cyclododecanone, 2-methyl cyclohexanone, 2-norbornanone and benzalacetone. In the case of a steroidal example it was shown that a carbon-carbon double bond and a secondary hydroxyl group are not oxidized. A primary amino function, as in the case of p-aminoacetophenone, is not affected.5 Similarly, a tertiary amino ketone such as tropinone undergoes the a-hydroxy at ion reaction.5... 

ANTIBIOTICS - BETA-LACTAMS - MONOBACTAMS] (Vol 3) 4-Amino-4-methyl-2-pentanone [625-04-7]... 

Tetramethyl-3-piperideine (35) may be prepared from mesityl oxide via diacetoneamine (4-amino-4-methyl-2-pentanone) and reaction with acetaldehyde to give 2,2,6-trimethyl-4-piperidone, which is then treated with methylmagnesium iodide and dehydrated.28... 

C6H13CI 2-chloro-4-methylpentane 25346-32-1 386.15 32.975 1,2 8764 C6H13NO 4-amino-4-methyl-2-pentanone 625-04-7 467.43 40.764 ... 

REGIOSELECTIVE MANNICH CONDENSATION WITH DIMETHYL(METHYLENE)AMMONIUM TRIFLUOROACETATE 1-DIMETHYL AMINO-4-METHYL-3-PENTANONE... 

Reaction of 3-pentanone with the commercially available hydrazine (5)-l-amino-2-methoxymethylpyrrolidine (SAMP) affords the corresponding chiral hydrazone. Deprotonation with LDA followed by alkylation and hydrolysis furnishes (S)-4-methyl-3-heptanone in greater than 99% enantiomeric excess. Using the corresponding (R)-hydrazine (RAMP) provides (R)-4-methyl-3-heptanone. 

Ammonia, carbon disulfide and acetone, on the other hand, yield 4,6,6-trimethyl-1,2,5,6-tetrah5 dropyrimidine-2-thione (CCVI) (312). The formation of this substance is explained by the primary formation of ammonium dithiocarbamate acetone and ammonia further form diactoneamine(4-amino-4-methyl-2-pentanone) (CCV) which reacts with ammonium dithiocarbamate to give (CCVI). 

Alkylation of lithiated hydrazones forms the basis of an efficient method for the asymmetric alkylation of aldehydes and ketones, using the optically active hydrazines (5)-l-amino-2-(methoxymethyl)pyrroUdine (SAMP) 59 and its enantiomer (RAMP) as chiral auxiliaries. Deprotonation of the optically active hydra-zones, alkylation and removal of the chiral auxiliary under mild conditions (ozonol-ysis or acid hydrolysis of the A-methyl salt) gives the alkylated aldehyde or ketone with, generally, greater than 95% optical purity. This procedure has been exploited in the asymmetric synthesis of several natural products. Thus, (S)-4-methyl-3-heptanone, the principal alarm pheromone of the leaf-cutting ant Am texana, was prepared from 3-pentanone in very high optical purity as shown in Scheme 1.74. 

This reaction may be achieved by the use of two monofunctional catalysts (hydroformylation and hydrogenation) or one bifunctional catalyst (chloromethyl-ated CSDVB, modified by secondary amino groups with bound RhCl(PPh3)2(CO)) (Fig. 12-13). The rates of the first, second and third stages of the bifunctional catalyst are 5-, 15- and 30-fold higher respectively than those of the two monofunctional immobilized catalysts. We should also mention the oligomerization of butadiene with the hydroformylation of vinyl cyclohexene by Ni-Rh complexes bound to phosphorylated CSDVB and the preparation of 4-methyl-2-pentanone on polymer-immobilized heterometallic complexes, etc. 

Another interesting application is the use of the Kabachnik-Fields reaction for the preparation of cyclic aminophosphonates-l,2-oxaphospholanes and 1,2-oxaphosphori-nanes [37]. 3-Amino-3-methyl-2-ethoxy-2-oxo-l,2-oxaphosphorinane is obtained by aminophosphonylation of 5-hydroxy-2-pentanone. 

---