Electrical charging of non-radioactive aerosols was studied. The mean charge acquired by the poly... more Electrical charging of non-radioactive aerosols was studied. The mean charge acquired by the poly-dispersed and mono-dispersed aerosols is determined for the two cases, viz. with and without the presence of additional ion pairs generated by gamma radiation. The results are separated accordingly by determining average charge acquired by the aerosols in three generation route (atomization, combustion and vaporization & condensation) and compared with the charge acquired in the presence of gamma radiation field. Using theoretical formulation developed by Clement and Harrison, the mean charge acquired by the aerosols (mono-dispersed) for a given concentration of both aerosols and ion pairs were calculated and compared with that of experimental results. The study is extended to determine the mean charge obtained for the distribution of DOP aerosols (poly-dispersed), by varying number concentration of aerosols and number concentration of ionpairs. It is found that the mean charge acquired by the aerosols increases with increase of ion pair concentration for a given concentration of aerosols.
Reactions between secondary amines and phosphorus trichloride (PCl 3) leads to the formation of t... more Reactions between secondary amines and phosphorus trichloride (PCl 3) leads to the formation of the corresponding tris(dialkylamino)phosphines or hexaalkylphosphorus triamides [HAPT: (R 2 N) 3 P]. Reaction of silyl-protected 2′-deoxyinosine and acetyl-protected inosine with the in situ formed HAPT and iodine (I 2) leads to the formation of N 6 ,N 6-dialkyl adenosine and 2′deoxyadenosine. In some cases the stoichiometry of the amine is important as also the use of a tertiary amine base. The effect of amine stoichiometry on the reaction of HAPT with I 2 has been studied by 31 P{ 1 H} NMR.
The combination of PPh 3 /I 2 has been shown to be effective for conversion of a range of carboxy... more The combination of PPh 3 /I 2 has been shown to be effective for conversion of a range of carboxylic acids to 2°, 3°, and Weinreb amides. Simplification of the procedure was possible with the use of polymer-supported PPh 3 /I 2. Weinreb amides produced via the use of polymer-supported PPh 3 could be filtered through a short silica gel plug and used in further transformations. Thus, use of polymer-supported PPh 3 offers potential applicability to diversity-oriented reactions. Formal total syntheses of apocynin and pratosine, as well as syntheses of anhydrolychorinone and hippadine, have been achieved via the use of this amide-forming method. An attempt has been made to gain insight into this reaction.
Electrical charging of non-radioactive aerosols was studied. The mean charge acquired by the poly... more Electrical charging of non-radioactive aerosols was studied. The mean charge acquired by the poly-dispersed and mono-dispersed aerosols is determined for the two cases, viz. with and without the presence of additional ion pairs generated by gamma radiation. The results are separated accordingly by determining average charge acquired by the aerosols in three generation route (atomization, combustion and vaporization & condensation) and compared with the charge acquired in the presence of gamma radiation field. Using theoretical formulation developed by Clement and Harrison, the mean charge acquired by the aerosols (mono-dispersed) for a given concentration of both aerosols and ion pairs were calculated and compared with that of experimental results. The study is extended to determine the mean charge obtained for the distribution of DOP aerosols (poly-dispersed), by varying number concentration of aerosols and number concentration of ionpairs. It is found that the mean charge acquired by the aerosols increases with increase of ion pair concentration for a given concentration of aerosols.
Reactions between secondary amines and phosphorus trichloride (PCl 3) leads to the formation of t... more Reactions between secondary amines and phosphorus trichloride (PCl 3) leads to the formation of the corresponding tris(dialkylamino)phosphines or hexaalkylphosphorus triamides [HAPT: (R 2 N) 3 P]. Reaction of silyl-protected 2′-deoxyinosine and acetyl-protected inosine with the in situ formed HAPT and iodine (I 2) leads to the formation of N 6 ,N 6-dialkyl adenosine and 2′deoxyadenosine. In some cases the stoichiometry of the amine is important as also the use of a tertiary amine base. The effect of amine stoichiometry on the reaction of HAPT with I 2 has been studied by 31 P{ 1 H} NMR.
The combination of PPh 3 /I 2 has been shown to be effective for conversion of a range of carboxy... more The combination of PPh 3 /I 2 has been shown to be effective for conversion of a range of carboxylic acids to 2°, 3°, and Weinreb amides. Simplification of the procedure was possible with the use of polymer-supported PPh 3 /I 2. Weinreb amides produced via the use of polymer-supported PPh 3 could be filtered through a short silica gel plug and used in further transformations. Thus, use of polymer-supported PPh 3 offers potential applicability to diversity-oriented reactions. Formal total syntheses of apocynin and pratosine, as well as syntheses of anhydrolychorinone and hippadine, have been achieved via the use of this amide-forming method. An attempt has been made to gain insight into this reaction.
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Papers by Amit Kumar