Heterocyclic compounds containing guanidine moiety were synthesized and characterized. A novel tautomerism was found in dihyropyrimidines such as 2,4,6,6-tetramethyldihydro-pyrimidine and 2-amino-4,6,6-trimethyldihydropyrimidine by the observation of H-D exchanges on both 2-and 6-methyl protons by the treatment of dihydropyrimidines with $CD_3OD$ in the absence of base under the mild conditions. The ratio of their tautomeric isomers is differentiated according to solvents.
New acyclic nucleosides were synthsized by the reaction of dihydropyrimidines with acyclic chains and characterized.
Melamine which is an important compound in the industrial fields was easily synthesized in 1,1,1,3,3,3-hexamethyldisilazane and the mechanism was examined.
The reaction of urea with α, β -unsaturated ketones did not give cyclized compounds. However, silylated urea was reacted with α, β -unsaturated ketones under catalytic amount of lithium hydroxide to give tetrahydropyrimidine-2-ones in good yields. Silylated diimide is an important moiety which may be converted into silylated guanidine, silylated urea, and silylated thiourea moiety. Silylated diimide was successfully synthesized from bistrimethylsilylurea and triphenylphosphine dibromide in good yield.
2-아미노-4,6,6-삼메틸-1,6-디히드로피리미딘의 자외선흡광도가 메탄올 용매하에서 감소하는 현상과 중수소화 메탄올용매에서, 핵자기공명스펙트럼중, 4-메틸기 수소와 5 위치의 수소(비닐기 수소)의 피이크들이 사라지는 현상으로부터 토오토메리즘( 1,6-디히드로피리미딘 = 1,4-디히드로피리미딘 = 5,6-디히드로피리미딘 )이 존재함을 알수있다. 디히드로피리미딘의 나트륨염을 당과 비슷한 구조를 갖는 할로겐화 비고리화합물과 반응시켜 새로운 비고리누클레오시드를 매우 좋은 수율로 얻었으며 디히드로피리미딘은 1,6-디히드로형태로 포함되어 있음을 알수 있었다. 구아니딘을 1,1,1,3,3,3-육메틸디실라잔에서 가열하여 멜라민을 정량적으로 얻을 수 있었고 시안아미드가 반응중간체임도 알 수 있었다. 비스(삼메틸실릴)우레아를 수산화 리튬 촉매하에서 α,β - 비포화 케톤과 반응시켜 테트라하이드로피리미딘-2-온을 비교적 좋은 수율로 얻을 수 있었으며, 적외선분광법을 이용하여, 디메틸썰폭사이드 내에서 토오토메리즘( 1,2,3,6-사하이드로피리미딘-2-온 = 2-하이드록시-1,6-디히드로피리미딘)이 존재함을 알았다. 비스(트리메틸실릴)우레아와 트리페닐포스핀디브로마이드로부터 비스(트리메틸실릴)카보디이미드를 정량적으로 얻을 수 있었다.
