How could one convert an oxydiazine, where the oxygen is to a nitrogen, into (i) a corresponding
chlorodiazine and (ii) effi ciently into a corresponding N-methyldiazin-2-one?
How could one transform pyrimidine, in two steps, into pyrimidin-4-one?
How could one transform pyrimidine-2-thione, in three steps, into 2-azidopyrimidine?
What are the structures of the compounds formed: (i) C 6 H 9 IN 2 S from 3-methylthiopyridazine with MeI;
(ii) C 6 H 8 ClIN 2 from 3-chloro-6-methylpyridazine, with MeI; and (iii) C 5 H 2 Cl 2 N 2 O from treatment of
2,6-dichloropyrazine with LiTMP then HCO 2 Et?
What are products in the following ring syntheses:
(i) chlorobenzene reacted with succinic anhydride–AlCl 3 (→ C 10 H 9 ClO 3 ), then this product reacted with
N 2 H 4 (→ C 10 H 9 ClN 2 O) and fi nally this with Br 2 –AcOH (→ C 10 H 7 ClN 2 O);
(ii) 2,5-dimethylfuran reacted with Br 2 in MeOH (→ C 8 H 14 O 3 ) then this product fi rstly treated with
aqueous acid and then hydrazine (→ C 6 H 8 N 2 );
(iii) 4,4-dimethoxybutan-2-one with guanidinium hydrogen carbonate (→ C 5 H 7 N 3 );
(iv) ethyl cyanoacetate with guanidine–NaOEt (→ C 4 H 6 N 4 O);
(v) ethyl cyanoacetate with urea–EtONa (→ C 4 H 5 N 3 O 2 );
(vi) (EtO) 2 CHCH 2 CH(OEt) 2 –HCl–urea (→ C 4 H 4 N 2 O);
(vii) MeOCH 2 COMe with EtO 2 CH–Na (→ C 5 H 8 O 3 ), then this with thiourea (→ C 6 H 8 N 2 OS), then this
with H 2 –Ni (→ C 6 H 8 N 2 O);
(viii) PhCOCH 2 CO 2 Et with EtC(=NH)NH 2 (→ C 12 H 12 N 2 O);
(ix) PhCOCHO with MeCH(NH 2 )CONH 2 (→ C 11 H 10 N 2 O).
