Synthesis of novel purin-6-yl conjugates with heterocyclic amines linked via 6-aminohexanoyl fragment

N‐[ω‐(Purin‐6‐yl)aminoalkanoyl] Derivatives of Chiral Heterocyclic Amines as Promising Anti‐Herpesvirus Agents

“…To obtain the target 2‐aminopurine and purine conjugates, we have proposed a synthetic sequence represented in Scheme . Recently, we have already applied this strategy for the synthesis of some N ‐[6‐(2‐aminopurin‐6‐yl)]‐ and N ‐[6‐(purin‐6‐yl)]‐aminohexanoyl derivatives starting from racemic and enantiopure amines 1a – c . In this work, we have extended this approach to prepare other N ‐[ω‐(2‐aminopurin‐6‐yl)‐ and N ‐[ω‐(purin‐6‐yl)‐aminoalkanoyl] conjugates.…”

“…Purine conjugates 10a , c – f and 11 , including enantiopure ( R )‐ 10e , ( S )‐ 10e , and ( S )‐ 11 were synthesized in moderate yield (38–69 %) in a similar way starting from 6‐chloropurine and racemic 7,8‐difluoro‐3,4‐dihydro‐3‐methyl‐2 H ‐[1,4]benzoxazine, its enantiomers and ( S )‐3,4‐dihydro‐3‐methyl‐2 H ‐[1,4]benzothiazine (Scheme ). Synthesis of compound ( RS )‐ 10e was described previously …”

“…General Information: Synthesis of racemic compound ( RS )‐ 2e , its ( R )‐ and ( S )‐enantiomers [compounds ( R )‐ 2e and ( S )‐ 2e ], compounds ( S )‐ 3 , ( R )‐ 4 , ( S )‐ 4 , ( R )‐ 8a , ( S )‐ 8a , ( S )‐ 8b , ( R )‐ 8c , ( S )‐ 8c , ( R )‐ 9a , ( S )‐ 9a , ( S )‐ 9b , ( R )‐ 9c , ( S )‐ 9c , and ( RS )‐ 10e was described earlier . ( R )‐3,4‐Dihydro‐3‐methyl‐2 H ‐[1,4]benzothiazine [( R )‐ 1b ],[11e] 2‐acetamido‐9‐acetyl‐6‐chloropurine, 2‐oxa‐1,4‐butanediol diacetate and N ‐(purin‐6‐yl)‐6‐aminohexanoic acid ( 5 ) were obtained according to literature procedures.…”

“…(3 R )‐3,4‐Dihydro‐3‐methyl‐4‐(6‐phthalimidohexanoyl)‐2 H ‐[1,4]benzothiazine [( R )‐3]: Yield 1.42 g (91 %), yellowish oil. [ α ] D 20 = –106 ( c = 0.7, chloroform) [ref . ( S )‐ 3 [ α ] D 20 = +104 ( c = 1.4, chloroform)].…”

Enzymatic synthesis of novel purine nucleosides bearing a chiral benzoxazine fragment

“…The conjugates of 2‐aminopurine with the enantiomers of 7,8‐difluoro‐3,4‐dihydro‐3‐methyl‐2 H ‐[1,4]benzoxazine attached directly to the 6‐position [( R )‐ 1 , ( S )‐ 1 ] and through an aminohexanoyl spacer [( R )‐ 2 , ( S )‐ 2 ] were prepared as described earlier (Krasnov et al., ).…”