Ethyl (4‐benzyloxyphenyl)‐6‐methyl‐2‐sulfanylidene‐1, 2, 3, 4‐tetrahydropyrimidine‐5‐carboxylate and a redetermination of ethyl (4RS)‐4‐(4‐methoxyphenyl)‐6‐methyl‐2‐sulfanylidene‐1, 2, 3, 4‐tetrahydropyrimidine‐5‐carboxylate, as its 0.105‐hydrate, both at 200 K: subtly different hydrogen‐bonded ribbons. Issue 1 (18th December 2014)

• Record Type: Journal Article
• Authors: Sarojini, Balladka K.; Yathirajan, Hemmige S.; Hosten, Eric C.; Betz, Richard; Glidewell, Christopher
• Is Part Of: Acta crystallographica. Volume 71:Issue 1(2015:Jan.)
• Page Start: 59
• Page End: 64
• Publication Date: 2014-12-18
• Subjects: Crystallography -- Periodicals; Crystals -- Periodicals; 548.3
• DOI: 10.1107/S2053229614026758
• Languages: English
• ISSNs: 2053-2296

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Two sulfanylidene‐1, 2, 3, 4‐tetrahydropyrimidine derivatives have been synthesized using acid‐catalysed cyclocondensation reactions between thiourea, ethyl 3‐oxobutanoate and substituted benzaldehydes. In each of ethyl (4<italic>RS</italic>)‐4‐(4‐benzyloxyphenyl)‐6‐methyl‐2‐sulfanylidene‐1, 2, 3, 4‐tetrahydropyrimidine‐5‐carboxylate, C<sub>21</sub>H<sub>22</sub>N<sub>2</sub>O<sub>3</sub>S, (I), where <italic>Z</italic>′ = 2, and ethyl (4<italic>RS</italic>)‐4‐(4‐methoxyphenyl)‐6‐methyl‐2‐sulfanylidene‐1, 2, 3, 4‐tetrahydropyrimidine‐5‐carboxylate 0.105‐hydrate, C<sub>15</sub>H<sub>18</sub>N<sub>2</sub>O<sub>3</sub>S·0.105H<sub>2</sub>O, (II), the reduced pyrimidine ring adopts a conformation intermediate between the boat, screw‐boat and twist‐boat forms. In (I) and (II), a combination of N—H...O and N—H...S hydrogen bonds links the organic molecules into ribbons containing alternating <italic>R</italic><sub>2</sub><sup>2</sup>(8) and <italic>R</italic><sub>4</sub><sup>4</sup>(20) rings. In (I), the ribbon contains three types of ring, <italic>viz.</italic> two different <italic>R</italic><sub>2</sub><sup>2</sup>(8) rings which are both centrosymmetric and <italic>R</italic><sub>4</sub><sup>4</sup>(20) rings which are not centrosymmetric. In (II), the ribbon contains two types of ring, both of which are centrosymmetric. In compound (II), the ribbons enclose continuous channels which run along the twofold rotation axes in the space group <italic>C</italic>2/<italic>c</italic>, and the partial‐occupancy water molecules lie within these channels. Structural comparisons are made with a number of related compounds.</p> </abstract>