134241-00-2

Upstream product

• 108-24-7 acetic anhydride 
• 131357-73-8 2-Amino-4-oxo-4H-3,1-benzothiazin 
• 134241-01-3 methyl 2-(3-acetylthioureido)benzoate 
• 115271-80-2 2-(Thioureido)benzoic acid methyl ester 
• 33942-49-3 N-thiocarbamoyl-anthranilic acid 
• 118-92-3 anthranilic acid 

Relevant academic research and scientific papers

Use of dodecanoyl isothiocyanate as building block in synthesis of target benzothiazine, quinazoline, benzothiazole and thiourea derivatives

Dodecanoyl isothiocyanate (I) reacts additively with anthranilic acid to afford derivatives of thiourea II and benzothiazine III in a one-pot reaction. The cyclisation of thiourea II was achieved using acetic anhydride to form quinazoline derivative IV. The heating of quinazoline IV in acetic anhydride or butan-1-ol gave quinazoline derivatives V or VI, respectively. Benzothiazine III underwent trans-acylation to benzothiazine VII in boiling acetic anhydride. The treatment of IV with hydrazine hydrate, anthranilic acid or ethyl carbazate afforded derivatives of triazoloquinazoline VIII, quinazolinoquinazoline XI or thiosemicarbazide X, respectively. The reaction of I with 2aminophenol or 2-aminothiophenol afforded thiourea derivative XIII or benzothiazole derivative XIV, respectively. Most of the synthesised compounds bear a lauroyl (dodecanoyl) group (a hydrocarbon moiety). The structures of the synthesised compounds were confirmed by microanalytical and spectral data.

Benzothiazinones: A novel class of adenosine receptor antagonists structurally unrelated to xanthine and adenine derivatives

2-(Acyl)amino-4H-3,1-benzothiazin-4-ones and related thienothiazinones were identified as structurally novel antagonists at adenosine receptors (ARs). 6-Methyl-2-benzoylamino-4H-3,1-benzothiazin-4-one (10d) was found to be a balanced AR antagonist with affinity for all human (h) subtypes (Ki hA1 65.6 nM; hA2A 120 nM; hA2B 360 nM; hA 3 30.4 nM), while in rat (r), 10d was a highly potent A 1-selective antagonist (rA1 7.7 nM; rA2A 546 nM; rA2B 679 nM, rA3 >10000 nM). 2-(4- Methylbenzoylamino)-4H-3,1-benzothiazin-4-one (10g) was found to be a potent antagonist at human A2A (68.8 nM) and A3 ARs (23.0 nM) with high selectivity versus the other human AR subtypes. In contrast to A 1 and A3 ARs, A2A and A2B ARs tolerated bulky 2-acyl substituents. tert-Butyl (4-oxo-4H-3,1-benzothiazin-2- ylcarbamoyl)benzylcarbamate (15g, Ki hA2B 186 nM; hA 2A 603 nM) and 4-(4-benzylpiperazine-1-carbonyl)-N-(4-oxo-4H-3,1- benzothiazin-2-yl)benzamide (15k, hA2A 69.5 nM; hA2B 178 nM) were highly selective versus the other AR subtypes. 2-Acylamino-3,1- benzothiazin-4-ones represent novel scaffolds suitable for the development of potent and selective AR antagonists for each of the four receptor subtypes.

3,1-Benzothiazin-4-ones and 3,1-benzoxazin-4-ones: Highly different activities in chymotrypsin inactivation

3,1-Benzothiazin-4-ones are sulfur analogs of the potent serine protease inactivators of the 3,1-benzoxazin-4-one type, which acylate the serine residue within the active site of the enzymes. A series of 2-amino-3,1-benzothiazinones was synthesized, but these compounds showed only very little inhibitory activity toward chymotrypsin, a model serine protease. Detailed investigations revealed that benzothiazinones and benzoxazinones react with identical mechanisms, but benzothiazinones acylate chymotrypsin with much lower rate constants. Investigations of nonenzymatic hydrolysis showed the benzothiazinones to be intrinsically more stable than benzoxazinones. It was concluded from spectroscopic results, that benzoxazinones are highly activated due to the absence of ester-like resonance. 2-Benzoylamino-4H-3,1-benzoxazin-4-one was found to be a new, highly active chymotrypsin inactivator. In contrast, benzothiazinones were found to be resonance stabilized. The contribution of a resonance structure with an exocyclic oxanion to the overall structure of the benzothiazinones and its nonproductive binding to the active site explained their low reactivity toward chymotrypsin.